Method and system for deterring electronic video piracy through image rearrangement

Abstract

A method for frustrating unauthorized duplication of at least a portion of a sequence of images being embodied in digital data in a given order in a bitstream, the method including: storing data corresponding to an individual one of the plurality of images in at least one memory device in the given order; and, reading the data out from the at least one memory device in a pseudorandom order as part of the bitstream to provide a rearranged order of digital data different from the given order and adapted to frustrate conventional display of the sequence of images. A method for providing a bitstream having digital data that has been rearranged from a given order corresponding to a plurality of images so as to frustrate unauthorized reproduction of the images to a display device for receiving the digital data in the given order, the method including: storing at least a portion of the rearranged bitstream in a memory according to a pseudorandom sequence corresponding to the rearrangement; and, sequentially reading the data out from the memory in a the given order.

Description

FIELD OF THE INVENTION

[0002] The present invention relates to electronic video reproduction systems and more particularly to methods and devices for preventing unauthorized duplication of electronic video presentations.

BACKGROUND OF INVENTION

[0003] The present invention is described as it relates to digital movies and their presentation in theatres, however it should be understood to be equally applicable to other digital video presentations methods and systems.

[0004] A major problem with digital movies today is piracy, or the unauthorized reproduction thereof. Pirated copies of movies can be found on film and other electronic media, such as video tape, or magnetic or optical disk. Pirated movies are sold around the world and shown without any royalties being paid to the proper persons, e.g. the originators or studio. Accordingly, it is desirable that electronic video presentation systems be as secure as possible and as immune to piracy as possible.

[0005] In an electronic video presentation system dedicated to showing digital movies or video presentations, data representative of the movie or video presentation is relatively secure for most parts of the system. FIG. 1 illustrates such a system 10. In referring to the figures, like references designate like elements of the invention.

[0006] Referring to FIG. 1, a video presentation such as a movie is typically prepared at a location 20 such as a studio. The movie is typically displayed at a distinct location 30 such as a theatre. Using conventional processing elements 40 at the studio 20, a movie is captured and digitized, and compressed into a bitstream which is then encrypted to provide a secured, digital bitstream 50. The movie is reproducible from the bitstream 50. The encrypted bitstream 50 is transported to a remote location 30 by some means, such as a computer network or physical medium like a magnetic tape or disk, for example. In a theatre 30, the encrypted bitstream 50 is decrypted and decompressed using conventional processing elements 60. The decrypted, decompressed bitstream 70 is fed to projector 80 which displays it on a movie screen for example.

[0007] The physical studio 20 can be secured so as to protect the movie from being pirated. Between the studio 20 and theatre 30, the bitstream 50 is encrypted. Hence, even if the bitstream 50 is intercepted or stolen, sufficiently robust encryption techniques exist and are used to prevent easy reproduction of pirated copies of the movie. Within the theatre 30, decryption and decompression, using elements 60, happen almost simultaneously. This typically is provided on the same computer platform which can also be made sufficiently secure using conventional locked housings, or enclosures.

[0008] However, over the transmission link between decryption and decompression by elements 60 and projector 80, decrypted and decompressed signal 70 is conventionally a “clear” signal that can potentially be intercepted and stolen using appropriate equipment.

[0009] It is an object of the present invention to prevent theft or unauthorized duplication of signal 70 of a video presentation such as a movie.

SUMMARY OF INVENTION

[0010] A method for frustrating unauthorized duplication of at least a portion of a sequence of images being embodied in digital data in a given order in a bitstream, the method including: storing data corresponding to an individual one of the plurality of images in at least one memory device in the given order; and, reading the data out from the at least one memory device in a pseudorandom order as part of the bitstream to provide a rearranged order of digital data different from the given order and adapted to frustrate conventional display of the sequence of images.

[0011] A method for providing a bitstream having digital data that has been rearranged from a given order corresponding to a plurality of images so as to frustrate unauthorized reproduction of the images to a display device for receiving the digital data in the given order, the method including: storing at least a portion of the rearranged bitstream in a memory according to a pseudorandom sequence corresponding to the rearrangement; and, sequentially reading the data out from the memory in a the given order.

BRIEF DESCRIPTION OF THE FIGURES

[0012] The advantages and aspects of the present invention will be more fully understood in conjunction with the following detailed description and accompanying drawings, wherein:

[0013] FIG. 1 illustrates a block diagram of a conventional movie production, delivery and presentation system discussed in the background of the invention;

[0014] FIG. 2 illustrates a more detailed view of a presentation portion of the system of FIG. 1;

[0015] FIG. 3 illustrates the presentation portion of FIG. 2, adapted according to a preferred form of the present invention; and,

[0016] FIG. 4 illustrates rearrangement of an image or frame of a movie according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0017] As will be discussed herein with reference to FIGS. 3 and 4, the present invention basically operates by rearranging at least some if not all of the individual images of the movie transmitted to the projector 80 such that even if stolen, these images cannot be readily reconstituted into a useful reproduction of the movie. As is understood by those possessing ordinary skill in the pertinent art, a digital video or movie includes a series of images or frames displayed sequentially. On film, each image is complete and intact. In a digital movie, each image is made up of pixels. Of course, pixel is short for Picture Element, and is the smallest single addressable element in a graphic image. Each pixel is well defined and arranged in rows and columns to form a two-dimensional array as is well understood. The array of pixels forms the image to be displayed as a frame of the movie. The present invention utilizes the fact each image in a digital movie is divided into pixels, and manipulates the individual images to further protect the movie from piracy.

[0018] Referring now to FIG. 2, therein is illustrated a block diagram of apparatus provided in a theatre 30 which includes image source 90 and projector 80. Image source 90 can take the form of decryptor and decompressor 60 as illustrated in FIG. 1, or any other suitable configuration for providing digital images to projector 80. Image source 90 provides digital signal 70 to projector 80. As was discussed, the signal 70 includes pixels which make up the individual images of the movie displayed by the projector 80, frame by frame. Depending on the projector 80, the pixels corresponding to any given image in the signal 70 may be displayed simultaneously or sequentially as in a raster scan. In either case, each image is transmitted in signal 70 as individual pixels or blocks of pixels in a fixed order which does not change from image to image, (e.g. frame to frame).

[0019] The present invention prevents piracy of signal 70 and hence the movie displayed using projector 80 by varying the order of the pixels or blocks of pixels of each image in the signal 70 in a random manner from image to image.

[0020] Referring now to FIG. 3, therein is illustrated a configuration 100 including the theatre 30 configuration of FIG. 2 adapted according to the present invention to prevent unauthorized duplication of the signal 70′. The configuration 100 includes frame buffer 110 and randomizer 120. An input of the frame buffer 110 is coupled to an output of the image source 90. The output of the frame buffer 110 is coupled to an input of randomizer 120. Signal 70′ is transmitted between an output of randomizer 120 and an input of derandomizer 130 as is illustrated in FIG. 3. An output of the derandomizer 130 is coupled to an input of frame buffer 140 and an output of the frame buffer 140 is coupled to an input of projector 80.

[0021] In a preferred embodiment of the present invention, frame buffer 110 and randomizer 120 are in close physical proximity to image source 90, and preferably located in the same housing or enclosure 95 as the image source 90.

[0022] According to the present invention, image source 90 provides an output to frame buffer 110. Frame buffer 110 holds at least part of each image output from image source 90. As is understood by those possessing ordinary skill in the pertinent art, frame buffers 110 and 140 each include an array of addressable memory locations which each has a unique identifier or memory address assigned to it. Frame buffers and storage devices and memories are of course well known and widely employed in the video related arts. Randomizer 120 accesses contents of the memory addresses of frame buffer 110 in a pseudo-random manner and writes the contents of these pseudo-randomly accessed addresses sequentially as part of signal 70′.

[0023] As is well understood, a pseudo-random number generator can be used to generate a pseudo-random sequence that satisfies statistical tests for randomness. The random sequence provided by these types of generators can be repeated by starting from the same starting point. By using a pseudo-random sequence to control the order of access and readout of data as stored by the frame buffer 110, a pseudo-randomized version of each image or frame that make up the movie to be displayed by projector 80 is transmitted as signal 70′ on the vulnerable link between image source 90 and projector 80. Hence the signal 70′ is randomized and less likely, if intercepted, to be effectively used than is signal 70 of FIG. 2. Each image or frame of the movie which was randomized using frame buffer 110, randomizer 120 and pseudo-random sequence generator 125 is reconstructed using derandomizer 130, pseudo-random sequence generator 135 and frame buffer 140.

[0024] The derandomizer 130 uses pseudo-random sequence generator 135 to generate the same pseudo-random sequence as was utilized by the randomizer 120 and pseudo-random sequence generator 125, to apply the randomized data in signal 70′, corresponding to an image, to the appropriate memory addresses of frame buffer 140. In other words, data is read-out from memory addresses of frame buffer 110 selected according to a pseudo-random sequence and applied to memory addresses of frame buffer 140 selected according to the same pseudo-random sequence. After being applied and stored in the frame buffer 140, the data is then supplied in a conventional manner to the projector 80 which displays the corresponding image. Thus, for any given image of a movie, data corresponding to that image is stored in identical corresponding addresses in the frame buffers 110 and 140 as that data is conventionally supplied to frame buffer 110, pseudo-randomly read out from frame buffer 110, applied to frame buffer 140 utilizing the same pseudo-random sequence as was used to read frame buffer 110, and conventionally read-out from frame buffer 140.

[0025] It should be understood, that unlike image source 90 which may take the form of conventional decryptor/decompressor 60 and require significant processing capabilities and a physically large computing platform, derandomizer 130 and frame buffer 140 can be made relatively physically smaller, and hence suitable for placement within a typical projector 80 enclosure 85 without significant modifications being made thereto. In a preferred form of the present invention, the derandomizer 130 and frame buffer 140 are physically positioned within the projector 80 housing, or enclosure 85.

[0026] Referring now to FIG. 4, there is illustrated an example of how an individual image or frame 150 of a movie can be rearranged according to the present invention for transmission as part of signal 70′. Using the pseudo-random sequence, images 150 or frames of the movie to be displayed using projector 80 can advantageously be rearranged according to the present invention differently in a random manner. It should also be understood while the discussion of the present invention hereto has been as it relates to individual pixels, the block size or size of a pixel group, utilized for randomization, can vary from a substantial portion of each image down to individual pixels depending upon particular design criteria.

[0027] For example, in digital videos the use of macroblocks, four blocks of luminance, one Cr block and one Cb block is well known. In a preferred form of the present invention, individual macroblocks are rearranged using the methodology set forth hereto.

[0028] Referring still to FIG. 4 therein is illustrated an original image 150 supplied by image source 90. Image 150 includes groups of pixels 1-9. Analogously, reconstructed image 150″ provided by frame buffer 140 to projector 80 also includes groups of pixels 1-9 in the same order and respective positions as in image 150. It should be understood images 150 and 150″ are respectively protected within image source enclosure 95 and projector enclosure 85. Accordingly, the more robust enclosures 85 and 95 are, the more secure images 150 and 150″ are. Image 150′ is a representation of image 150 which has been rearranged according to the present invention for transmission as part of signal 70′. As set forth, a pseudo-random sequence utilized by randomizer 120 and derandomizer 130 is necessary for proper de-arranging to generate image 150″. As can be seen in FIG. 4, the relative arrangement of pixel groups 1-9 in image 150′ is changed dependent upon the utilized pseudo-random sequence as compared to the relative arrangement of pixel groups 1-9 in image 150. For example, pixel group 9 in image 150′ has taken the relative position of pixel group 1 in image 150. Likewise, pixel group 1 in image 150′ has take the relative position of pixel group 6 in image 150 for example. It should be understood this particular pixel group rearrangement is for purposes of illustration only, as in a preferred embodiment the relative arrangement of pixel groups can change from image to image, or frame to frame.

[0029] Although the invention has been described and pictured in a preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form, has been made only by way of example, and that numerous changes in the details of construction and combination and arrangement of parts may be made without departing from the spirit and scope of the invention as hereinafter claimed. It is intended that the patent shall cover by suitable expression in the appended claims, whatever features of patentable novelty exist in the invention disclosed.

Claims

1. A method for frustrating unauthorized duplication of at least a portion of a sequence of images being embodied in digital data in a given order in a bitstream, said method comprising: storing a portion of said data corresponding to an individual one of said plurality of images in at least one memory device in said given order; and, reading said stored data out from said at least one memory device in a pseudorandom order as part of a bitstream to provide a rearranged order of digital data different from said given order and adapted to frustrate conventional display of said sequence of images.

2. A method for providing a bitstream having digital data that has been rearranged from a given order corresponding to a plurality of images so as to frustrate unauthorized reproduction of said images to a display device for receiving said digital data in said given order, said method comprising: storing at least a portion of said rearranged bitstream in a memory according to a pseudorandom sequence corresponding to said rearrangement; and, sequentially reading said data out from said memory in said given order.