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US 2004/0177251 A1Published application
Image data encryption method, image data transform method, apparatus for the methods, computer program, and computer-readable storage medium
AssigneeCanon Kabushiki Kaisha
InventorJunichi Hayashi
Life of this patent
Estimating the term…
Abstract
This invention allows the encryption side to set whether an image playback apparatus should play back image data in a scrambled state or a non-scrambled state. When a code-block of input image data is an object to be encrypted, it is encrypted. In playing back the data, it is determined whether playback is to be executed by using the encrypted code-block (the scrambling playback mode is to be set). To inhibit use of the encrypted code-block, a terminating marker is placed at the start of the code-block. To use the encrypted code-block, the terminating marker is placed at the end of the code-block.
Claims28
An image data encryption method of encrypting image data, comprising:
- a step of inputting image data, which is constituted by a plurality of data blocks, for each data block;
- a determination step of determining whether the input data block is an object to be encrypted;
- an encryption step of encrypting the data block when it is determined in the determination step that the data block as the object to be encrypted is input;
- an addition step of adding terminating information to specify a terminating position of significant data for decoding to a start position of the data block encrypted in the encryption step;
- a switching step of switching whether the addition step should be executed;
- and
- an output step of outputting a data block which is determined in the determination step as a data block not to be encrypted and a data block generated via the switching step.
4 more elements
An image data conversion method of converting image data containing encrypted data for playback processing, comprising:
- a step of inputting image data, which is constituted by a plurality of data blocks, for each data block;
- a first determination step of determining whether the input data block is encrypted;
- a second determination step of, when it is determined in the first determination step that the data block is encrypted, determining whether decryption key information is present;
- a decryption step of, when it is determined in the second determination step that the key information is present, decrypting the input data block in accordance with the key information and, when terminating information to specify a terminating position of significant data is present at a start position of the decrypted data block, invalidating the terminating information;
- and
- an output step of outputting the data block decrypted in the decryption step, a data block which is determined in the first determination step as an unencrypted data block, and a data block for which it is determined in the second determination step that no key information is present.
3 more elements
An image data conversion method of converting image data containing encrypted data for playback processing, comprising:
- a step of inputting image data, which is constituted by a plurality of data blocks, for each data block;
- a first determination step of determining whether the input data block is encrypted;
- a second determination step of, when it is determined in the first determination step that the data block is encrypted, determining whether decryption key information is present;
- a third determination step of, when it is determined in the second determination step that the key information is not present, and terminating information to specify a terminating position of significant data is present at a start position of the input data block, determining whether the terminating information should be invalidated;
- a terminating information invalidation step of, when it is determined in the third determination step that the terminating information should be invalidated, removing the terminating information or placing the terminating information at an end of the data block;
- a decryption step of, when it is determined in the second determination step that the key information is present, decrypting the input data block;
- and
- an output step of outputting a data block which is determined in the first determination step as an unencrypted data block, a data block for which it is determined in the third determination step that the terminating information should not be invalidated, a data block whose terminating information is invalidated in the terminating information invalidation step, and the data block decrypted in the decryption step.
5 more elements
An image data encryption apparatus for encrypting image data, comprising:
- input means for inputting image data, which is constituted by a plurality of data blocks, for each data block;
- determination means for determining whether the input data block is an object to be encrypted;
- encryption means for encrypting the data block when said determination means determines that the data block as the object to be encrypted is input;
- addition means for adding terminating information to specify a terminating position of significant data for decoding to a start position of the data block encrypted by said encryption means;
- switching means for switching whether said addition means should be executed;
- and
- output means for outputting a data block which is determined by said determination means as a data block not to be encrypted and a data block generated via said switching means.
4 more elements
An image data conversion apparatus for converting image data containing encrypted data for playback processing, comprising:
- input means for inputting image data, which is constituted by a plurality of data blocks, for each data block;
- first determination means for determining whether the input data block is encrypted;
- second determination means for, when said first determination means determines that the data block is encrypted, determining whether decryption key information is present;
- decryption means for, when said second determination means determines that the key information is present, decrypting the input data block in accordance with the key information and, when terminating information to specify a terminating position of significant data is present at a start position of the decrypted data block, invalidating the terminating information;
- and
- output means for outputting the data block decrypted by said decryption means, a data block which is determined by said first determination step as an unencrypted data block, and a data block for which it is determined by said second determination means that no key information is present.
3 more elements
An image data conversion apparatus for converting image data containing encrypted data for playback processing, comprising:
- input means for inputting image data, which is constituted by a plurality of data blocks, for each data block;
- first determination means for determining whether the input data block is encrypted;
- second determination means for, when said first determination means determines that the data block is encrypted, determining whether decryption key information is present;
- third determination means for, when said second determination means determines that the key information is not present, and terminating information to specify a terminating position of significant data is present at a start position of the input data block, determining whether the terminating information should be invalidated;
- terminating information invalidation means for, when said third determination means determines that the terminating information should be invalidated, removing the terminating information or placing the terminating information at an end of the data block;
- decryption means for, when said second determination means determines that the key information is present, decrypting the input data block;
- and
- output means for outputting a data block which is determined by said first determination means as an unencrypted data block, a data block for which it is determined by said third determination means that the terminating information should not be invalidated, a data block whose terminating information is invalidated by said terminating information invalidation means, and the data block decrypted by said decryption means.
5 more elements
A computer program which functions as an image data encryption apparatus for encrypting image data, characterized by functioning as:
- input means for inputting image data, which is constituted by a plurality of data blocks, for each data block;
- determination means for determining whether the input data block is an object to be encrypted;
- encryption means for encrypting the data block when said determination means determines that the data block as the object to be encrypted is input;
- addition means for adding terminating information to specify a terminating position of significant data for decoding to a start position of the data block encrypted by said encryption means;
- switching means for switching whether said addition means should be executed;
- and
- output means for outputting a data block which is determined by said determination means as a data block not to be encrypted and a data block generated via said switching means.
4 more elements
A computer program which functions as an image data conversion apparatus for converting image data containing encrypted data for playback processing, characterized by functioning as:
- input means for inputting image data, which is constituted by a plurality of data blocks, for each data block;
- first determination means for determining whether the input data block is encrypted;
- second determination means for, when said first determination means determines that the data block is encrypted, determining whether decryption key information is present;
- decryption means for, when said second determination means determines that the key information is present, decrypting the input data block in accordance with the key information and, when terminating information to specify a terminating position of significant data is present at a start position of the decrypted data block, invalidating the terminating information;
- and
- output means for outputting the data block decrypted by said decryption means, a data block which is determined by said first determination step as an unencrypted data block, and a data block for which it is determined by said second determination means that no key information is present.
3 more elements
A computer program which functions as an image data conversion apparatus for converting image data containing encrypted data for playback processing, characterized by functioning as:
- input means for inputting image data, which is constituted by a plurality of data blocks, for each data block;
- first determination means for determining whether the input data block is encrypted;
- second determination means for, when said first determination means determines that the data block is encrypted, determining whether decryption key information is present;
- third determination means for, when said second determination means determines that the key information is not present, and terminating information to specify a terminating position of significant data is present at a start position of the input data block, determining whether the terminating information should be invalidated;
- terminating information invalidation means for, when said third determination means determines that the terminating information should be invalidated, removing the terminating information or placing the terminating information at an end of the data block;
- decryption means for, when said second determination means determines that the key information is present, decrypting the input data block;
- and
- output means for outputting a data block which is determined by said first determination means as an unencrypted data block, a data block for which it is determined by said third determination means that the terminating information should not be invalidated, a data block whose terminating information is invalidated by said terminating information invalidation means, and the data block decrypted by said decryption means.
5 more elements
Dependencies are inferred from the claim text.