发明名称 |
METHOD FOR PROVIDING FIXED OR ANIMATED IMAGES WITH ACCESS CONTROL |
摘要 |
The invention concerns a method for an access control transmission of at least an image which has been subjected to a DCT transformation. The invention is characterized in that it consists in: prior to transmission, in partly degrading the quality of the image by scrambling by modifying part of the values of the predefined quantization table (8); swapping the DCT coefficients of a predetermined group (12) of DCT coefficients; transmitting access control data and the modified quantization table with the scrambled image; at reception, retrieving the access control data, and if access is granted; then restoring the predefined quantization table (8); inversely swapping the previously swapped DCT coefficients; otherwise delivering the scrambled image. |
申请公布号 |
WO03043304(A3) |
申请公布日期 |
2004.04.08 |
申请号 |
WO2002FR03860 |
申请日期 |
2002.11.12 |
申请人 |
FRANCE TELECOM;MORLET, JEAN-NOEL |
发明人 |
MORLET, JEAN-NOEL |
分类号 |
H04N7/167;H04N7/26;H04N7/30 |
主分类号 |
H04N7/167 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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