Methods of transmitting and receiving image streams, data medium, transmitting device, conversion module for said methods

FIELD: physics, computer engineering.

SUBSTANCE: invention relates to computer engineering. The method of transmitting a stream of unencrypted images involves encoding the stream of images and sending a compressed stream of images to at least one receiving device. Before encoding, images of the unencrypted stream of images are converted via a secure reversible conversion to obtain a converted stream of images which is encoded and transmitted in place of the unencrypted stream of images. The secure reversible conversion converts each image from a sequence of unencrypted images.

EFFECT: high security of a stream of unencrypted images.

12 cl, 9 dwg

 

The invention relates to a method of transmitting and receiving streams of images. The invention also relates to the media, the transmitting device and the module reverse conversion or transformation module designed to implement these methods.

In prior art methods of transmission of the stream of images in an unencrypted form contain the stages on which:

encode the stream of images to produce a compressed stream of images, and

pass the compressed stream of images, at least one receiving device.

In prior art methods of receiving streams of images sent according to the aforementioned method, contain the following:

take a stream of images, and

decode the received stream of images to obtain a decompressed stream of images.

Open or unencrypted stream of images is a flow of images that when displayed on the screen can be directly visible and understandable to the person. For example, this sequence of multimedia programs such as film or audiovisual program. Unencrypted stream of images is unprotected. Therefore, it can be viewed using any receiver equipped with a display device and a suitable decoder. In particular, nez is an encrypted stream of images is not encrypted so to view it was possible under certain conditions.

Usually, in order to protect the unencrypted stream of images, the methods of the prior art also includes the encryption of the compressed stream of images so that the viewer unencrypted stream of images is possible, under certain conditions, as, for example, by purchasing access rights to it.

Accordingly, in prior art methods of admission typically include decryption of the stream of images before it is decoded. Thus, the stream of images is protected during transmission from the transmitting device to the receiving device.

Encryption is usually performed after encoding. Indeed, the execution of these two operations in reverse order when the existing encryption methods leads to a significant reduction in the degree of compression achieved by the encoder.

The compression ratio is the ratio of the amount of information to compress the amount of compressed data obtained after compression.

In the known methods for transmitting and receiving a stream of images obtained at the output of descrambler, who stream of images, is no longer secure. Thus, illegal use is to obtain decrypted or decompressed stream of images to done is to its retransmission users, who did not pay for the appropriate access rights.

To overcome this problem it has been proposed to combine the decoder and descrambler in a single electronic component, known as SOC (chip) in order to complicate the receiving stream of images. However, for transactions decryption and decoding of such a component in the General case uses a clear external RAM (random-access memory). Therefore, there is still the possibility of obtaining a decoded stream of images from the RAM.

If the receiving device is a personal computer (PC), it is also possible to obtain the decrypted stream of images by intercepting calls to the driver for your graphics card on this computer.

To overcome this vulnerability previously also already been proposed to encrypt the decompressed stream of images at the output of the decoder. Encrypted thus the stream of images is decrypted just before it will be displayed on the screen. Thus, this method protects the connection between the host device and the display device. This can be used, for example, the HDCP (digital content protection copy in broadband networks). However, in this method, the decoded stream from which images can be obtained before submitting it to the input of the decoder or the output, but before it is encrypted. In this case, the encryption is performed at the output of the decoder is inefficient with respect to this kind of illegal access to the stream of images.

Another complication occurs when the encoder, scrambler, descrambler and decoders are propietary equipment. Indeed, in the case of gaps in the security system only the owner of the equipment may take measures to eliminate gaps. Third parties may not offer a solution to correcting the functioning of this equipment.

The invention is directed to find a way to eliminate at least one of these vulnerabilities. The objective of the invention is a method flow open or unencrypted images, in which the phase encoding method includes converting images unencrypted stream of images through secret reversible transform to obtain a transformed or converted stream of images, which is encoded and sent instead of the unencrypted stream of images, it's a secret reversible transformation that converts each image of the sequence unencrypted images, is as follows:

in the same permutation of the positions of pixels for each image from posledovatel the particular unencrypted images and/or

in the same changing colors of pixels for each image sequence unencrypted images so that the change applied to each unencrypted image directly perceived by a person, when displaying the converted image on the screen without first applying the inverse transform.

The term "reversible" transformation refers to the fact that there is an inverse transformation used to obtain the unencrypted stream of images from an encrypted stream of images. This inverse mapping is the inverse of the reversible transformation.

The term "secret" refers to the fact that the conversion should not be disclosed and to be known.

The aforementioned method is used to avoid actions upon receipt of the compressed stream of images at the output of descrambler or decompressed stream of images at the output of the decoder. Indeed, the stream of images, which you can get on these two outputs is converted to a stream of images. Now this converted stream of images visually different from the unencrypted stream of images. Thus, his view without prior application of the inverse transform will be neudovletvoritel the typical user. Characteristics of the transformation, and hence the inverse transformation, are secret. The transmitted stream of images, thus protected even at the decoder output.

Moreover, in order to realize this method is not necessary to perform any action in relation to the existing encoder, scrambler, decoders and descramblers.

Moreover, the fact that to convert unencrypted images are only rearranging the positions of the pixels and/or to change the colors of pixels limits the decrease of the degree of compression achieved by the encoder.

Embodiments of the method of transmission may contain one or more of the following characteristics:

- secret reversible transformation such that the compression ratio of the converted stream of images identical to 55% compression ratio obtained when the images are not converted;

- secret reversible transformation is an elementary transformation, or a combination of elementary transformations, selected from the group including:

building image, unencrypted symmetric image with respect to an axis parallel to the edge of the image;

the permutation of blocks of pixels unencrypted image, and

adding offset values to the color of at least the underwater pixel block non-encrypted image;

- convert is able to convert an unencrypted stream of images in the converted stream of images containing the same number of pieces of information of each image as an unencrypted stream of images;

the method includes changing the secret reversible conversion at specified intervals or on command;

the method includes sending a message containing the cryptogram which enables a receiving device to find the inverse transform, which can be used to build an unencrypted stream of images from the converted stream of images;

the method includes turning on the message in the converted stream of images before the encoding of the stream so that the message is sent along with the stream of images;

the method includes encrypting the compressed stream of images before sending it.

These embodiments of the method of transmission additionally have the following advantages:

allows the choice of this transformation, which leads to a small decrease in the performance of the encoder and, therefore, it is possible to save bandwidth required to transmit the converted stream of images, at a level close to that trebuetsya of the unencoded stream of images;

building a symmetrical images of the source, or the permutation of blocks of pixels retain the bandwidth required to send a stream of converted images at the level close to the bandwidth required to send an unencrypted stream of images;

using the conversion, it does not reduce the amount of information contained in each clear image that allows you to build from the converted images unencrypted images that contain exactly the same amount of information as sent unencrypted image;

regular changing secret conversion makes it possible as deterioration unsatisfactory for user quality of displaying the converted stream of images and increase security by restricting the time available for illegal determine the inverse transform;

transmission of the cryptogram in the message sent in the converted stream of images, eliminates the need for additional communication channel.

The object of the invention is also a method for displaying a stream of images that are sent using the aforementioned method, in which after decoding a stream of images the way VC is uchet the transformation of images converted or converted stream of images by inversion secret conversion, used in the administration, in order to obtain the unencrypted stream of images and then display the resulting stream of images.

The object of the invention is a storage medium containing instructions for implementing any of the above methods, when these instructions are executed by an electronic computer.

The object of the invention is also a device for transmission of the stream of images in an unencrypted form, the device includes:

encoder stream of images made with the possibility of obtaining a compressed stream of images, and

the transmitter compressed stream of images, at least one receiving device,

the conversion module, configured to convert the image unencrypted stream of images through secret reversible transformation to obtain the converted stream of images encoded and transmitted instead of the unencrypted stream of images, it's a secret reversible transformation that converts each image of the sequence unencrypted images, is as follows:

in the same permutation of the positions of pixels for each image of the sequence unencrypted images; and/or

in the same change colors peak in the fir for each number in the sequence unencrypted images so the transformation applied to each unencrypted image directly visible to a person if the transformed image is displayed on the screen without first applying the inverse transform.

Finally, the object of the invention is also the inverse transform module, configured to implement the above-mentioned method of receiving, providing, using inversion secret conversion applied when sending, converting the converted image stream of images to produce an unencrypted stream of images.

Brief description of drawings

The invention will become clearer from the following description given as a non-restrictive example, with reference to the accompanying drawings, on which:

figure 1 - schematic view of the transmission system and the reception of the stream of images,

figure 2 - schematic view of unencrypted image

3 and 4 are schematic views of the transformed image obtained from an unencrypted image in figure 2,

5 is a schematic view of the structure of the message transmitted from the image stream,

6 is a block diagram of the operational sequence of the method of transmission and reception of the stream of images through the system shown in figure 1,

7, 8 and 9 - sh the pragmatic views of alternative embodiments of the system, shown in figure 1.

In the drawings, the same reference position is used to denote the same elements.

Here and below in this description of the characteristics and functions well known to experts in the art are not described in detail. Moreover, the terminology used corresponds to the terminology used in relation to conditional access to multimedia content. For more information about the terminology the reader is referred to the following document:

"Functional model of a conditional access system", the review of the European broadcasting Union (EBU), Technical European broadcasting Union, Brussels, Belgium, No. 266, December 21, 1995

Figure 1 shows a system 2 for transmitting and receiving the stream of images.

The stream of images corresponds to, for example, the sequence of multimedia programs such as a television, film or audiovisual program.

The unencrypted stream of images generated by the source 4 and is transmitted to the device 6 for sending this stream of images to the set of receiving devices via the network 8 transfer information.

The network 8 is typically a network information transfer long range, such as the Internet or satellite network, or, again, a wireless network such as the on of those used for digital terrestrial television (DTTV unit).

For simplicity, figure 1 shows only two of the host devices 10 and 12.

The device 6 includes an encoder 16 that is able to compress a stream of images, which is fed to one input 18, and is also able to return a compressed stream of images at the output 19. The encoder 16 is a digital encoder with a function of processing digital streams of images. For example, the encoder operates in accordance with the standard MPEG2 (expert group on moving images, the Moving Picture Expert Group - 2) or with the standard ITU-T N.

The compressed stream of images is sent to the input 20 of the scrambler 22. Scrambler 22 encrypts the compressed stream of images in order to view it was possible, under certain conditions, such as the purchase by the user of the receiving device access rights. The stream of encoded images is returned to the output 24 connected to the input of the multiplexer 26.

Scrambler 22 encrypts the compressed stream of images by means of the control word CW, which is supplied by the generator 32 key on it, and the system 28 conditional access, better known as CAS. Typically, the encryption is performed according to the standard such as DVB-CSA (Common scrambling algorithm digital television), ISMA Cryp (encrypted streaming media Internet Alliance), IPsec (key Protocol information safety is snasti when using the IP Protocol of the Working group on resource records), SRTP (secure Protocol for data transfer in real time), etc. System 28 generates the ECM (control messages on the right), containing the cryptogram CW* control word CW generated by the generator 32 and used by the scrambler 22. These messages and the flow of encrypted images are combined by the multiplexer 26 to which they are respectively served by the system 28 and conditional access scrambler 22 and then transmitted over the network 8.

The device 6 has an additional module 30, is arranged to convert an unencrypted images. Module 30 converts the stream unencrypted images received from the source 4, the flow of the converted images. It is connected between the output of the source 4 and the input 18 of the encoder 16. Thus, the image encoded by the encoder 16 is the image converted by the module 30, and not unencrypted image. This module 30 is aimed at the protection of the stream of images after the decryption and decoding in the receiving devices 10 and 12. In this regard, the image conversion must be directly visible to the user, which did not apply the inverse transform before displaying on the screen. Preferably, the converted image as much as possible different from unencrypted images from which they were obtained is. To do this, for each image of the received stream unencrypted image module 30 applies the secret reversible conversion So

Preferably, this transformation T was chosen so that the compression ratio achieved by the encoder 16, did not change significantly. The compression ratio achieved by the encoder relies modified within 55%, preferably 15% from compression, resulting from the encoding of the stream unencrypted images. To achieve this goal, the transformation T is selected as a function of the characteristics of the encoder.

Moreover, the transformation T is chosen so as not to reduce the image quality. In this regard, the converted images contain the same amount of information as clear text image.

The transformation T in this document is obtained by combination of several reversible elementary transformations Tei. More specifically, we use only two families of elementary transformations Tei:

elementary transformations, which rearrange the positions of the pixels unencrypted image, and

elementary transformations, which change the color of the pixels of the image.

Elementary transformations have a common characteristic, namely, that do not change the correlation between successive images asasif is consistent stream of images. Consequently, there is no substantial change in the degree of compression. Indeed, in the encoding MPEG2 or N this limits the generation of encoder key frames.

As an example, the definition of six elementary transformations Te1, ..., Te6. Elementary transformations Te1, ..., Te3move between the pixels unencrypted image, The4performs a cyclic permutation of the three blocks of pixels unencrypted image, and The5and Those6change color of image pixels. In this non-limiting example, convert The5and Those6described in the context of the YUV color model. However, without departing from the technical field to which the invention relates, elementary transformations that change the color, of course, can be equivalent described in the context of any other color models, for example, RGB (Red Green Blue red, green, blue), well known to specialists in this field of technology.

As an example, the transformation Te1swaps the left and right pixels. Figure 2 shows the open or unencrypted image 34 to the application to him of this elementary transformation. The corresponding transformed image 36 shown in figure 3. The image 36 is symmetrical image 34 relative about whom and 38, parallel to the vertical edge of the image 34.

Convert The2swaps the top and bottom of the open image. The converted image 40 obtained as a result of this elementary transformation to the image 34 shown in figure 4. The image 40 is symmetrical image 34 about the axis 42 parallel to the horizontal edge of the image 34.

Convert The3moves the seat, at least one block of pixels of the open image with another block of pixels of the same open image. Preferably, blocks, swap converting The3were the same as the units used in the encoding. For example, blocks of 16 by 16 pixels coincide with the blocks used in MPEG2 and N. Thus, the permutation of blocks of pixels limits the decrease of the degree of compression achieved by the encoder 16.

Elementary transformation of Those4performs a cyclic permutation of at least three blocks of pixels of the open image. As in the case of elementary transformations Te3, swap the blocks are the same as the units used in the encoding algorithm.

Preferably, for Those transformations3and Those4identity swap blocks was parameterized value.

Change the s Te 3adds a digital offset to the values of the component chrominance U and V images known as chroma values. The value of this offset can be parameterized. In the encoding operations in accordance with the standards N and MPEG2 main part of the information used to compress the stream of images is brightness, which is denoted by Y. on the Contrary, the chrominance components U and V are not taken into account by the encoding algorithm. Therefore, it becomes possible to change the component values U and V, without touching the encoder 16 and, thus, without changing the compression ratio.

Elementary transformation of Those6from my side, inverts the values of the chrominance U and V for each pixel of the open image.

These elementary transformations stored in the memory 50 connected to the device 6.

The transformation T is obtained by combining one or more of the above-mentioned elementary transformations Tei. The combining is carried out by successive application of several elementary transformations (Those to the same open image in a predetermined order. The transformation T, therefore, is a combination of several reversible elementary transformations Tei.

To construct the inverse transformation T-1 you must know the combination used by elementary transformations, and, in the case when these elementary transformations are used in a parameterized form, you need to know the used parameter values. This information is kept secret in order to prevent the possibility of constructing the inverse transformation T-1an unauthorized user.

Here the module 30 also generates a message containing the cryptogram with secret information, allowing you to build the inverse transform T-1. The term "cryptogram" refers to the fact that the message itself does not contain information that allows you to build a transformation T-1. The information contained in this message, must be combined with the information that must be received in the receiving device, while it is pre-recorded or there or should be there measured or calculated.

Thus, the cryptogram may be an identifier for a particular combination of reversible elementary transformations Tei. The receiving device should then have a means such as, for example, a lookup table, for each identifier, which must be obtained to link the inverse transform T-1that you want to use to make education is a great conversion of the stream of images.

The cryptogram may also contain the ID of the parameters. In this case, the receiving device must contain means such as, for example, the lookup table in order to associate this ID with your settings.

The cryptogram can also be obtained by encrypting the secret information, for example, executable code inverse transform T-1using symmetric or asymmetric encryption. Then, the receiver builds a transformation T-1by decrypting the received cryptogram using pre-recorded secret key. This way can be encrypted identifiers of the parameters of elementary transformations.

For example, figure 5 shows the message structure 54 generated by the module 30 and containing secret information, allowing you to build the inverse transform T-1. Message 54 includes field 56, which contains a cryptogram T* with secret information, allowing you to build the inverse transform T-1. The structure of this message is identical or similar to the message structure of the ESM. Therefore, it is not necessary to describe in detail.

Message 54 also includes field 58, containing access conditions (SA), designed to compare them with access rights previously the backgrounds in the receiving device to allow or otherwise prohibit construction of the inverse transformation T -1.

Message 54 contains:

box 60 containing information intended for message authentication 54, for example, the signature S, and

field 62 containing the information used to verify the integrity of messages 54, for example, CRC (cyclic control code for redundancy).

Finally, the module 30 can also insert a message 54 to the stream of converted images before zakodirovannie so that the message is transmitted together with the flow of the converted images. Message 54 is inserted into the stream of converted messages so that the compression ratio achieved by the encoder 16, did not change significantly. In this regard, there are a variety of ways. For example, the message 54 may be referred to as Teletext. As a result, the converted image is added at least one line on which the message 54 is encoded by the color code.

Message 54 can also be transmitted in the stream of converted images using the method of digital watermarking. However, this method is preferable to simplify in order to take into account the fact that for subsequent conversions is not necessary to guarantee the sustainability message is inserted in the image. Indeed, if the subsequent image conversion would fluctuate message 54, t is impossible to construct the inverse transform T -1: it would not have been a breach in the security system.

The module 30 is made, for example, in the form of a programmable electronic computer is able to execute instructions stored on the storage media. In this regard, the module 30 is connected to the memory 50, and a memory 50 contains the instructions necessary to implement the method shown in Fig.6.

In the receiving device 10 includes a receiver 70 transmitted stream of images. This receiver 70 is connected to the input of the demultiplexer 72, which first transmits a stream of images on descrambler 74, and then transmits control messages to access the ESM and message control access rights EMM processor 76 security. The processor 76 is typically a hardware component that contains sensitive information such as cryptographic keys or access rights, which can only be used by legitimate users. In order to maintain the confidentiality of this information, it is designed to be resistant against hacker attacks as possible. Therefore, it is more resistant to attacks than other components of the device 10. For example, the security processor may be a smart card with an electronic processor. The security processor may also be a software module running electric is authorized by the computer.

For example, the CPU 76 has a memory 78, containing various cryptographic keys and access rights for decrypting the encrypted image.

Descrambler 74 decrypts the encrypted stream of images using the open control word CW sent by the processor 76. The decrypted stream of images is transmitted to the decoder 80, which it decodes. Decompressed stream of decoded images or a stream of images is transmitted to the graphics card 82, which controls the display of the stream of images on the device 84 display, equipped with a screen 86. Here graphics card 82 contains the module 88 inverse transformation. This module 88 is arranged to construct the inverse transformation T-1and applying the inverse transform to obtain the open flow of images. In this regard, Board 82 has an electronic computer 90 connected to the memory 92, which contains instructions necessary to implement the method shown in Fig.6.

The device 84 display configured to display obtained from a received stream open or decoded stream of images on the screen 86.

For example, the device 12 is identical to the device 10 and will not be described in detail.

Now the operation of the system 2 will be described in more detail with what Alcoy on the way, shown in Fig.6. This method essentially consists of a phase 100, which is passed a stream of images, and phase 102, which sent a stream of images is taken.

In the early phase 100 to step 104 is building conversion So Here, at predefined intervals is the activation procedure of building a new convert So Predetermined intervals are, for example, at regular intervals of time lasting less than 20 seconds, and preferably less than 10 seconds.

Then, at step 106 is building a message 54, the corresponding transformation t the same time, at step 108 the thread open images converted by applying the transformation T.

Next, at step 110, the message 54 is inserted into a stream of images, and then the resulting stream is transmitted to the encoder 16.

At step 112, the encoder 16 encodes the converted stream of images to produce a compressed stream of images.

At step 114, the compressed stream of images encrypted by the scrambler 22 using the control word CW generated by the generator 32.

At step 116 MUX encrypted stream of images and corresponding ECM messages generated by the system 28. Finally, at step 118, this multiplexed information is transmitted to different pickup the major devices.

Phase 102 begins with step 120, which is used for reception, followed by demultiplexing the transmitted multiplexed information. Then, the stream of images is transmitted to descrambler 74, while messages ECM and EMM is transmitted to the processor 76.

At step 122, the processor 76 decrypts the cryptogram CW* control word and sends the code word CW to descrambler 74.

At step 124 descrambler 74 decrypts the encrypted stream of images using the obtained code word.

At step 126 the decrypted stream of images is sent to the decoder 80, which decodes it. Received decompressed stream of images is then passed to the module 88 inverse transformation.

At step 128 module 88 selects the message 54 from the received stream of images.

Then, at step 130 compares the conditions of access to CA pre-recorded rights of access (TdA). If the received access SA does not correspond to the access rights TdA, then at step 132 it is not possible to construct the inverse transform T-1. Otherwise, at step 134 using the cryptogram T* is the construction of the inverse transformation T-1.

At step 136 the converted stream of images applies the inverse transform T-1to obtain the open flow of the images, which stage 138 is displayed on the screen 86.

7 shows a system for transmission and reception of the stream of images. This system 150 is identical to system 2, with the following exception:

module 88 is made in the form of block 152, which is mechanically independent from the device 10 and device 84 display, and

graphics card 82 is replaced by a graphical map 154, which no module 88.

This unit 152 is located between the graphics card 154 and device 84 display.

This variant embodiment of the invention is used to obtain the transmission system of the stream of images that satisfy the cryptanalysis and does not require any modification of the receiving device 10. Indeed, it is enough to add the block 152 to provide additional protection to the transmitted stream of images.

On Fig illustrates a system 160 that is identical to system 2, with the following exception:

the device 84 of the display is replaced by device 162 of the display that contains the module 88, and

graphics card 82 is replaced by a graphical map 164, which no module 88.

For example, in this embodiment, the device 10 is a Central processor of the personal computer. Descrambler encoder 74 and 80 are implemented on a removable USB flash drive, universal serial bus (USB), the United center is inim processor. This implementation provides a flow of images inside a personal computer between the USB and the device 162 display.

Figure 9 shows the system 170 that is identical to system 2, except that the device 10 is replaced by the host device 172. The device 172 is identical to device 10 except that it additionally contains a module 174, configured to encrypt the decompressed stream of images obtained at the output of the decoder 80. The device 172 via the local network 178 is connected to various user terminals. To simplify the drawing shows only two terminals 180 and 182.

The terminal 180 includes a deciphering module 184, is able to decrypt the encrypted through zashifrovyvaya module 174, the flow of images. Then the module 184 transmits the decrypted stream of images on module 88, which builds open stream image before it is displayed.

For example, the terminal 182 is identical to the terminal 180.

In this embodiment of the invention the method is used to protect stream of images transferred between the decoder 80 and zashifrovyvaya module 174, and between the deciphering module 184 and module 88 inverse transformation.

There are many other options for the implementation of the Soberania. For example, open the image may come from a source 4, which itself contains the decoder line, satellite connection, or Internet connection.

Using a secret transformation and inverse transformation can be activated, and Vice versa deactivated at a network endpoint.

Module 88 may be made in the form of additional hardware or as a software module executed by the electronic computer.

Alternatively, the message 54 is transmitted separately from the converted stream of images. It can be transmitted through the connection type to point-to-point connection or a point-multipoint or through another connection that uses a single channel in the network 8 or other network. For example, it may be transmitted through a special service level of the transport stream of images.

Message 54 can also be multiplexed with the flow of images and messages ECM. In this case, on the side of the receiver it is passed to the module 88 inverse transformation simultaneously with the decompressed stream of images. Message 54 may also be the ECM message constructed by inserting the cryptogram T* in the ESM message known under the existing prior art method. Then, to this end, the module 30 provides 28 the cryptogram T*.

The generator 32, si is the subject 28, scrambler 22, the processor 76 and descrambler 74, which are used to protect the contents in accordance with the prior art, can be omitted or deactivated, all or partially, known to specialists in this field of technology method.

Alternatively, the transformation T can be constructed using elementary transformations, selected from the family of elementary transformations other than the above two families.

In other embodiments, the implementation of the new transformation T is encoded by a predetermined law and the particular characteristics of the open image such as color of the individual pixels of this image. In this way a new inverse transformation T-1built according to the law corresponding to this predetermined law, and the same characteristics of the same open image. For example, open the picture used for encoding a new transformation T, is converted using a new transform, and using the old conversion. On the side of the receiving device to open the image obtained by using the old reverse. Then a new transformation T-1built on an open image, obtained by applying the old inverse transformation. In affect, the, in this embodiment, it is no longer necessary to insert a special message such as the message 54, the stream of images received by a receiving device.

Alternatively, the construction of a new transformation T is activated when the command is received. For example, the command is automatically generated by the encoder 16 at each change of scene or each time you generate a new key frame.

Alternatively, the graphics card also has a model to encrypt a stream of images transmitted along the line connecting the receiving device 10 to the device 84 display. Accordingly, the device 84 display equipped with a module for decrypting the encrypted stream of images. For example, these modules are built to meet the standard high-bandwidth digital content protection (HDCP). The inverse transform is then carried out either before entering the stream of images on zashifrovyvaya module or the output of the deciphering module.

In this description, the term "scramble" and "descrambling" rely equivalent to the terms "encrypt" and "decrypt", respectively.

The contents of this description may also be applied to digital rights management (DRM).

1. The mode of transmission of unencrypted stream of images containing phases in which:
the code is display (112) stream of images to produce a compressed stream of images and
send (118) a compressed stream of images, at least one receiving device,
however before encoding transform image unencrypted stream of images through secret reversible transform to obtain a transformed stream of images encoded and transmitted instead of the unencrypted stream of images, and the secret reversible conversion converts each image of a sequence of unencrypted image:
by the same permutation of the positions of pixels for each image of the sequence unencrypted images and/or
by the same changes of colors of pixels for each image of the sequence unencrypted images so that the change applied to each unencrypted image directly perceived by a person when displaying the converted image on the screen without first applying the inverse transform.

2. The method according to claim 1, in which the secret reversible transformation provides the compression ratio of the converted stream of images within 55% of the degree of compression obtained without converting the stream of images.

3. The method according to claim 1, in which the secret reversible transformation is an elementary transformation of the or combination of elementary transformations, selected from the group including:
building image, unencrypted symmetric image with respect to an axis parallel to the edge of the image;
the permutation of blocks of pixels unencrypted image and
adding offset values to the color of at least one of the pixel block non-encrypted image.

4. The method according to claim 1, in which the secret reversible transformation is arranged to convert an unencrypted stream of images in the converted stream of images containing the same number of pieces of information of each image, and an unencrypted stream of images.

5. The method according to claim 1, additionally containing a phase in which change secret reversible transformation at set intervals or on command.

6. The method according to claim 5, additionally containing a phase in which passed (118) message containing the cryptogram, providing the possibility of finding a host device invertible transformations used to restore the unencrypted stream of images from the converted stream of images.

7. The method according to claim 6, which additionally contains the phase in which the insert (110) message in the converted stream of images before encoding to transmit a message simultaneously with the flow of the image is ageny.

8. The method according to any one of claims 1 to 7, optionally containing phase in which scrambling compressed stream of images before sending.

9. How to display a stream of images received by the method according to any one of claims 1 to 8, comprising stages, which are:
accept (120) stream of images and
decode (126) adopted a stream of images to obtain a decompressed stream of images
after decoding the stream of images are preprocessed (136) via callback used when sending sensitive to image conversion the converted stream is converted images to receive the stream of images in an unencrypted form and then display thus obtained stream of images.

10. The recording media data, characterized in that it includes instructions, when executed in the electronic computer executes the method according to any one of claims 1 to 9.

11. The transfer device and the flow of images in an unencrypted form, containing:
encoder (16) of the stream of images to produce a compressed stream of images and
the transmitter compressed stream of images, at least one receiving device,
the device contains a module (30) conversion with convert images unencrypted stream of images through the secret of the CSOs reversible transform to obtain a transformed stream of images, encoded and transmitted instead of the unencrypted stream of images, and the secret reversible conversion converts each image of a sequence of unencrypted image:
by the same permutation of the positions of pixels for each image of the sequence unencrypted images and/or
by the same changes of colors of pixels for each image of the sequence unencrypted images so that the change applied to each unencrypted image directly perceived by a person when displaying the converted image on the screen without first applying the inverse transform.

12. Module (88) the inverse transform for the implementation of the display method according to claim 9, characterized in that the module is made with the possibility of transformation through back used when sending sensitive to convert the images of the converted stream to obtain a stream unencrypted images.



 

Same patents:

FIELD: radio engineering, communication.

SUBSTANCE: device and method are proposed to transfer a preamble in a DVB system, at the same time the device comprises: the first processor for generation of a modulation signalling sequence (MSS) with application of multiple received sequences and for production of a modulated sequence by means of differential modulation MSS; a scrambling module for scrambling of a modulated sequence by multiplication of a modulated sequence by a sequence of scrambling, and the second processor receives a scrambled sequence via each dedicated subcarrier, converts the received sequence into a signal of time domain and generates and transfers a preamble.

EFFECT: reduced ratio of peak power to average capacity of a preamble by means of scrambling.

27 cl, 10 dwg, 5 tbl

FIELD: information technologies.

SUBSTANCE: device (3400) for processing of coded data flow (3401), comprising a decoding module (3402) to generate decoded data flow (3403) from coded data flow (3401), detection module (3404) for detection of information on position of at least one intra-coded frame in coded data flow (3403) and substitution module (3405) for substitution on the basis of detected information on position of coded data flow (3401) parts with according parts of decoded data flow (3403).

EFFECT: increased efficiency, speed of data flow processing by means of selective substitution of only that data in data flow, which is required for further use of data flow.

28 cl, 37 dwg

FIELD: method and systems for injecting command into device being controlled.

SUBSTANCE: in accordance to method, watermark is formed, containing inbuilt control command, which should be executed by device being controlled, control command being related to representation of advertisement, signal is generated, containing watermark, inbuilt in information block represented by it and transferred into device being controlled, generated signal is transferred with watermark into device being controlled for showing advertisement to user by executing control command, related to showing advertisement, user is questioned to determine his preferences and on basis of questioning user profile is generated with consideration of sales data for devices being controlled, product identification is added to control command, while control command contains value of parameter, specific for advertisement, while device being controlled receives advertisement, wherein parameter values are used.

EFFECT: creation of method and system for injecting command into device being controlled, wherein direct transfer of command into device is provided.

3 cl, 4 dwg

FIELD: data signals.

SUBSTANCE: additional data are encoded in relative position or phase of one or more water signs, which allows insertion of multi-bit data, while using only one or several certain water signs.

EFFECT: higher efficiency.

6 cl, 10 dwg, 2 tbl

The invention relates to a method and apparatus for recording the scrambled data, such as broadcast television

The hidden sign // 2222114
The invention relates to a method for detecting a hidden symbol in the information signal, which may have been marked by modifying the values of the information signal in accordance with the corresponding values of the picture hidden sign

The invention relates to the field of audio and video for advanced services in cable television, direct satellite broadcasting or the Internet

The invention relates to a method for cancellation of removal or reduction action signal protection videocapture

The invention relates to the protection of footage from copying by putting a video of sustainable identification codes

FIELD: information technology.

SUBSTANCE: method of compressing images programmed in a controller of a device, comprising: partitioning an image into one or more blocks; applying gamma conversion to each pixel of the image to generate data with the same number of bits; computing prediction values for each pixel in each block of the one or more blocks using a plurality of prediction modes; applying quantisation to each pixel of each block of the one or more blocks using a plurality of quantisation numbers; computing differential pulse code modulation (DPCM) to generate residuals of the quantised values for each of the plurality of quantisation numbers, wherein the number of bits generated for each block of the one or more blocks is equal to the bit budget; computing pulse code modulation (PCM), which includes shifting each pixel value by a fixed number of bits; selecting for each block of said one or more blocks, DPCM with a quantisation number where the best quantisation accuracy is achieved; selecting an encoding method from the DPCM with said quantisation number and PCM; and generating a bit stream containing data encoded using the selected encoding method.

EFFECT: compression without visual losses.

14 cl, 17 dwg

FIELD: physics, computer engineering.

SUBSTANCE: invention relates to means of digitising a frame image.

EFFECT: frame digitisation with not three converters in each matrix element but with one converter in each matrix element which, during the frame period, concurrently and synchronously performs three successive conversions of colours R, G, B with 15 bits each, and image digitisation ends at the end of the frame period.

4 dwg

FIELD: information technology.

SUBSTANCE: image compression method, based on excluding a certain portion of information, wherein the information is excluded from the space domain through numerical solution of Poisson or Laplace differential equations, and subsequent estimation of the difference between the obtained solution and actual values at discrete points of the image; generating an array of boundary conditions, which includes a considerable number of equal elements which is compressed, and the image is reconstructed by solving Poisson or Laplace partial differential equations using the array of boundary conditions.

EFFECT: eliminating loss of image integrity, high efficiency of compressing images having large areas of the same tone or gradient and maintaining contrast of boundaries between different objects of an image.

2 cl, 16 dwg

FIELD: information technology.

SUBSTANCE: method is carried out by realising automatic computer formation of a prediction procedure which is appropriately applied to an input image. The technical result is achieved by making an image encoding device for encoding images using a predicted pixel value generated by a predetermined procedure for generating a predicted value which predicts the value of a target encoding pixel using a pre-decoded pixel. The procedure for generating a predicted value, having the best estimate cost, is selected from procedures for generating a predicted value as parents and descendants, where the overall information content for displaying a tree structure and volume of code estimated by the predicted pixel value, obtained through the tree structure, is used as an estimate cost. The final procedure for generating a predicted value is formed by repeating the relevant operation.

EFFECT: high efficiency of encoding and decoding, and further reduction of the relevant volume of code.

12 cl, 14 dwg

FIELD: information technologies.

SUBSTANCE: in the method of processing of raster images, including compression of an image by the method of "cut block coding" or its modifications, before the procedure of compressing coding they perform digital filtration, which increases sharpness of the compressed image, and after the decoding procedure they perform smoothing digital filtration of the decoded image.

EFFECT: improved quality of decoded raster images when methods used for their compressing coding on the basis of cut block coding or their modifications, improved current formalised criteria.

3 cl, 8 dwg

FIELD: radio engineering, communication.

SUBSTANCE: method of encoding transform coefficients includes: encoding the position and value of a last non-zero coefficient of a block; encoding at least one coefficient in accordance with a first coding mode if the amplitude of said at least one coefficient is less than or equal to a threshold; and determining a cumulative sum of amplitudes of previously coded non-zero coefficients that are greater than the threshold; and if the cumulative sum is less than a cumulative threshold value, and the position of the last non-zero coefficient is less than a location threshold: coding a subsequent coefficient in accordance with the first coding mode; otherwise, coding a subsequent coefficient in accordance with a second coding mode.

EFFECT: high encoding efficiency.

22 cl, 8 dwg

FIELD: information technology.

SUBSTANCE: methods and systems for processing document object models (DOM) and processing video content are provided. Information content which is represented by a DOM and which includes a scripting language associated with the information content is received and original content of the DOM is stored after execution of the scripting language. Further, video content is adapted for client devices. The scripting language associated with the information content can be sent to client device along with a modified DOM and processed video content. Pre-processing of the scripting language is carried out to identify nodes related to video content and to maintain all other original nodes, for example.

EFFECT: easier processing of video data.

23 cl, 12 dwg

Video camera // 2473968

FIELD: information technology.

SUBSTANCE: video camera has a portable housing having a light focusing lens, a light-sensitive device which converts the focused light into source video data, a storage device installed in the housing, and an image processing system configured to introduce predistortions into the source video data and compression thereof, wherein the compressed source video data remain essentially visual without loss after decompression, and also configured to store compressed source video data in the storage device.

EFFECT: reduced loss of quality of a compressed image during decompression and display.

22 cl, 18 dwg

FIELD: information technologies.

SUBSTANCE: device comprises a processor arranged as capable of realisation of a set of commands for calling a facility of intracycle filtration of blocking effect deletion and for universal correction of blocking effect in a decoded output signal during operation of a post-cycle filtration using the facility of intracycle filtration of blocking effect deletion, at the same time the universal correction of blocking effect includes the following: performance of an operation of strong filtration in respect to units in a decoded output signal for correction of an inherited blocking effect, at the same time units contain missed macrounits and units with a template of a coded unit, equal to zero, and inclusion of a facility of intracycle filtration of blocking effect removal for edges of a fragment of an image of fixed size, which are not arranged on the border of the unit of the appropriate intermediate macrounit, for correction of the inherited blocking effect; and a memory connected to the processor.

EFFECT: development of a method of universal correction of blocking effect, including inherited blocking effect.

19 cl, 23 dwg, 7 tbl

Virtual code window // 2463662

FIELD: information technology.

SUBSTANCE: method of encoding a graphic display to provide a unique, distinctive machine-readable code for a plurality of commodities involves obtaining an image of part of the graphic display. An electronic image of the temporary boundary around a certain part of the graphic display is formed relative a fixed trigger point. Part of the obtained image lying inside that boundary is processed to obtain a descriptor. Data are assigned to the descriptor. Further, that relationship is stored in a storage. The graphic display is fixed for a plurality of commodities and the temporary boundary is different for each commodity such that part of the graphic display which forms the code is different for each commodity.

EFFECT: high protection from copying, forgery or unauthorised reading of a graphic code.

7 cl, 10 dwg

FIELD: systems for encoding and decoding video signals.

SUBSTANCE: method and system for statistical encoding are claimed, where parameters which represent the encoded signal are transformed to indexes of code words, so that decoder may restore the encoded signal from aforementioned indexes of code words. When the parameter space is limited in such a way that encoding becomes inefficient and code words are not positioned in ordered or continuous fashion in accordance with parameters, sorting is used to sort parameters into various groups with the goal of transformation of parameters from various groups into indexes of code words in different manner, so that assignment of code word indexes which correspond to parameters is performed in continuous and ordered fashion. Sorting may be based on absolute values of parameters relatively to selected value. In process of decoding, indexes of code words are also sorted into various groups on basis of code word index values relatively to selected value.

EFFECT: increased efficiency of compression, when encoding parameters are within limited range to ensure ordered transformation of code word indexes.

6 cl, 3 dwg

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