Patent Grant
7393108
The present invention relates to a technology for interfering against an illegal reproduction of an image from a screen in a projection system.
The U.S. Pat. No. 6,018,374 proposes a technology for interfering against such an illegal activity. This technology is based on a difference between the characteristics of human vision and the image capturing characteristics of image capturing cameras and uses an infrared light as a means of interference. Specifically, an infrared radiation apparatus, which is placed at a position close to or far away from an image projector, radiates an infrared light on a screen, so that a reflective light may radiate into an image capturing camera belonging to an individual who is engaged in an illegal activity. In other words, the illegally captured image may record the optical images of the infrared light that is unrelated to the image being presented. As a result, the quality may be lost in the image, that has been illegally captured, and, in some cases, the illegal activity may be identified. Of course, the infrared light is undetectable to a human, and the viewer may not experience any difficulty viewing the image being presented.
Such a use of the infrared light may make it possible to realize an adequate interference effect and prevention effect. However, a diverse interference technology needs to be established in order to protect critical contents.
The present invention proposes a technology for interfering against image capturing using a visible light that satisfies the following conditions:
Condition 1: Human visual characteristics make it difficult to distinguish between an optical image of the visible light for the interference and an image projected on a screen.
Condition 2: Because of the image capturing characteristics of a means of image capturing, the optical image of the visible light for the interference may be distinguishable from the image on the screen in a recording, when the image on the screen is illegally captured.
An effect similar to the case of infrared light may be realized using the visual light that satisfies these conditions. In other words, information and images, that are not in the content being presented, may be viewed in an image that has been illegally captured but may not be recognizable during a normal viewing.
(A-1) Conditions Required for Visible Light
A visible light that satisfies the conditions 1 and 2, which were described earlier, may provide an interference effect mentioned earlier. These conditions were established through research efforts over the years by the inventors on the human vision characteristics, which have been applied on the present field of technology. These conditions are satisfied by controlling the luminance and chromaticity of the visible light for the interference as described next.
Firstly, chromaticity conditions will be described. For example, when the visible light for the interference and the image being presented are radiated so as to overlap together, it is required that the chromaticity of the visible light for the interference and the chromaticity of the image being presented match or only be slightly off to a degree that may not affect the human vision. Of course, this is to keep the visible light for the interference from being detectable by the human vision.
Therefore, when the image being presented is in color, visible light of different chromaticities are radiated in accordance with overlapping positions within a single image. Of course, if the image being presented is a video image, then the chromaticity may be changed in response to changes of the video image even at a same position of overlap on the screen. If the image being presented is in black and white, then the visible light for the interference does not have to be of varying chromaticity, as long as the chromaticity of the visible light for the interference matches with the color temperature on the screen (image). In other words, the visible light for the interference may remain undetectable by the viewer even as the chromaticity remains constant.
When the visible light for the interference is radiated from a space outside of the screen toward the individual engaged in the illegal activity, the chromaticity of the visible light for the interference should match the chromaticity of the background where the radiation originates. The background chromaticity may be almost constant in most cases, or the chromaticity may also change gradually. Therefore, a visible light of a predetermined chromaticity may be radiated or the chromaticity of the visible light may be controlled based on actual measurement results.
By the way, a difference in the background for the visible light for the interference, i.e. whether the background is a part of the image being presented, is not an essential issue in determining the conditions that the visible light for the interference must satisfy. Therefore, the descriptions below will relate to instances in which the visible light for the interference and the image being presented are overlapped, unless specified otherwise.
Luminance conditions will be described next. The higher is the luminance of the visible light for the interference, the more likely will the shape of the visible light be recognized by the viewer as a noise on the screen. As a result, the viewer will experience a difficulty in viewing the presentation. Therefore, a luminance of the visible light for the interference is required to be approximately the same or less than the viewer's contrast sensitivity increment threshold.
The contrast sensitivity increment threshold is a value defined as follows, when a visual target is viewed within a background light. When the luminance of the visual target is enhanced with respect to the luminance of the background light, an observer may detect a difference between the two, as soon as a difference in luminance is greater than or equal to a certain value. A minimum difference in luminance, at which such a difference is detected, corresponds to the above-mentioned contrast sensitivity increment threshold.
Therefore, it is possible to keep the viewer from detecting an increase in luminance in an area of overlap, as long as the luminance of the visible light for the interference is controlled to be at approximately the same level or a lower level than the increment threshold, which is calculated based on the luminance of the image being presented, with which the overlap takes place. In other words, information other than the main feature presentation may be superimposed without disturbing the audience's viewing.
Although the contrast sensitivity increment threshold may be measured for each viewer, appropriate results may also be obtained in general by taking advantage of research results from the past. For example, Section 2, Chapter 3 of a reference material “Light and Illumination” (Hanz Jurgen Henschell, translated by Reo Mori, Nippon Rikou Shuppankai, Tokyo, 1995) may be used as a reference.
Furthermore, according to Paragraph 1, Section 1, Chapter 4 of another reference, “Bio-information system theory” (Tadahiko Fukuda, Sangyo Tosho, Tokyo, 1995), the increment threshold in general can be easily calculated using the Stevens Law. According to the Stevens Rule, the increment threshold ΔLs can be expressed by the following equation.
ΔLs=k(L−L′)^b (1)
where L is an adaptation luminance, L′ is an absolute luminance threshold, and k and b are constants and are values that change with viewing conditions.
Information other than the main feature presentation can be superimposed with the image being presented without being detected by the majority of viewers by controlling the radiation of the visible light for the interference at a luminance that is lower than or equal to a value thus calculated.
By the way, video camera's sensitivity in distinguishing a difference in the optical intensity is not very different from the increment threshold of the human eyes. For this reason, the inventors focused on a difference between the optical spectrum sensitivity curve (relative luminous efficiency) for the human eyes and the optical spectrum sensitivity curve (sensitivity to the received light at various wavelengths) for the video camera, in order to examine additional conditions.
The description next will be based on
As shown in
In fact, while the human optical spectrum sensitivity is at almost 0 at 400 nm on a side of short wavelength or 700 nm at a side of long wavelength, the video camera's optical spectrum sensitivity is 0.6 at 400 nm on a side of the short wavelength and 0.7 at 700 nm on a side of the long wavelength, according to
Accordingly, effects described next may be realized as a result of a radiation of a visible light for the interference that satisfies the conditions listed above. Firstly, the chromaticity of the visible light is similar to the image being presented, and the luminance is less than or equal to the contrast sensitivity increment threshold. As a result, the viewer cannot distinguish between the two. Even when the visible light for the interference is projected on a specific spot on the screen on which the image being presented is projected, the image at this projection spot may seem uniform, and an existence of the visible light for the interference may not be detected.
On the other hand, the video camera can record the light and shade of the contrast in the object being image captured, that may not be detectable to the human because of the differences in the optical spectrum sensitivities. Therefore, by radiating the visible light for the interference that satisfies the conditions listed above so as to overlap with the image being presented, it is possible to make the optical image of the visible light for the interference show up and be distinguishable in the captured image, when the image being presented is illegally captured. For example, a desirable marking that is unrelated to the image being presented may be recorded on the screen, if an optical image of an arbitrary shape were used as the visible light for the interference.
(A-2) Generating Optical System for the Visible Light
A generating optical system for the visible light that satisfies the conditions listed above will be described. As mentioned earlier, the chromaticity of the visible light for the interference is required to match the background chromaticity in the direction from which the light is emitted. The background chromaticity may correspond with the chromaticity of the image that is projected on the screen, as mentioned earlier, or may correspond with the chromaticity of the light arriving from an object that exists outside of the screen. In either of these cases, it is necessary to generate a visible light with a arbitrary luminance and chromaticity.
Such a visible light can be generated by a visible light radiation apparatus having a configuration described next. For example, as shown in
In the figure, 3 refers to a projection optical system. The projection optical system 3 consists of projection lenses and other optical devices.
The optical volume adjustable apparatuses 4R, 4G and 4B, which are placed in the optical paths for the various single colored lights, which come into the mixer optical system 2, is characteristic of
While the three types of single colored light sources are set up independently in
(A-3) An Example of a Layout of the Visible Light Radiation Apparatus
A layout that may be used for the visible light radiation apparatus will be described next. An example of the layout that will be described next may be used for both an image projected from a front side of the screen, as shown in
The method of placing the projection apparatus 5 in front of the screen 6, as shown in
Coming back to the description of the visible light radiation apparatus, the visible light radiation apparatus may be placed at the following locations. For example, as shown in
As shown in
Or, as shown in
Or, as shown in
Although a single unit of the visible light radiation apparatus is shown in each of
(A-4) Method of Synchronizing the Luminance and Chromaticity With the Image Being Presented
A method of synchronizing the visible light, that is used for the interference, with the image being presented will be described next. In other words, a method of variably controlling the luminance and chromaticity of the visible light used for the interference, in response to the image being presented, will be described. If the visible light for the interference passes through a space outside of the screen, then the method may be used in a system for synchronizing the chromaticity and luminance of the visible light, which is used for the interference, with a background light.
The image being presented and the visible light radiation apparatus may be synchronized, for example, using the following methods. The visible light radiation apparatus may be controlled based on information calculated in real time. Or, the visible light radiation apparatus may be controlled using information calculated in advance. The former method is used for projecting the image being presented using a digital type projection apparatus. The latter method is used for projecting the image being presented using a film based projection apparatus.
(1) First System Example
The image data memory 12 records the image data for the main feature program presentation. The image data memory 12, however, does not need to store the entire image data for the entire screen and may, instead, the store image data related to positions at which the visible light for the interference will be superimposed. The image data read-out unit 13 reads out a frame number for the image data or a comparable data number from the image data memory 12. By the way, the image data read-out unit 13 needs to read out the image data only when the visible light for the interference is radiating. For example, the reading may take place once every few frames or when the scene changes. The unit of reading may be a single frame or a plurality of frames.
The radiation data calculation unit 14 calculates the chromaticity and luminance of the image data for each frame number (and for each position of superimposition, when the visible light for the interference is superimposed at a plurality of locations within a single frame). In general, the image data for the presentation consists of primary color data for red, green, and blue. Therefore, the radiation data calculation unit 14 uses directly the chromaticity data, in the image data for the presentation, for the chromaticity data for the visible light for the interference. On the other hand, the luminance data needs to be below the human contrast sensitivity increment threshold. The radiation data calculation unit 14 calculates the appropriate luminance values using, for example, the equation (1) described earlier. These calculation processes take place before the applicable image is projected onto the screen.
The radiation data memory 15 temporarily stores the radiation data calculated by the radiation data calculation unit 14. In other words, the radiation data memory 15 functions as a buffer for storing the calculated radiation data until the radiation data is read out.
The radiation data read-out unit 16 reads the radiation data, which corresponds with the frame number, or a data number, that is assigned to the image being presented that is to be projected, from the radiation data memory 15. The frame number or the corresponding data number, that is assigned to the image being presented, is provided by the projection apparatus that projects the image being presented.
While the description here is based on the visible light radiation apparatus, which radiates the visible light for the interference, being a separate unit from the projection apparatus, that projects the image being presented, the two units may also make up a single unit.
By the way, the luminance of the image being presented may be adjusted down by an amount calculated for the luminance of the visible light for the interference, in this instance. In the case of a single unit, an optical system and other parts are used for both the interference optical system and the image presentation optical system, and a misalignment and a chromaticity mismatch, which may be caused by differences in optical characteristics, may no longer be an issue. Of course, optical systems having equivalent characteristics may be used for the interference optical system and for the presentation optical system, when the two apparatuses are separately provided.
(2) Second System Example
A system example in
The image data memory 18 stores data collected in advance using, for example, a spectrum radiance luminance meter on the image being presented, which is projected onto the screen during, for example, a test screening. Of course, the image data memory 18 does not need to store the image data for the entire screen and, instead, may store only the image data corresponding with the positions at which the visible light for the interference is to be superimposed. The image data read-out unit 19 reads out a frame number for the image data, or a corresponding data number, from the image data memory 18. The image data read-out unit 19 needs to read out the image data only when the visible light for the interference is to be radiated. For example, the readout may take place once every few frames or when the scene changes. The unit of readout may be a single frame or a plurality of frames.
The radiation data calculation unit 20 calculates the chromaticity and luminance of the image data for each frame number (or for each position of superimposition, when the visible light for the interference is to be superimposed at a plurality of locations in a single frame). In general, the image data for the presentation consists of primary color data of red, green and blue. Therefore, the radiation data calculation unit 20 uses the chromaticity data for the image being presented directly for the chromaticity data for the visible light for the interference. On the other hand, the luminance data is required to be equal or less than the human contrast sensitivity increment threshold. The radiation data calculation unit 20 calculates the applicable luminance values using, for example, the equation (1) described earlier. The calculation process takes place before the corresponding image is projected onto the screen.
The radiation data memory 21 temporarily stores the radiation data calculated by the radiation data calculation unit 20. In other words, the radiation data memory 21 functions as a memory apparatus for storing the calculated radiation data until a time the image is projected on the screen. The memory apparatus may be based on a magnetic recording medium, an optical recording medium, an opto-magnetic recording medium, or a semiconductor memory.
By the way, the processing contents of the preprocessing unit may be executed by a server apparatus which is connected by a network, and downloaded before or during the projection of the image being presented. In such an instance, a communications apparatus for downloading and a memory apparatus for storing data that has been downloaded are required at each projection position, which functions as a client.
The real time processing unit 17B includes a radiation data memory 21 and a radiation data read-out unit 22. The radiation data read-out unit 22 reads the radiation data, corresponding to the frame number assigned to the image in the presentation, that is to be projected, or the corresponding data number from the radiation data memory 21. By the way, the frame number assigned to the image being presented or the corresponding data number is provided by the projection apparatus that projects the image being presented.
(A-5) Experimental Results
An example of a assumed system for the embodiment will be described first. When the image being presented is projected using a projector, a white color light source, such as a halogen lamp or a metal hydride lamp, will be used as an optical source. The image being presented is shown on a screen, as a beam of light radiates from the source of white color light, passes through a color filter, and is projected using an optical system. In the present invention, the visible light, that satisfies the conditions described earlier, is projected onto specific areas of the image being projected. In other words, the visible light, having the same chromaticity as the image being presented and a luminance level that is approximately the same or below the human contrast sensitivity increment threshold, which is obtained based on the image being presented, is projected onto the screen.
Assuming such an embodiment, the inventors of the present invention have verified an effectiveness of the present invention using an experimental system shown in
On the other hand, the visible light radiation apparatus, that radiates the visible light for the interference, includes an integration sphere 25, which includes three types of single colored light sources and is driven by an arbitrary waveform generator 26. A red color LED is the HLMPD 105, which is manufactured by Hewlett Packard. A green color LED is the NSPG 500S, which is manufactured by Nichia Chemical. A blue color LED is the NSPB 500S, which is manufactured by Nichia Chemical. The arbitrary waveform generator 26 is the AWG 2005, which is manufactured by Sony Tectronix.
As a composition means 27 for the visible light, which is emitted by the two parts, a plate beam splitter (half mirror) is used. An apparatus mentioned below is placed in an area 28 as an apparatus for verifying how the visible light, after the composition, is image captured. A luminance meter (BM-5A, manufactured by Topcon) is placed for measuring the chromaticity and luminance. The CCD-MC100, which is manufactured by Sony, is used as a video camera for image capturing. The GV-D900, which is manufactured by Sony, is used as a video deck that includes a display unit for verifying the images being recorded.
Measurement results were as follows. Firstly, a measurement was taken only for the visible light radiating from the surface emission light guide, and the result for the xy chromaticity was (x, y, L (luminance, cdm ^−2))=(0.448, 0.419, 40.2), which may correspond with an image that was projected using the white color light source.
Next, a visible light, which is 10 mm square in size and radiating from the integration sphere, is superimposed on the image, and measurements were taken at the area of overlap. The volume of light from the integration sphere is adjusted, so that the measurement taken at the area of overlap may be (x, y, L)=(0.448, 0.419, 41.0). In other words, the chromaticity in the area of overlap with the visible light from the surface emission light guide is made to match the area with only the visible light from the surface emission light guide, while the luminance is increased only by the increment threshold, by adjusting the volume of light from the integration sphere.
An observer observing the result was not able to distinguish between the area, with only the visible light from the surface emission light guide, and the area of overlap, with the visible light from the integration sphere and this visible light. On the other hand, an image, that has been captured using a video camera and shown on a display, showed a contrast difference between the two. In other words, it was verified that a person may not be able to make a distinction, but the visible light for the interference may be recorded in the image captured illegally using the video camera.
Next, a conceptual embodiment that will be applicable to the various embodiments based on the visible light, that satisfies the Condition 1 and the Condition 2, will be described.
(1) A method is proposed for interfering against illegal activities by radiating a visible light for the interference from a viewer's side toward a screen and using a reflected light from the screen surface. In this instance, the visible light for the interference is projected from the front of the screen toward the screen. This embodiment corresponds with
By the way, the projection apparatus, that projects the image being presented, may be placed in front of the screen, as shown in
(2) A method is proposed in which a visible light for the interference is radiated from behind the screen onto the screen, and a light transmitting through the screen and reaching the viewer is used for interfering against an illegal activity. In other words, the visible light for the interference, which is projected from behind the screen toward the screen surface, transmits through the screen toward the front side of the screen in the proposed method. This scheme corresponds with
By the way, the following transmission paths are possible for the visible light for the interference, based on the structure of the screen. For example, when a part of the screen is thinner than other areas on the screen (for example, the screen has a concave shape), then the transmission may take place in this particular area. Or, if a material that may easily allow the visible light to transmit through is embedded into a part of the screen in order to allow the visible light for the interference to transmit through, then the visible light may transmit through this material. If the entire screen is made of a material that may easily allow the visible light to transmit through, then the visible light may transmit through any part of the screen.
In these instances, the projection apparatus, that projects the image being presented, may be placed in front of the screen, as shown in
(3) A method is proposed, in which a visible light for the interference is radiated onto a screen from behind the screen, and a passing light, that passes through an part for passing in the screen, is emitted toward the viewer in order to interfere against an illegal activity. In other words, the visible light for the interference is projected from a position behind the screen toward the screen surface and passes through the screen and travels toward the front of the screen in the method being proposed. This scheme corresponds with
This part for passing may be a break or a gap (for example, a slit), that extends in one direction; a hole portion that penetrates through the screen (for example, a small hole or a hole); or other structures that may allow the visible light to pass through from the back side to the front side of the screen. There should be at least one passing part created on the screen. If there is a plurality of passing parts, then the location for passing may be made selectively variable. Furthermore, the passing part may be laid out across the entire screen or may be concentrated at a specific area (for example, at the center of the screen or at the periphery of the screen). An example is shown in
(4) A method is proposed in which a visible light for the interference is reflected off a means of reflection, and a reflected light is radiated onto the screen. As explained in (2) and (3), the visible light for the interference, that is projected onto the screen, is not limited to those directly projected from a visible light radiation apparatus. When a means of reflection, such as a mirror is used instead, a higher degree of freedom is allowed with the position for installing the visible light radiation apparatus.
The means of reflection or its reflection surface may be capable of arbitrary changing the direction of reflection by a means of driving. Even when the visible light for the interference is projected to a plurality of areas, the visible light radiation apparatus may not need to be installed for all of such areas, when the means of driving is utilized. In other words, an interference over a wider range is made possible. Furthermore, the means of driving may be used as a means of adjustment for precisely targeting the position of the visible light for the interference on to a target pixel.
By the way, the present embodiment may be used for both the visible light for the interference radiating from the front of the screen or for the visible light for the interference radiating from behind the screen. Of course, the position of the projection apparatus, which projects the image being presented onto the screen, may not be limited to any particular position.
(5) A method is proposed in which visible lights for the interference in prescribed combinations are radiated onto a plurality of spots on a screen, so that a two dimensional optical image pattern may be simultaneously recorded with an image on a screen that is illegally captured. In the present embodiment, optical images, such as those shown in
With this method, desirable information may be displayed based on the positions of the optical points and the number of optical points displayed simultaneously. For example, the desirable information may include an output time and date, an output location, a screen number (a unique number that identifies the screen), an output apparatus number (a unique number that identifies the output apparatus), and other information required for identifying a party involved in the output, as well as a location of the illegal activity. Any piece of information or a plurality of pieces of information may be represented using binary optical point image patterns.
If the shapes of the point image were variable, then even more information could be displayed. Instead of assigning meanings to the recorded positions of the optical points or the number of optical images displayed simultaneously, a meaning may also be assigned to a two dimensional shape (a geometric shape, a symbol, and other recognizable patterns), that is presented by the entire point image.
The optical image pattern may remain the same throughout the screening of the image being presented or may be changed periodically or irregularly. Furthermore, the optical image pattern may be projected throughout the entire screening of the presentation or may be projected intermittently.
Of course, the visible light radiation apparatus may be placed in front of the screen or behind the screen in the present embodiment. Furthermore, the projection apparatus for projecting the image being presented may be placed in front of the screen or behind the screen. The visible light for the interference, which is radiated onto the screen, may be reflected off a means of reflection.
If an objective is to make it difficult to view the captured image, then the visible light for the interference should be radiated in such a way that a large number of optical images may be recorded. Or, the projection positions (lighting positions) of the visible light may be changed in a desired manner.
(6) A method is proposed in which, when an image being presented is projected onto a screen by a means of film based projection, a white color light for the interference, a luminance of a target image pixel of which is determined based on an average luminance between a preceding shot and an ensuing shot, is radiated onto the target image pixel on the screen during a time period in which the projected light is shuttered by a frame forwarding shutter. This method is used particularly for black and white images, which are projected using a film based projector apparatus. The present method is characterized in that an emission period for the white color light (the visible light) for the interference is limited to periods in which the frame forwarding shutter is closed.
By the way, the length of time during which the frame forwarding shutter shutters the projection light may be detected or predicted based on a frame forwarding operation or directly detected or predicted based on the operation of the frame forwarding shutter.
Of course, no additional restrictions are imposed other than the requirement on the timing of projection for the white color light for the interference. The white color light for the interference may be projected from the front side of the screen or projected from the back side of the screen. Furthermore, the image being presented may be projected from the front side of the screen or projected from the back side of the screen. By the way, the white color light for the interference only needs to be radiated during some of the time periods in which the frame forwarding shutter is closed and not during all of the time periods. Furthermore, the white color light for the interference may be radiated during the time periods in which the image being presented is shown in a way similar to the other examples.
(7) A method is proposed in which a visible light for the interference, a luminance and chromaticity of a target image pixel of which is determined based on an average luminance and an average chromaticity between a preceding frame and an ensuing frame, is radiated on the target image pixel during a time in which a frame forwarding shutter shutters a projection light, when an image being presented is projected onto a screen using a film based means of projection. This method is used in particular for the images being presented that are in colors. Other aspects are similar to the method in (6).
(8) A method is proposed in which a direction of radiation of the above-mentioned visible light for the interference is adjusted automatically, when a screen size (or aspect ratio) is changed. When the screen size is changed, the image pixel, onto which the visible light for the interference should be projected, moves physically. Consequently, the position from which the visible light for the interference is projected is required to be adjusted. However, this process is extremely burdensome to execute manually. On the other hand, an operator may only need to take into account the screen size, when performing the task, if an automatic adjustment feature were loaded. Efficiency may be significantly improved.
(9) A method is proposed in which a visible light for the interference passes through a space outside of a screen and is directly radiated on the viewer. In this instance, the visible light for the interference is reflected off or radiated from an object other than the screen and is superimposed with a background light. It goes without saying that, even in such an instance, the visible light for the interference may remain undetectable to a human, as long as the chromaticity and the luminance satisfy the condition 1 and the condition 2, which were described earlier, with respect to the background light.
(10) A method is proposed in which a visible light for the interference is radiated from an optical source behind a screen surface and transmits through the screen to the audience. This method represents a special form of the method described in (2). In other words, the visible light for the interference is radiated from a position that is close to the screen back side or adjacent to the screen back side. The point of emission for the visible light for the interference may be adjacent to the screen back side or may face the screen with a small gap in between.
The path of transmittance may be similar to the example described in (2). This method may be applied on the image presented with a projection from the front of the screen or with a projection from the back of the screen.
(11) A method is proposed in which a visible light for the interference is emitted from an optical source on a back side of the screen and passes through a passing part in the screen and reaches the viewer directly. This method is a special form of the method described in (3). In other words, the visible light for the interference is emitted from a position that is close to the back side of the screen. In this instance also, the point of emission of the visible light for the interference may be adjacent to the screen back side or may face the screen backside with a small gap in between.
The screen used in this instance is similar to the one described in (3). This method may be applied for the image being presented that is projected from the front of the screen or from the back of the screen.
(12) A method is proposed in which a visible light for the interference is emitted out of an optical source, that is embedded in a screen, and emitted directly to the audience from the screen surface. The embedded optical source may be detachable from the screen or may comprise a single unit with the screen. The point of emission in the embedded optical source may be buried within the screen or may be exposed at the surface of the screen. By the way, when the point of emission in the optical source is buried within the screen, the visible light for the interference is emitted from the screen surface after passing through or transmitting through a part of the screen. By the way, the image being presented may be projected from the front of the screen or projected from the back of the screen.
(13) A method is proposed in which visible lights for the interference are emitted from a plurality of spots on a screen in a prescribed combination in order to have a two dimensional optical image pattern be recorded, when the image on the screen is illegally captured. This method corresponds with the method described in (5). In the method in (5), the visible light for the interference was radiated onto the screen. The present method differs in that the visible lights for the interference are radiated out of a plurality of points on a screen.
(14) A method is proposed in which a white color light for the interference, based on an average luminance between a preceding frame and an ensuing frame at target pixels, are radiated from the target pixels on a screen, during a time period in which a frame forwarding shutter shuts out a projection light in a film based projection means, which projects an image being presented onto the screen. This method corresponds to (6). While the method in (6) was based on a projection of the white color light for the interference onto the screen, the present method is based on the white color light for the interference radiating from the screen.
(15) A method is proposed in which a visible light for the interference, based on an average chromaticity and an average luminance of a preceding frame and an ensuing frame at target pixels, is radiated from the target pixels on a screen, during a time period in which a frame forwarding shutter shuts out a projection light in a film based projection means for projecting onto a screen an image being presented. This method corresponds with (7). While the method in (7) was based on a visible light for the interference being projected onto the screen, the present method differs in that the visible light for the interference is radiated from the screen.
(16) A method is proposed in which an illegal activity is interfered with by radiating a visible light for the interference from the front of a screen in a system for interfering against image capturing and by using a reflected light off of the screen surface. The present system represents an application example for the method described in (1). Therefore, the descriptions in (1) are applicable on the present system. Of course, the visible light radiation apparatus described in (A-2) is used. Furthermore, as described in (A-4), the visible light for the interference and the image being presented are synchronized, just as in other systems that will be described later.
(17) A system for interfering against image capturing is proposed, which interferes against an illegal activity by radiating a visible light for the interference from behind the screen and by using a transmitted light, that transmits through the screen toward the viewer. The present system represents an application example for the method described in (2). Several forms of transmittance are possible based on the structure and material of the screen.
(18) A system for interfering against image capturing is proposed, which radiates a visible light for the interference from behind the screen and uses a passing light, that passes through the passing part of the screen toward the viewer, in order to interfere against an illegal activity. This system represents an application example for the method described in (3). Several forms of passing parts, with various shapes and structures, are possible.
(19) A system for interfering against image capturing is proposed, which relies on a means of reflection in order to reflect a visible light for the interference and to radiate a reflected light on a screen. The present system represents an application example for the method described in (4). The means of reflection itself or the image capturing interference system may provide a means of drive for a reflection surface, in order to adjust the reflection in any direction. When the direction of reflection is variable, it is possible to precisely position the point of projection and to project the visible light for the interference toward a plurality of areas using a small number of visible light radiation apparatuses.
(20) A system for interfering against image capturing, which includes a plurality of units of the visible light radiation means, is proposed. The visible light radiation means includes a means of control for projecting the visible lights for the interference in prescribed combinations onto a plurality of areas on a screen, so that, when an image on the screen is illegally captured, a two dimensional optical image pattern may be recorded simultaneously. The present system represents an application example for the method described in (5).
The control apparatus may be a, for example, a computer, an application specific semiconductor device, or other electronic circuits. The control apparatus may be realized by hardware or software. A means of switching may also be used, when the two dimensional optical image patterns are switched periodically or are projected intermittently. For example, a means of switching may be utilized, in which the emission of light is switch controlled in response to a clock or its frequency divided output. Furthermore, another means of switching may be utilized, in which the emission is switch controlled in response to a charging and a discharging of a capacitor. In yet another example, a mechanical means of switching may be used.
When some form of information is to be encoded into the optical image pattern, a means of table may be provided that establishes correlation relationships between the optical image patterns and the information. The radiation of the visible light radiation means may be controlled, based on the information contained in the means of table, when the visible light for the interference is radiated.
(21) A system for interfering against image capturing is proposed for an image being presented on a screen by a projection method using a film based means of projection. The image capturing interference system includes a visible light radiation means for radiating a white color light for the interference onto the screen; a shutter cycle detection means for detecting the time periods during which a frame forwarding shutter shutters the projected light; a means of calculation for determining a luminance of the white color light for the interference based on an average luminance in a previous frame and an ensuing frame in the target image pixels; and a means of control for projecting the white color light for the interference onto the target image pixels during the time period in which the projection light is shuttered. The present system represents an application example for the method described in (6). In other words, the present system is suited for a black and white image being projected using a film based means of projection.
The shutter cycle detection means may be a method of mechanically detecting the frame forwarding; a method of electronically detecting the frame forwarding based on, for example, a change in an electrostatic capacitance; a method of mechanical detection based on an operation of a shutter mechanism; a method of electronic detection based on the operation of the shutter mechanism; or a method of optical detection based on the operation of the shutter mechanism.
The means of calculation calculates an average luminance for the previous frame and the ensuing frame and factors in the human contrast sensitivity increment threshold, in order to determine the luminance of the white color light for the interference that is to be radiated. The control means controls the periods of emission based on the detection results from the shutter cycle detection means. A computer, an application specific semiconductor device, or other electronic circuits may, for example, be used as the means of calculation or as the means of control. This means may be realized by hardware or by software.
(22) A system for interfering against image capturing is proposed for an image being presented on a screen by a projection method using a film based means of projection. The image capturing interference system includes a visible light radiation means for radiating a visible light for the interference onto the screen; a shutter cycle detection means for detecting the time periods during which a frame forwarding shutter shutters the projection light; a means of calculation for determining a luminance and chromaticity of the visible light for the interference based on an average luminance and average chromaticity in a previous frame and an ensuing frame in the target image pixels; and a means of control for projecting the visible light for the interference onto the target image pixels during the time period in which the projection light is shuttered. The present system represents an application example for the method described in (7). The various means described in (21) are used in the present system. Of course, the means of calculation requires a different structure for calculating the average luminance and the average chromaticity.
(23) A system for interfering against image capturing is proposed, that includes a means of radiating a visible light for the interference on to a screen, a means of driving the radiation direction for driving the means of radiating the visible light and changing the direction of radiation; a means of storage for storing information on the directions of radiation for the means of radiating the visible light in response to a screen size; and a means of radiation direction control for reading out the appropriate information on the direction of radiation from the means of storage and providing the information to the means of driving the radiation direction, when an instruction for changing the screen size is detected, and for automatically adjusting the directions of radiation of the visible light for the interference, which is emitted from the means of radiating the visible light. The present system represents an application example for the method described in (8).
The screen size (or the aspect ratio) may be standard (1:1.33), Europe Vista (1:1.66), America Vista (1:1.85), scope (1:2.35), or others. The numeric values mentioned are examples of representative values and are not limited to these values.
The means of driving the radiation direction may include, for example, a means of turning the means of visible light radiation around an attachment axis; a means of rotating or moving horizontally a platform on which the means of visible light radiation is secured; and other means. The information on the directions of radiation, which is stored in the means of storage, may include, for example, a horizontal angle, a vertical angle, or other information. Of course, control values, such as the amount of displacement, may also be included, as well as the angles. As the means of controlling the radiation directions, for example, a computer, an application specific semiconductor device, or other electronic circuits may be used.
(24) A system for interfering against image capturing is proposed in which a visible light for the interference passes through a space outside of the screen and is directly radiated on the viewer. This system represents an application example for the method described in (9). For this reason, the descriptions in (9) may apply on the present system. Since the visible light for the interference is required to pass through a space outside of the screen, the position of the visible light radiation apparatus, which radiates the visible light for the interference, can be at any location. For example, the location may be behind the screen, or the location may in front of the screen. Of course, the location may also be around the screen.
(25) A system for interfering against image capturing is proposed, which radiates a visible light for the interference from a means of radiating the visible light at the back side of a screen and transmits the visible light for the interference through the screen toward the viewer. The present system represents an application example for the method described in (10). Several forms of transmission are possible, depending on the material and structure of the screen.
(26) A system for interfering against image capturing is proposed in which a visible light for the interference, which is radiated by a means of radiating the visible light at the backside of the screen, passes through a passing part in the screen toward the viewer. The present system represents an application example of the method described in (11). In this instance also, several forms of the passing parts of various shapes and structure are possible.
(27) A system for interfering against image capturing is proposed in which a visible light for the interference is emitted by a means of radiating the visible light, which is embedded inside a screen, toward the viewer from the screen surface. The present system represents an application example for the method described in (12). The method of embedding and the forms of the output for the visible light for the interference are similar to the description in (12).
(28) A system for interfering against image capturing is proposed, that includes a plurality of units of means of radiating the visible light, and a means of control for the means of radiating the visible light provides as an output the visible lights for the interference in prescribed combinations at a plurality of locations on the screen, so that a two dimensional optical image pattern may be simultaneously recorded, when an image on the screen is illegally image captured. The present system is an application example for the description in (13). The conditions and the structures required for the basic configurations for the various means are similar to (20).
(29) A system for interfering against image capturing is proposed when an image being presented on a screen by a projection method using a film based means of projection. The image capturing interference system includes a means of radiating a visible light for radiating a white color light for the interference from target image pixels on the screen; a shutter cycle detection means for detecting the time periods during which a frame forwarding shutter shutters the projected light; a means of calculation for determining a luminance of the white color light for the interference based on an average luminance in a previous frame and an ensuing frame in the target image pixels; and a means of control for projecting the white color light for the interference from the target image pixels during the time period in which the projection light is shuttered. The present system is an application example for the description in (14).
The same means of detecting the shuttered cycles, the means of calculation, and the means of control as those in (21), respectively, may be used. The only difference from (21) is the method of radiating the white color light for the interference.
(30) A system for interfering against image capturing is proposed when an image being presented on a screen by a projection method using a film based means of projection. The image capturing interference system includes a means of radiating the visible light for radiating a visible light for the interference from target pixels on the screen; a shutter cycle detection means for detecting the time periods during which a frame forwarding shutter shutters the projection light; a means of calculation for determining a luminance and a chromaticity of the visible light for the interference based on an average luminance and an average chromaticity in a previous frame and an ensuing frame in the target image pixels; and a means of control for projecting the visible light for the interference from the target image pixels during the time period in which the projection light is shuttered. The present system is an application example for the method described in (15).
The same means of detecting the shuttered periods, the means of calculation, and the means of control as those in (22), respectively, may be used. The only difference from (22) is the method of radiating the white color light for the interference.
Specific embodiments for the methods and systems for interfering against image capturing, that are proposed in the present specification, will be described next.
The first embodiment is shown in
A projector apparatus 33 is a projection apparatus for projecting an image to be viewed onto a screen 34. The projector apparatus 33 may be, for example, a film projector for projecting a movie film; a slide projector for projecting a slide; an overhead projector (OHP); a liquid crystal projector that directly projects a digital image; a digital micromirror device (DMD) projector; a CRT projector, or others.
In
The screen 34 in
The visible light radiation apparatus 35 for the interference is an apparatus for radiating a visible light, that satisfies the condition 1 and the condition 2, in order to interfere against an illegal image capturing of the image projected on to the screen. The radiation apparatuses, having the structure shown in, for example,
In the figure, the visible light, radiating from the visible light radiation apparatus 35, is directly radiated on the screen surface. However, an optical beam, that is reflected off a reflective mirror, may also be projected on to prescribed areas on the screen. A higher degree of freedom is allowed for the position of the visible light radiation apparatus 35, when the optical path for the visible light is bent using a reflection mirror. Or, the visible light radiation apparatus 35 itself may be driven for directing the radiation of the visible light toward a prescribed area or space.
By the way, it is also possible to use the plurality of optical image patterns, that are projected onto the screen, in order to record prescribed information (for example, the output time and date, the output location, the screen number, the output apparatus, and other information required for identifying the individual making the output and the location of the illegal activity) or text based information (symbols and other recognizable geometrical information). In such an instance, in general, a plurality of units of the visible light radiation apparatus 35 are collectively operated. When such a function is to be implemented, a means of table (a means of storage) may be used for storing the correlation between the optical image patterns for showing the desired information and the plurality of visible light radiation apparatuses, which generate them.
The visible light that provides the information may, in general, be emitted continuously (turning light on), but the prescribed information may also be provided using a method of emitting the visible light intermittently.
In addition, the method of projecting the visible light includes a method of emitting the visible light intermittently. When the visible light is projected intermittently, the luminance of the image being recorded may change independently of the image being presented and thus degrades the image quality. Furthermore, changes in the intermittent timing and the recorded positions for the optical images may make the desired information be recorded.
The number of the visible light radiation apparatuses 35 is not limited to one unit. Although a single unit of the visible light radiation apparatus 35 is shown in
By radiating the visible light for the interference from the audience toward the screen according to the present embodiment, it is possible to make the desired information on, for example, the location the image capturing be recorded simultaneously with the image that has been illegally captured. Accordingly, the image quality can also be made to degrade. As a result, an interference effect comparable to but not using an infrared light can be achieved.
The screen 34 is a screen for a theater. In general, holes for sound sources (through holes that communicate between the back side and the front side or other structures), which are called sound perforation, are formed in order to efficiently transmit the sound from sources of the sound, which are placed behind the screen, toward the audience. Any shapes, sizes, and locations may be allowed for the sound perforation. In the specification of the present application, the sound perforation is used as passing parts for allowing the visible light for the interference to pass from behind the screen to the front of the screen.
By the way, the screen 34 in
The visible light radiation apparatus 35 is an apparatus for radiating the visible light for interfering against an illegal image capturing of the image that is projected onto the screen. By the way, an internal configuration of the visible light radiation apparatus 35 is the same as in the first embodiment.
The visible light radiation apparatus 35 is, in general, located near the back side of the screen. However, any location may be allowed, as long as the location is behind a hypothetical reference surface, which includes the screen surface, with respect to the seats 36. For example, the visible light radiation apparatus 35 may be placed behind the screen 34 at an angle. By the way, the point of emission may be in contact with the screen, or the point of emission may be embedded into the screen. The point of emission, that is embedded into the screen, may be exposed at the surface of the screen toward the front.
In the figure, the visible light that is radiated from the visible light radiation apparatus 35 is directly radiated on to the screen surface. However, as shown in
Even in such an instance, prescribed information or text information may be recorded using a plurality of optical image patterns projected onto the screen. Normally, a plurality of units of the visible light radiation apparatus 35 are collectively operated. In order to realize this feature, a means of table (means of storage) is used for storing relationships of correlation between the optical image patterns, that represent the desired information, and the plurality of units of the visible light radiation apparatus that generate them.
In general, the visible light that provides this information is lit on continuously (turning light on), but it is also possible to present the prescribed image using a method of intermittently emitting the visible light.
Furthermore, the method of projecting the visible light includes a method of intermittently emitting the visible light. When the visible light is projected intermittently, the luminance of the image being recorded changes independently of the image being presented and thus degrades the quality of the image. By the way, a recording of desired information can also be facilitated by making the timings of intermittence and the recording positions of the optical images variable.
The number of units of the visible light radiation apparatus 35 is not limited to a single unit. Although a single unit of the visible light radiation apparatus 35 is shown in
By radiating the visible light for the interference onto the screen from behind the screen, as in the present embodiment, it is possible to have the desired information, that shows, for example, the location of the image capturing, be recorded in the image that has been captured illegally. Accordingly, it is also possible to degrade the quality of the image. As a result, it is possible to realize an interference effect similar to but not using the infrared light.
Next, specific examples of the various apparatuses, that make up the system shown in
The visible light radiation apparatus 35 has a similar apparatus configuration as the previous embodiment. The position of and a projection method used for the visible light radiation apparatus 35 are different. By the way, the visible light being radiated from a position outside of the screen, as in the present embodiment, is required to satisfy the condition 1 and condition 2 with respect to a background light, so that the visible light for the interference may not be detected during a normal viewing.
The position of the visible light radiation apparatus 35 is usually near an outer edge of the screen. The closer it is to an area, onto which the image being presented is projected, the more likely the visible light, that is being projected, may be recorded, because the visible light may be within a field of image capturing, be recorded directly, and more likely affect the field of image capturing. A more significant interference effect is thus achieved. However, the interference effect may not necessarily be less significant in a position that is further outside of the edge of the screen.
In such an instance, a means of reflection may be used to bend the optical path for the visible light for the interference. When a reflection mirror is used for bending the optical path for the visible light, a higher degree of freedom is allowed for the position of the visible light radiation apparatus 35. Furthermore, as described earlier, instead of reflecting the visible light through a means of reflection, the visible light radiation apparatus 35 itself may be driven to direct the radiation of the visible light toward the above-mentioned prescribed area or space.
The visible light that provides this information is, in general, emitted continuously (turning light on). However, a prescribed information may also be provided by a method of emission, in which the visible light is emitted intermittently.
In addition, the method of projecting the visible light includes a method of emitting the visible light intermittently. When the visible light is projected intermittently, the luminance of the image being recorded may change independently of the image being presented and thus degrade the quality of the image. By the way, desired information can be made to be recorded by making the timings of intermittence and the recording positions of the optical images variable.
Furthermore, the number of the visible light radiation apparatus 35 is not limited to a single unit. While
When the visible light for the interference passes through a space outside of the screen and is radiated toward the audience, as in the present embodiment, it is possible to have the desired information, that shows, for example, the location of the image capturing, be recorded into the image that has been illegally captured. Of course, it is also possible to degrade the quality of the image. As a result, an interference effect similar to but not using the infrared light can be realized.
Next, specific examples of various apparatuses, that make up the system shown in
In the present embodiment, a surface of the screen is divided into 28 virtual partial areas, which make up four columns and seven rows. One unit of the visible light radiation apparatus 35 is placed for each partial area.
A shutter sensor 38 is effective in a film based projector apparatus, which is used as a projector apparatus 33. Therefore, this type of shutter sensor 38 may not exist in the projector apparatus 33 that is based on a digital signal format. The shutter sensor 38 is used for projecting the visible light for the interference onto the screen during the time period, in which the shutter 42 in the film based projector apparatus (i.e. a movie projector) shutters the projection light.
In general, the shutter 42 for shuttering the optical source light is a disc with slits. Normally, the slits are formed at two symmetrical positions on the disc. Normally, the disc rotates 24 times in each second and shuts out the optical source light twice for each frame (
By the way, the luminance and chromaticity of the visible light being radiated satisfy the condition 1 and the condition 2 with respect to a background light, which is assumed to have an average luminance and an average chromaticity between a previous frame and an ensuing frame. For this reason, the visible light may have a luminance of a value between 0% and 100%.
The shutter sensor 38 may operate based on an optical method, as well as an electronic method or a mechanical method. For example, a method shown in
When the method shown in
Furthermore, the optical based method also includes a method in which the light emitting diode and the photo diode are placed in such a way as to face each other while sandwiching the rotating area of the disc, and the relative position of the shutter 42 (rotation position) is detected based on whether or not a beam of light radiating from the light emitting diode is received by the photo diode. In this instance, the rotation position of the disc can be detected based on the timings with which the light, which emits from the light emitting diode, is received by the photo diode or shuttered from the photo diode.
In addition, the shutter sensor 38 may rely on a method of mechanically detecting the rotational position of the disc. For example, the rotational position of the shutter may be mechanically detected based on the rotational position of a gear (the position of teeth), which is attached coaxially with respect to the rotation axis. In yet another example, electrodes may be installed, with the rotating area of the disc sandwiched in between, and the detection method may be based on measuring the changes in the static capacitance between the electrodes in order to detect whether a blade in the disc or a gap is between the electrodes. Furthermore, another method is possible in which the rotational position of the shutter is detected based on the information related to the drive of the rotation axis.
Furthermore, it goes without saying that, when the shape of the shutter varies or the method of the shutter varies, an appropriate form of the shutter sensor 38 may be used in response to the shapes or the forms. For example, when the opening and closing of the shutter is controlled electronically, then the periods, during which the optical source light is shuttered, may be detected based on a method that relies on the signals for the opening and the closing.
A method of using a detection result may include a method in which an infrared light is emitted, when a closing of the shutter is detected, or a method in which the closing of the shutter is predicted based on the detected results, and the infrared light is emitted based on a predicted timing.
The visible light radiation control apparatus 39 is a means of controlling the light emitted by the visible light radiation apparatus 35 based on the shutter information S1, which is received from the shutter sensor 38. In the present embodiment, a process of determining the luminance and the chromaticity of the visible light being radiated is executed by the visible light radiation apparatus 35. It is also possible, by the way, to have the visible light radiation control apparatus 39 execute the process of determining the chromaticity and the luminance.
The internal configuration of the visible light radiation control apparatus 39 varies in response to the application system. For example, as shown in
For example, a desired interference effect may be realized, without using a control apparatus, by simply using the detection results from the shutter sensor 38 as a control signal for turning on or off the visible light radiation apparatus 35.
Returning to the instance in which the visible light radiation control apparatus 39 is used. For example, when the shutter sensor 38 detects a closing of the shutter (or the projection light being shuttered), the visible light radiation control apparatus 39 may provide a control signal S2, as an output to send an instruction to the visible light radiation apparatus 35 to radiate the visible light. In this instance, the visible light radiation control apparatus 39 may instruct all of the visible light radiation apparatuses to radiate the visible light (in the example in
An effect similar to superimposing the visible light for the interference onto the image being projected can also be realized by the visible light for the interference, including the white color light, that is emitted only during the periods of frame forwarding, as in the present embodiment.
In
A program server 45 is an apparatus for feeding out the image data S3 to the projector apparatus 33. The image data S3 may include data read out from a recording medium 46 (which may include, for example, a videotape, a CD-ROM, a DVD, etc.) as well as data received through a network 47. Such an output of the image data S3 may not take place, however, when the projector apparatus 33 is a film based projector apparatus.
The program server 45 reads out the information related to the timing or the information related to the positions of partial areas, on which the visible light radiation may be applied, by functioning as an apparatus for reproducing information from the recording medium 46 or by functioning as an apparatus for receiving data from the network 47. In other words, the program server 45 also functions as an apparatus for feeding out the visible light radiation control data S4 into the visible light radiation control apparatus 39. By the way, the recording medium may be those provided through a postal service or a home delivery service or a recording of the data received in advance through a distribution over the network 47. Furthermore, the visible light radiation control data S4 may include information related to the relationships between the chromaticity and the luminance of the visible light.
In this instance, the image data S3, which is fed to the projector apparatus 33, and the visible light radiation control data S4, which is fed to the visible light radiation control apparatus 39, are synchronized by the program server 45. Of course, the synchronization of the data is controlled based on a common synchronization data or information related to the timing of the data reproduction in a digital format projection system. By the way, the timing of the output for the visible light radiation control data S4 is controlled based on synchronization signals and information related to positions, which are read from a film, as well as information related to the rotational position of the shutter 42, if the projector apparatus 33 is film based.
The visible light radiation control apparatus 39 is a means of actually controlling the emission of light from the visible light radiation apparatus 35. Similar to the sixth embodiment, the visible light radiation control apparatus 39 may instruct all units of the visible light radiation apparatuses 35 to radiate the visible light or provide instructions to only some of the visible light radiation apparatuses 35 to radiate the visible light.
An effect similar to the previous embodiments is realized by controlling the emission of the visible light for the interference using data read from a recording medium or data received through a network, as in the present embodiment.
Firstly, the method of positioning the visible light radiation apparatus 35 will be described. In
In
The apparatuses that are characteristic to the system shown in
The means of drive, however, is not limited to a method in which a force is transmitted based on an amount of rotation and may include a method in which a force is transmitted based on an amount of displacement in a linear direction. Furthermore, the means of drive may be applied directly on the visible light radiation apparatus 35 or applied indirectly through linking devices, which may include gears, rubbers, and others. Furthermore, while the displacement takes place in only one direction in
The screen mask change apparatus 49 is a means of automatically feeding the information related to the drive control for the visible light radiation apparatus to the radiation direction drive apparatus 48 in response to an instruction to change the screen size. For example, the screen mask change apparatus 49 may include a memory unit that stores information (for example, information related to the direction of radiation or angle) that correlates the screen size and the corresponding projection directions for the infrared projection apparatus, and a control unit that reads out appropriate numerical values for the new screen size, when the screen size is changed, from the memory unit, and feeds the information to the radiation direction drive apparatus 48 for the various positions. If the information provided as an output to the radiation direction drive apparatus 48 were not the target values (the optimal values), as in the present example, then the amount of adjustment (a differential value) with respect to the present value, may be calculated and provided. One of these data is provided by the screen mask change apparatus 49 to the radiation direction drive apparatus 48 as the control data S6 output.
By the way, instructions related to changes in the screen size or information on the optimal screen size may, in some cases, be provided in conjunction with a manual operation by an operator or, in other cases, provided automatically based on information recorded in association with the image contents. In a movie theater, for example, the operator at the theater operates buttons for changing the position of the mask, when the screen size, or the aspect ratio, changes. The same button operation may also be used for manipulating a change in the direction of the projection. Or, as in the latter case, in which the recorded information is to be used, the optimization information may be recorded either in the media itself, that stores the image contents, or in another recording medium, that is separate from the image contents, in a form of a mapping table.
While in
By automatically adjusting the direction of the projection for the visible light in response to the screen size, as in the present embodiment, it is possible to avoid the projection positions of the visible light and the image contents from being out of synchronicity. By the way, a similar effect can be realized by controlling the luminance information and the chromaticity information for the visible light, that is fed to the visible light radiation apparatus, instead of controlling the direction of projection for the visible light.
In the various embodiments described above, representative and specific examples of the conceptual embodiments are reviewed. Systems that combine the various embodiments described above or other examples of variation are also possible.
By using the visible light that satisfies the condition 1 and the condition 2, as mentioned above, it is possible to make an optical image, that is unrelated to the image being presented, be superimposed with and recorded in an illegally captured version of the image on the screen, although the optical image may not be visible to the audience in the normal viewing. As a result, it is possible to interfere against an illegal image capturing activity.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2001-244712 | Aug 2001 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP02/07965 | 8/5/2002 | WO | 00 | 9/22/2003 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO03/016997 | 2/27/2003 | WO | A |
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| 20040109562 A1 | Jun 2004 | US |
