Research Article
Coverless Steganography Based on Motion Analysis of Video
Algorithm 1
Index database construction.
| | Input: video database , number of videos d, smoothing window size for optical flow calculation W, number of LK pyramid level L, and bin number N. | | | Output: video index database | | (1) | For i = 1: d | | (2) | Decompose video to pictures: P = VideoToFrame (Vi) | | (3) | For j = 1: FrameNum-1 | | (4) | Convert RGB to gray: Rj = Rgb2gray (Pj), Rj+1 = Rgb2gray (Pj+1) | | (5) | Median filtering: Mj = medfilt (Rj), Mj+1 = medfilt (Rj+1), | | (6) | Calculate the hierarchical optical flow matrixes between frame j and j + 1: (u, ) = HierarchicalLK (Mj,Mj+1, W, L) | | (7) | Calculate RHOOF and hash sequences in subblocks | | | For s = 1: subblock_num | | (8) | H s = RHOOF (u, , N) | | (9) | Hashs = HashCalc (Hs) | | (10) | Link MySQL and update index database: index item-> {index ID, video ID, frame ID, subblock ID} | | (11) | End for | | (12) | End for | | (13) | End for |
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