Research Article
Improving Anticompression Robustness of JPEG Adaptive Steganography Based on Robustness Measurement and DCT Block Selection
Algorithm 1
Cover block selection algorithm.
| | Input: JPEG cover image , elementwise classic cost , blockwise transmission cost | | | Output: cover selection indicator | | (1) | For each DCT block in do | | (2) | forto 64 do // elementwise | | (3) | | | (4) | end | | (5) | // blockwise | | (6) | | | (7) | ifthen // update | | (8) | | | (9) | end | | (10) | | | (11) | // joint cost | | (12) | end | | (13) | expection_cost | | (14) | expection_cost_r | | (15) | for each in do | | (16) | expection_cost_c | | (17) | expection_cost_r | | | // calculate gain function | | (18) | | | (19) | end | | (20) | // suboptimal | | (21) | block_selection (threshold) |
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