Patent Application
20070103598
The present invention relates to a video signal processing device for executing an image conversion to a digitalized video signal.
There is available a video format conversion in which a projected image taken in a film, such as a movie, and a video signal produced in a CCD device for taking an image based on number of frames (24 frames per second) equal to that of the projected image taken in the film can be displayed on an NTSC TV receiver or recorded in a recording device such as VCR (Video Cassette Recorder). Well-known examples of the video format conversion are the 2:3 pull-down method and the 2:3:3:2 pull-down method. As a known conventional example of the video format conversion of the pull-down method recited in No. 2003-284007 of the Publication of the Unexamined Japanese Patent Applications, the format conversion is executed in synchronous systems on input and output sides independent from each other so as to improve a visibility of the projected image after the format conversion.
As a result of applying the foregoing video format conversion, a progressive video signal comprising 24 frames per second (hereinafter, referred to as 24P video signal) can be accurately converted into an interlace video signal (hereinafter, referred to as 60I video signal) comprising 60 fields per second in the NTSC TV receiver, VCR and the like. Thereby, even the 60I video signal is able to achieve visual effects that are generally obtained in the movie film (24P video signal).
An example of the image conversion of the 2:3:3:2 pull-down method is described referring to
First, the 24P video signal inputted to the input terminal 71 is written in the respective frame memories 74 and 75. In the writing process, the write/read controller 76 switches from one of the memories to the other (frame memories 74 and 75) per frame of the 24P video signal in accordance with the frame synchronous signal of the 24P video signal inputted to the input terminal 72. The pull-down controller 78 executes a read control with respect to the frame memories 74 and 75 using the write/read controller 76 based on the frame synchronous signal of the 60I video signal inputted to the input terminal 73. The pull-down controller 78 outputs the video signals read from the frame memories 74 and 75 through selection of the signals in the memory selector 77. The video signal converted into the 60I video signal is outputted from the memory selector 77 via the output terminal 79.
Below is given a more detailed description. In a 24P input video signal 82 shown in
First, the 24P input video signal 82 is written in the frame memories 74 and 75 based on the frame synchronous signal 81. In other words, the write control signal 83 of the frame memory 74 and the write control signal 84 of the frame memory 75 are generated based on the frame synchronous signal 81. Then, the 24P input video signal 82 is written in the frame memory 74 based on the write control signal 83 when the frame synchronous signal 81 of the 24P video signal is HIGH. In contrast, the 24P input video signal 82 is written in the frame memory 75 based on the write control signal 84 when the frame synchronous signal 81 of the 24P video signal is LOW.
Next, the video signals stored in the frame memories 74 and 75 are serially read out as follows so that the 60I video signal 86 is generated. More specifically, in a first frame of the 60I video signal 86, a frame A of the 24P input video signal 82 is divided into a field Ao consisting of odd-numbered lines and a field Ae consisting of even-numbered lines, and the fields Ao and Ae as the dividing result are read as the first frame of the 60I video signal 86.
In the same manner, in a second frame of the 60I video signal 86, a frame B of the 24P input video signal 82 is divided into a field Bo consisting of odd-numbered lines and a field Be consisting of even-numbered lines, and the fields Bo and Be as the dividing result are read as the second frame of the 60I video signal 86.
In a third frame of the 60I video signal 86, the frame B of the 24P input video signal 82 is divided into the field Bo consisting of odd-numbered lines and the field Be consisting of even-numbered lines, and a frame C of the 24P input video signal 82 is divided into a field Co consisting of odd-numbered lines and a field Ce consisting of even-numbered lines. Then, the divided field Bo and the field Ce constitute a frame, which is read as the third frame of the 60I video signal 86.
In a fourth frame of the 60I video signal 86, the frame C of the 24P input video signal 82 is divided into the field Co consisting of odd-numbered lines and the field Ce consisting of even-numbered lines, and the fields Co and Ce as the dividing result are read as the fourth frame of the 60I video signal 86.
In a fifth frame of the 60I video signal 86, a frame D of the 24P input video signal 82 is divided into a field DO consisting of odd-numbered lines and a field De consisting of even-numbered lines, and the fields Do and De as the dividing result are read as the fifth frame of the 60I video signal 86.
The respective frames of the 24P video signal are thus divided into the fields and read. Then, the fields of the frames are serially read in a partially overlapping manner based on such a repeated cycle as the two fields (Ao:Ae)→three fields (Bo:Be:Bo)→three fields (Ce:Co:Ce)→two fields (Do:De)→ . . . (hereinafter, referred to as 2:3:3:2 cycle), so that the 24P video signal is converted into the 60I video signal.
In the device constitution shown in
The respective frames of the 24P video signal may be serially read based on such a repeated cycle as two fields→three fields→two fields→three fields→ . . . (hereinafter, referred to as 2:3 cycle) in the 60I video signal and thereby converted into the 60I video signal. Such a conversion method is called the 2:3 pull-down method.
The conventional constitution involves the following problems. The 24P video signal is a video format generally used in movie films. The 60I video signal is an example of a standard video format in television broadcasts. Therefore, when the 24P video signal is converted into the 60I video signal by means of the conversion format of the 2:3 pull-down method or the like, visual effects that are obtained in the movie films can be obtained in the same manner in the standard image display in the television broadcasts.
Recently, there is a strong demand that visual effects equal to those that are generally obtained in the movie films be realized in a video system or the like handled by an amateur video producer. In order to realize the foregoing visual effects in the in the generally employed format such as the 60I video signal, the 24P video signal is indispensable as an image source to be inputted. However, the 24P video signal cannot be obtained without video data taken and recorded in the film per se, or an image pickup device capable of taking the 24P video signal.
In the format conversion, such as the 2:3:3:2 pull-down method, which is executed in order to convert the 24P video signal into the 60I video signal, two frame memories are required as the indispensable components in such a conversion device. Further, the write/read control with respect to the frame memories, particularly the read control becomes complicated, and it becomes necessary to control the timing (frame synchronization) in the conversion of the 24P video signal into the 60I video signal. Thus, the formation conversion involves such unfavorable aspects as an increased circuit size, cost increase and more complicated controls.
Therefore, a main object of the present invention is to provide a video signal processing device capable of displaying a projected image achieving such visual effects that are obtained in the film in the NTSC receiver and VCR without any visual problem by means of a simplified circuit constitution and control method in the absence of the projected image taken in the film and the video signal generated by the image pickup device for picking up the image based on the number of the frames equal to that of the projected image taken in the film.
A video signal processing device according to the present invention comprises a gain controller for gain-controlling a digitalized video signal per minimum video unit thereof and a variation controller for setting video blocks each comprising a plurality of minimum video units and setting a gain control value of the gain controller in each of the minimum video units constituting the set video blocks.
The gain controller serially divides the video signals into the video blocks, and gain-controls the respective minimum video units constituting the respective video blocks resulting from the division based on the gain control values.
According to the present invention, the video signals are serially divided into the respective video blocks, and the minimum video units constituting the respective video blocks resulting from the division are gain-controlled based on the gain control value, so that visual effects equal to those obtained in an input source can be realized in the video signal in a pseudo manner. Thereby, the present invention can generate the video signal capable of displaying the same visual effects as obtained in the film or the like in the pseudo manner in an NTSC receiver and VCR without any visual problem. Further, the present invention can attain such an effect in a simplified circuit configuration and control method.
Hereinafter, preferred embodiments of the present invention are described in detail referring to the drawings.
Prior to the description of the preferred embodiments is described visual effects of a 24P video signal. In a 60I video signal, which is an exemplary standard video format in television broadcasts, moving images each divided into 30 frames per second are continuously displayed in such a manner that each frame is further divided into two fields. Since a large number of moving images are continuously displayed, a viewer can hardly visually recognize flickers on the displayed image due to his/her capacity for visual perception.
In the case of the 24P video signal, moving images divided into 24 frames per second, which are less than 30 frames, are continuously displayed in such a manner that each frame is directly displayed as frame without the division into the frames. Therefore, when the 24P video signal is displayed, the viewer more easily visually recognizes the flickers on the displayed image than in the case of the 60I video signal. A cycle in which the visually recognized flickers are generated corresponds to a frame period ( 1/24 second) of the 24P video signal. Even if the 24P video signal is converted into the 60I video signal, such flickers are still visually recognized in the 60I video signal resulting from the conversion. Further, the cycle in which the visually recognized flickers are generated corresponds to 1/24 second in the same manner as the generation cycle of the flickers in the 24P video signal before conversion.
The visual effects obtained in the 24P video signal result from the flickers, and the visual effects are emphasized since the flickers are generated based on the same cycle as the frame period of the 24P video signal ( 1/24 second).
Based on the observation, the present invention intentionally generates the flickers in the 60I video signal based on the substantially same cycle as the frame rate of the 24P video signal in view of the foregoing observation. Thereby, the 60I video signal, which does not result from the conversion from the 24P video signal and therefore lacks the foregoing visual effects (flickers), is vested with the visual effects in a pseudo manner.
Referring to reference numerals shown in
In the video signal processing device, first, the digitalized 60I input video signal 22 is inputted from the input terminal 11 to the gain controller 14, and the frame synchronous signal 21 of the 60I video signal 22 is inputted from the input terminal 12 to the variation controller 13. The 60I input video signal 22 inputted to the input terminal 11 and the frame synchronous signal 21 inputted to the input terminal 12 synchronize with each other as shown in
The variation controller 13 sets a gain control value of the gain controller 14 based on the frame synchronous signal of the 60I video signal. More specifically, the variation controller 13 handles five fields (in the case of the 2:3 pull-down method) or ten fields (in the case of the 2:3:3:2 pull-down method), which are continuous in the inputted 60I input video signal 22, as one video block, and sets the gain control value so that the gain control value changes per field in each video block. In
First, a control operation in the case of generating in the pseudo manner the visual effects generated in displaying a film image at an image conversion cycle according to the 2:3 pull-down method is described referring to
As shown in the control value (gain) 23 in
The variation controller 13 sets the gain control value by repeating the foregoing control routine. Below is given a more detailed description.
A correspondence relation between the count value of the cyclic counter 13a and the gain adjustment amount of the gain controller 14 is previously set based on the setting of the minimum video unit groups A11 and A12. The variation controller 13 memorizes the correspondence relation between the set gain adjustment amount and count value (minimum video unit groups A11 and A12). In the case of adjusting the luminance in accordance with the 2:3 pull-down method, the correspondence relation memorized by the variation controller 13 is as follows. In the case of the minimum video unit groups A11 showing count values (1) and (2), the variation controller 13 sets the gain adjustment amount of 1.0 times. In the case of the minimum video unit groups A12 showing count values (3), (4) and (5), the variation controller 13 sets the gain adjustment amount of 0.9 times. The control routine is repeated so that the gain adjustment amounts are set.
The gain controller 14 actually controls the gain in accordance with the gain control value set by the variation controller 13. More specifically, the gain controller 14 multiplies the luminance signal of the 60I input video signal 22 inputted from the input terminal 11 for the 60I video signal by the set gain control value to thereby change the gain of the video signal. Thus, the gain of the luminance signal is controlled for every two fields and three fields (see
Next is described a control operation in the case of generating in the pseudo manner the film image effects based on an image conversion cycle according to the 2:3:3:2 pull-down method referring to
As shown in the control value (gain) 33 shown in
Because the gain control value is differently set in the minimum video unit groups A21 and A22, the variation controller 13 is constituted as follows. The variation controller comprises a cyclic counter 13a for repeatedly counting the ten fields of 1-10. The cyclic counter 13a repeatedly provides count values of (1)-(10) for the respective fields constituting the 60I input vide signal 22. The variation controller 13 recognizes the respective video blocks A2 based on the count values counted up by the cyclic counter 13a and determines the field positions in the respective video blocks A2. The variation controller 13 judges if the relevant field is included in the minimum video unit group A2, or in the minimum video unit group A22 based on the determined field positions, and sets the gain control value based on a result of the determination.
The variation controller 13 sets the gain control value by repeating the foregoing control routine. Below is given a more detailed description.
A correspondence relation between the count value of the cyclic counter 13a and the gain adjustment amount of the gain controller 14 is previously set based on the setting of the minimum video unit groups A21 and A22. The variation controller 13 memorizes the correspondence relation between the set gain adjustment amount and count value (minimum video unit groups A21 and A22). In the case of adjusting the luminance in accordance with the 2:3:3:2 pull-down method, the correspondence relation memorized by the variation controller 13 is as follows. In the case of the minimum video unit groups A21 showing count values (1), (2), (6), (7) and (8), the variation controller 13 sets the gain adjustment amount of 1.0 times. In the case of the minimum video unit groups A22 showing count values (3), (4), (5), (9) and (10), the variation controller 13 sets the gain adjustment amount of 0.9 times. The control routine is repeated so that the gain adjustment amounts are set.
The gain controller 14 actually controls the gain in accordance with the gain control value set by the variation controller 13. More specifically, the gain controller 14 multiplies the luminance signal of the 60I input video signal 32 inputted from the input terminal 11 for the 60I video signal by the set gain control value to thereby change the gain of the video signal. Thus, the gain of the luminance signal is controlled for every two fields, three fields, three fields and two fields (see
When one of the two luminance adjustments described above is executed, the gain of the luminance signal is changed 24 times per second. As a result, the flickers are generated as the visual effects in the 60I output video signal based on the cycle of 1/24 second. The video signal processing device according to the present invention generates the flickers in accordance with the 2:3 pull-down cycle or the 2:3:3:2 pull-down cycle.
Thereby, even when the input video signal is 60I video signal, the output video signal thereof (60I video signal) can be easily provided with the film image effects (flickers generated based on the cycle of 1/24 second). The visual effects mentioned here are, as described earlier, such visual effects that can be visually recognized by a viewer when the 24P video signal is displayed and still remain when the 24P video signal is converted into the 60I video signal.
The video signal processing device according to the present invention realizes the visual effects without providing a plurality of field memories and by executing such a relatively simple control operation as adjusting the gain in accordance with the counted number of the fields.
When the luminance (gain) is adjusted based on the cycles of the 2:3 pull-down method and the 2:3:3:2 pull-down method, it is unavoidable for the variation points of the luminance (gain) to be located across the frames of the 60 video signal. For example, in the 2:3 pull-down cycle shown in
Below is described a control operation in order to eliminate the variation points of the luminance (gain) at such positions that may generate the visual problem. As shown in
In the case of executing the described gain control, the cycle in which the luminance (gain) is changed (cycle in which the flickers are generated) is 1/30 second, and such visual effects that can be obtained when the film image of 30 frames per second is viewed, which are similar to those according to the present embodiment, can be obtained. However, the obtained cycle is slightly shorter than 1/24 second, which is the originally desired cycle in which the luminance (gain) is changed. Because a difference between the two cycles is relatively small despite the disadvantage, the foregoing control operation may be executed when it is the highest priority to eliminate the variation points of the luminance at such positions that may generate the visual problem.
In the foregoing control operation, the cyclic counterl3a repeatedly provides the count values of (1)-(4) for the respective fields constituting the 60I input video signal 22. The variation controller 13 determines the fields to be controlled (minimum video unit groups A31 and A32) based on the count values counted up by the cyclic counter 13a, and sets the gain control values described above for the determined fields (minimum video unit groups A31 and A32). The variation controller 13 sets the gain control values by repeating the control routine. Below is given a more detailed description.
A correspondence relation between the count value of the cyclic counter 13a and the gain adjustment amount of the gain controller 14 is previously set based on the setting of the minimum video unit groups A31 and A32. The variation controller 13 memorizes the correspondence relation between the set gain adjustment amount and count value (minimum video unit groups A31 and A32). In the case of adjusting the luminance in such a manner that the flickers are generated based on the cycle of 1/30 second, the correspondence relation memorized by the variation controller 13 is as follows. In the case of the minimum video unit groups A31 showing count values (1) and (2), the variation controller 13 sets the gain adjustment amount of 1.0 times. In the case of the minimum video unit groups A32 showing count values (3) and (4), the variation controller 13 sets the gain adjustment amount of 0.9 times. The control routine is repeated so that the gain adjustment amounts are set. The gain controller 14 actually controls the gain in accordance with the gain control value set by the variation controller 13. More specifically, the gain controller 14 multiplies the luminance signal of the 60I input video signal 320 inputted from the input terminal 11 for the 60I video signal by the set gain control value to thereby change the gain of the video signal. Thus, the gain of the luminance signal is controlled for every two fields and two fields (see
Referring to reference numerals shown in
Referring to reference numerals shown in
Referring to reference numerals shown in
Below is described a control operation by the video signal processing device. First, a control operation for vesting the 60I video signal with the film image effects based on the 2:3 pull-down cycle in the pseudo manner is described referring to
In the video signal processing device, the digitalized 60I input video signal 52 is inputted from the input terminal 41 to the field memory 43 and the selector 44, and the frame synchronous signal 51 of the 60I input video signal 52 is inputted from the input terminal 42. The 60I input video signal 52 inputted to the input terminal 41 and the frame synchronous signal 51 inputted to the input terminal 42 synchronize with each other as shown in
The frame synchronous signal 51 of the 60I input video signal 52 is inputted to the memory controller 45 and the variation controller 47. The memory controller 45 and the variation controller 47 execute their control operations based on the frame synchronous signal.
The selector 44 alternatively selects the 60I input video signal 52 inputted via the input terminal 41 or the output read from the field memory 43 and outputs the selection result. The memory controller 45 controls the write and the read with respect to the field memory 43. The memory controller 45 controls the selecting operation of the selector 44.
The memory controller 45 more specifically controls the selecting operation as follows. The memory controller 45 comprises a cyclic counter 45a for repeatedly counting five fields of 1-5. The cyclic counter 45a repeatedly provides the count values of 1-5 for respective fields constituting the 60I input video signal 52 inputted to the input terminal 41 for the 60I video signal.
The count values of the cyclic counter 45a showing the fields to be written in the field memory 43 are previously set, and the memory controller 45 memorizes the set count values to be written. In the case of attaining the film image effects based on the 2:3 pull-down cycle in the pseudo manner, the count values to be written are (1) and (3).
The memory controller 45 outputs an instruction for writing the 60I input video signal 52 to the field memory 43 at such a timing that the count value of the 60I input video signal 52 supplied by the cyclic counter 45a is a count value showing the field to be written. The instruction for writing the 60I input video signal 52 is supplied to the field memory 43 as the write control signal 53 with respect to the field memory shown in
The count values of the cyclic counter 45a showing timings of the read operation with respect to the field memory 43 are previously set, and the memory controller 45 memorizes the set count values showing the timings of the read operation. In the case of imparting the film image effects based on the 2:3 pull-down cycle in the pseudo manner, the count values showing the timings of the read-operation are (2), (4) and (5).
The memory controller 45 outputs an instruction for the read operation to the field memory 43 at such a timing that the count value supplied by the cyclic counter 45a is a count value showing the timing of the read operation. The instruction for the read operation is supplied to the field memory 43 as the read control signal 54 with respect to the field memory shown in
In the case of imparting the film image effects based on the 2:3 pull-down cycle in the pseudo manner, the memory controller 45 instructs the write of the 60I input video signal 52 in the field memory 43 at, for example, at such timings that the count value of the cyclic counter 45a shows (1) and (3). At such timings that the count value of the cyclic counter 45a shows (2), (4) and (5), the memory controller 45 instructs the read operation with respect to the field memory 43.
The selection of the output by the selector 44 is controlled by the count value of the cyclic counter 45a. A linkage between the count value of the cyclic counter 45a and the output selection of the selector 44 is previously set, and the memory controller 45 memorizes the set linkage.
The 60I input video signal 52 and the output read from the field memory 43 are inputted to the selector 44. The memory controller 45 controls the selector 44 based on the field count value of the 60I input video signal 52 supplied by the cyclic counter 45a. More specifically, the memory controller 45 controls the selector 44 so that the 60I input video signal 52 and the output read from the field memory 43 are selectively outputted.
In the case of imparting the film image effects based on the 2:3 pull-down cycle in the pseudo manner, the linkage memorized by the selector 44 is as follows. The selector 44 selects the 60I input video signal 52 inputted to the input terminal 41 for the 60I video signal when the count values are (1) and (3), while selecting the output read from the field memory 43 when the count values are (2), (4) and (5).
Therefore, at such timings that the write operation is being executed to the field memory 43 (at such timings that the count value of the cyclic counter 45a shows (1) and (3)), the selector 44 selects the 60I input video signal 52 from the input terminal 41 and outputs it. At such timings by which the read operation is being executed to the field memory 43 (at such timings that the count value of the cyclic counter 45a shows (2), (4) and (5)), the selector 44 selects the output read from the field memory 43 and outputs it. Thereby, the selector 44 repeatedly outputs the 60I video signal already written in the field memory 43 until the write of the next video signal is executed as shown in the video signal 55 outputted from the selector in
The variation controller 47 sets the gain control value with respect to the gain controller 46 based on the frame synchronous signal 51 of the 60I input video signal 52 inputted to the input terminal 42. At the time, the variation controller 47 changes the gain control value per field, and sets the gain control value so that the gain control value is changed when the video signal outputted from the selector 44 is different to the video signal of the field immediately before. Below is given a more detailed description.
In the case of imparting the film image effects based on the 2:3 pull-down cycle in the pseudo manner, the variation controller 47 sets video blocks A4 each comprising five fields.
As shown in the control value (gain) 56 in
The variation controller 47 sets the gain control value by repeating the foregoing control routine. Below is given a more detailed description.
A correspondence relation between the count value of the cyclic counter 45a and the gain adjustment amount of the gain controller 46 is previously set based on the setting of the minimum video unit groups A41 and A42. The variation controller 47 memorizes the correspondence relation between the set gain adjustment amount and count value (minimum video unit groups A41 and A42). In the case of adjusting the luminance in accordance with the 2:3 pull-down method, the correspondence relation memorized by the variation controller 47 is as follows. In the case of the minimum video unit groups A41 showing count values (1) and (2), the variation controller 47 sets the gain adjustment amount of 1.0 times. In the case of the minimum video unit groups A42 showing count values (3), (4) and (5), the variation controller 47 sets the gain adjustment amount of 0.9 times. The foregoing control routine is repeated so that the gain adjustment amounts are set.
The gain controller 46 actually controls the gain in accordance with the gain control value set by the variation controller 47. More specifically, the gain controller 46 multiplies the luminance signal of the 60I input video signal 22 outputted from the selector 44 by the set gain control value to thereby change the gain of the video signal. Thus, the gain of the luminance signal is controlled for every two fields and three fields corresponding to the 2:3 pull-down cycle.
Next is described a control operation in the case of generating in the pseudo manner the film image effects based on the 2:3 pull-down cycle referring to
The control operation in the present case is basically the same as in the case of generating in the pseudo manner the film image effects based on the 2:3 pull-down cycle, and the description of any part and control that are the same is omitted.
The cyclic counter 45a of the memory controller 45 repeatedly counts ten fields of 1-10. The cyclic counter 45a repeatedly provides count values of 1-10 for the respective fields constituting the 60I input vide signal 62 inputted to the input terminal 41 for the 60I video signal.
The count values of the cyclic counter 45a showing the fields to be written in the field memory 43 are previously set, and the memory controller 45 memorizes the set count values to be written. In the case of attaining the film image effects based on the 2:3:3:2 pull-down cycle in the pseudo manner, the count values to be written are (1), (3), (6) and (9).
The memory controller 45 outputs the instruction for writing the 60I input video signal 52 to the field memory 43 at such a timing that the count value of the 60I input video signal 52 supplied by the cyclic counter 45a is the count value showing the field to be written. The instruction for writing the 60I input video signal 52 is supplied to the field memory 43 as the write control signal 63 with respect to the field memory shown in
The count values of the cyclic counter 45a showing timings of the read operation with respect to the field memory 43 are previously set, and the memory controller 45 memorizes the set count values showing the timings of the read operation. In the case of imparting the film image effects based on the 2:3:3:2 pull-down cycle in the pseudo manner, the count values showing the timings of the read-operation are (2), (4), (5), (7), (8) and (10).
The memory controller 45 outputs the instruction for the read operation to the field memory 43 at such a timing that the count value supplied by the cyclic counter 45a is the count value showing the timing of the read operation. The instruction for the read operation is supplied to the field memory 43 as the read control signal 64 with respect to the field memory shown in
In the case of imparting the film image effects based on the 2:3:3:2 pull-down cycle in the pseudo manner, for example, at such timings that the count value of the cyclic counter 45a shows (1), (3), (6) and (9), the memory controller 45 instructs the write of the 60I input video signal 62 with respect to the field memory 43. At such timings that the count value of the cyclic counter 45a shows (2), (4), (5), (7), (8) and (10), the memory controller 45 instructs the read operation with respect to the field memory 43.
The output selection by the selector 44 is controlled by the count value of the cyclic counter 45a. A linkage between the count value of the cyclic counter 45a and the output selection of the selector 44 is previously set, and the memory controller 45 memorizes the set linkage.
The 60I input video signal 52 and the output read from the field memory 43 are inputted to the selector 44. The memory controller 45 controls the selector 44 based on the field count value of the 60I input video signal 52 supplied by the cyclic counter 45a. More specifically, the memory controller 45 controls the selector 44 so that the 60I input video signal 52 and the output read from the field memory 43 are selectively outputted.
In the case of imparting the film image effects based on the 2:3:3:2 pull-down cycle in the pseudo manner, the linkage memorized by the selector 44 is as follows. The selector 44 selects the 60I input video signal 62 inputted to the input terminal 41 for the 60I video signal when the count values are (1), (3), (6) and (9), while selecting the output read from the field memory 43 when the count values are (2), (4), (5), (7), (8) and (10).
Therefore, at such timings that the write operation is being executed to the field memory 43 (at such timings that the count value of the cyclic counter 45a shows (1), (3), (6) and (9)), the selector 44 selects the 60I input video signal 62 from the input terminal 41 and outputs it. At such timings that the read operation is being executed to the field memory 43 (at such timings that the count value of the cyclic counter 45a shows (2), (4), (5), (7), (8) and (10)), the selector 44 selects the output from the field memory 43 and outputs it. Thereby, the selector 44 repeatedly outputs the 60I video signal already written in the field memory 43 until the write of the next video signal is executed as shown in the video signal 65 outputted from the selector in
The variation controller 47 sets the gain control value with respect to the gain controller 46 based on the frame synchronous signal of the 60I input video signal 52 inputted to the input terminal 42. At the time, the variation controller 47 changes the gain control value per field, and sets the gain control value so that the gain control value is changed when the video signal outputted from the selector 44 is different to the video signal of the field immediately before. Below is given a more detailed description.
In the case of imparting the film image effects based on the 2:3:3:2 pull-down cycle in the pseudo manner, the variation controller 47 sets video blocks A5 each comprising five fields.
As shown in the control value (gain) 66 in
The variation controller 47 recognizes the respective video blocks A5 based on the count values counted up by the counter 415a and determines the field positions in the respective video blocks A5. Further, the variation controller 47 judges if the relevant field is included in the minimum video unit group A51 or in the minimum video unit group A52 based on the determined field positions, and sets the gain control value based on a result of the determination.
The variation controller 47 sets the gain control value by repeating the foregoing control routine. Below is given a more detailed description.
A correspondence relation between the count value of the cyclic counter 45a and the gain adjustment amount of the gain controller 46 is previously set based on the setting of the minimum video unit groups A11 and A12. The variation controller 47 memorizes the correspondence relation between the set gain adjustment amount and count value (minimum video unit groups A51 and A52). In the case of adjusting the luminance in accordance with the 2:3:3:2 pull-down method, the correspondence relation memorized by the variation controller 47 is as follows. In the case of the minimum video unit groups A51 showing count values (1), (2), (6), (7) and (8), the variation controller 47 sets the gain adjustment amount of 1.0 times. In the case of the minimum video unit groups A52 showing count values (3), (4), (5), (9) and (10), the variation controller 47 sets the gain adjustment amount of 0.9 times. The control routine is repeated so that the gain adjustment amounts are set.
The gain controller 46 actually controls the gain in accordance with the gain control value set by the variation controller 47. More specifically, the gain controller 46 multiplies the luminance signal of the 60I input video signal 22 outputted from the selector 44 by the set gain control value to thereby change the gain of the video signal. Thus, the gain of the luminance signal is controlled for every two fields, three fields, three fields and two fields corresponding to the 2:3:3:2 pull-down cycle.
The renewal of the 60I video signal outputted for every two fields and three fields corresponding to the 2:3 pull-down cycle or for every two fields, three fields, three fields and two fields corresponding to the 2:3:3:2 pull-down cycle and the flicker effect obtained by controlling the gain of the luminance signal are thus combined, so that such visual effects as obtained in photographing using the 24P video signal in a film or the like can be easily obtained in the inputted 60I video signal without the input of the 24P video signal. The timing by which the memory controller 45 changes the output of the selector 44 and the timing by which the variation controller 47 changes the control value with respect to the gain controller 46 correspond to each other, and is controlled by the cyclic counter 45a. The cyclic counter 45a may be provided in either of the memory controller 45 and the variation controller 47 as far as the memory controller 45 and the variation controller 47 can be controlled based on the timing generated by the cyclic counter 45a provided in one of them. Further, the cyclic counter may be provided in both of them as far as the timings generated by the two cyclic counters correspond to each other.
In the present embodiment, the luminance (gain) may be adjusted based on the cycle of 1/30 second in the same manner as described in the embodiment 1.
According to the description of the embodiment 2, a device constitution comprising the gain controller 46 and the variation controller 47 (hereinafter, referred to as first constitution B1) is provided on a rear-stage side in a signal-transmission direction relative to a device constitution comprising the field memory 43, the selector 44 and the memory controller 45 (hereinafter, referred to as second constitution B2). However, as shown in
In the described embodiments 1 and 2, the present invention was applied to the device constitution in which the film image effects were generated in the 60I video signal in the pseudo manner. In an embodiment 3 of the present invention, the present invention is applied to a device constitution in which film image effects are generated in the 50I video signal (PAL video signal) in the pseudo manner.
Referring to reference numerals shown in
A signal processing executed by the video signal processing device is basically the same as that of the video signal processing device according to the embodiment 1. First, the digitalized 50I input video signal 220 is inputted from the input terminal 110 to the gain controller 140, and the frame synchronous signal 210 of the 50I input video signal 220 is inputted from the input terminal 120 to the variation controller 130. The 50I input video signal 220 inputted to the input terminal 110 and the frame synchronous signal 210 inputted to the input terminal 120 synchronize with each other as shown in
The variation controller 130 sets a gain control value of the gain controller 140 based on the frame synchronous signal of the 50I video signal. More specifically, the variation controller 130 handles four fields, which are continuous in the inputted 60I input video signal 220, as one video block A6, and sets the gain control value so that the gain control value changes per field in each video block A6.
As shown in the control value (gain) 230 in
Because the gain control value is differently set in the minimum video unit groups A61 and A62, the variation controller 13 is constituted as follows. The cyclic counter 130 comprises a cyclic counter 130a for repeatedly counting the four fields of 1-4. The cyclic counter 130a repeatedly provides count values of (1)-(4) for the respective fields constituting the 50I input vide signal 22. The variation controller 130 recognizes the respective video blocks A6 based on the count values counted up by the counter 130a and determines the field positions in the respective video blocks A6. Further, the variation controller 130 judges if the relevant field is included in the minimum video unit group A61 or in the minimum video unit group A62 based on the determined field positions, and sets the gain control value based on a result of the determination.
The variation controller 13 sets the gain control value by repeating the foregoing control routine. Below is given a more detailed description.
A correspondence relation between the count value of the cyclic counter 130a and the gain adjustment amount of the gain controller 14 is previously set, and the variation controller 130 memorizes the correspondence relation between the set gain adjustment amount and count value. The correspondence relation memorized by the variation controller 130 is as follows. In the case of the minimum video unit groups A61 showing count values (1) and (2), the variation controller 130 sets the gain adjustment amount of 1.0 times. In the case of the minimum video unit groups A62 showing count values (3) and (4), the variation controller 130 sets the gain adjustment amount of 0.9 times. The control routine is repeated so that the gain adjustment amounts are set.
The gain controller 140 actually controls the gain in accordance with the gain control value set by the variation controller 130. More specifically, the gain controller 140 multiplies the luminance signal of the 50I input video signal 220 inputted from the input terminal 110 for the 50I video signal by the set gain control value to thereby change the gain of the video signal. Thus, the gain of the luminance signal is controlled for every two fields and two fields (see
Thereby, even when the input video signal is 50I video signal, the output video signal thereof (50I video signal) can be vested with the film image effects in the pseudo manner.
In the foregoing case, the cycle in which the luminance (gain) is changed (cycle in which the flickers are generated) is 1/25 second, which is slightly shorter than 1/24 second as the originally desired cycle in which the luminance (gain) is changed, though the projected image having the frame rate of 25 frames per second can be displayed in the state where the flickers are generated. However, because a difference between the cycles is relatively small, the control operation according to the present embodiment can achieve the visual effects corresponding to those obtained from the 24P video signal. Further, in the present embodiment, the luminance (gain) variation point completely corresponds to the frame variation point, which can avoid any visual problem.
In the described embodiments 1-3, the flickers are generated in such a manner that the gain is changed to be 1.0 times and 0.9 times. However, the gain control value is not necessarily changed based on the magnifications. When the difference between the two gain control values is approximately 5-15% or more desirably approximately 10%, the visual effects in the projected image obtained when the 24P video signal is displayed can be most efficiently achieved in the pseudo manner. Other examples of the gain control value capable of obtaining the same effect are 1.05 times, 0.9t times, 1.1 times, 1.0 times and the like.
In the described embodiments, the present invention was applied to the device for executing the signal processing to the 60I video signal and the 50I video signal. These video signals are the interlace video signals in which a minimum video unit is a field and frame periods are 1/30 second and 1/25 second. However, it is needless to say that the present invention can be applied to a progressive video signal whose minimum video unit is a frame (for example 30P video signal).
In the case of applying the present invention to the interlace video signal, the variation controller preferably synchronizes a bundle of video blocks each equivalent to a second to the frame period of the video signal. Below is described a reason for doing so referring to
The 60I video signal and the 50I video signal to be controlled in the foregoing embodiments are the interlace signals. In the interlace signals, each frame as a component of the video signal is comprised of a pair of fields. In contrast to that, according to the present invention, the luminance is controlled per field as described.
In the case of applying the present invention to the interlace signal, the state where the variation point of the luminance signal synchronizes with the frames and located on the border of the frames and the state where the variation point of the luminance signal does not synchronize with the frame and located within the frame are generated. To be more specific about the location of the variation point of the luminance signal within the frame, the variation point of the luminance is located between the fields constituting the same frame. The location of the variation point within the frame leads to a luminance difference between the fields constituting the same frame, and a projected image thereby obtained gives the viewer the visual problem. Therefore, it is preferable that the location of the variation point of the luminance within the frame be avoided as often as possible.
However, in the case of applying the present invention to the interlace signal so that the film image effects can be generated in the pseudo manner, in particular, it is not possible to avoid the state where the variation point of the luminance is located within the frame. The possibility of such a location of the variation point of the luminance that causes the visual problem can be minimized in the following manner.
In the case of imparting the film image effects can be generated in the pseudo manner according to the present invention, it can be assumed that the bundle of video blocks each equivalent to a second, which was mentioned earlier, are continuously arranged in the video signal. In the case of generating the film image effects based on the 2:3:3:2 pull-down cycle in the pseudo manner, six of the video blocks A2 (10 fields) constitute the bundle of video signals each equivalent to a second, the bundle of video blocks A2 are continuously placed in the 60I video signal.
As shown in
As is clear from the foregoing description, in the case of applying the present invention to the 60I video signal so that the film image effects are generated based on the 2:3:3:2 pull-down cycle in the pseudo manner, the state where the variation point of the luminance is located within the frame can be less frequently generated when the bundle of video blocks each equivalent to a second synchronize with the frame period.
The control operation shown in
A video signal processing device according to the present invention exerts such an effect that a projected image, such as an image taken in a film, can be displayed and recorded in conventional receivers employing the NTSC system and the PAL system and VCR in a simplified circuit configuration and control method without inputting a 24P video signal, and is effective as a video signal processing device for executing an image conversion to a digitalized video signal.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2003-342992 | Oct 2003 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP04/13975 | 9/16/2004 | WO | 3/31/2006 |
