Iterative Frame Decimation and Watermarking for  Human Motion Animation   Shiyu Li, Masahiro Okuda Faculty of Environmenta...
PRELIMINARY Body Skeleton Configuration root terminator end effector link
Introduction-  Why Motion Coding ? <ul><li>Reuse motion data (storing) </li></ul><ul><li>Motion data retrieval </li></ul><...
Introduction-   Two methods <ul><li>Reduce motion sample density </li></ul><ul><li>-key-frame, interpolation </li></ul><ul...
Reduce motion sample density <ul><li>key-framing </li></ul><ul><li>Shiyu Li, Masahiro Okuda and Shin-ichi Takahashi, “ Emb...
Reduce size of database <ul><li>Wavelet transform based </li></ul><ul><li>Shiyu Li, Masahiro Okuda, Shin-ichi Takahashi, “...
Embedded Key-frame Extraction for CG Animation by Frame Decimation <ul><li>Previous method: motion curve simplification </...
Watermark for Progressive Human Motion Animation <ul><li>A progressive coding based watermarking scheme </li></ul>To embed...
Hierarchical Human Motion Compression with Constraints on Frames Data Compensation for joint i+ 1 Input : joint  i Wavelet...
Kinematics-based motion compression for human figure animation Endcoder  Decoder Entropy decoding dequantization Position ...
Upcoming SlideShare
Loading in …5
×

Iterative Frame Decimation and Watermarking for Human Motion Animation

559 views

Published on

Iterative Frame Decimation and Watermarking for Human Motion Animation

Shiyu Li and Masahiro Okuda

Faculty of Environmental Engineering, The University of Kitakyushu, 1-1, Hibikino, Wakamatsu-ku, Kitakyushu, Fukuoka, Japan

  • Be the first to comment

  • Be the first to like this

Iterative Frame Decimation and Watermarking for Human Motion Animation

  1. 1. Iterative Frame Decimation and Watermarking for Human Motion Animation Shiyu Li, Masahiro Okuda Faculty of Environmental Engineering, The University of Kitakyushu 1-1,Hibikino, Wakamatsu-ku, Kitakyushu, Fukuoka, Japan [lishiyu, okuda-m]@env.kitakyu-u.ac.jp http://vig.is.env.kitakyu-u.ac.jp/
  2. 2. PRELIMINARY Body Skeleton Configuration root terminator end effector link
  3. 3. Introduction- Why Motion Coding ? <ul><li>Reuse motion data (storing) </li></ul><ul><li>Motion data retrieval </li></ul><ul><li>Motion editing </li></ul><ul><li>Real time transmitting </li></ul>
  4. 4. Introduction- Two methods <ul><li>Reduce motion sample density </li></ul><ul><li>-key-frame, interpolation </li></ul><ul><li>Reduce size of database </li></ul><ul><li>-compression of each sample itself </li></ul>
  5. 5. Reduce motion sample density <ul><li>key-framing </li></ul><ul><li>Shiyu Li, Masahiro Okuda and Shin-ichi Takahashi, “ Embedded Key-frame Extraction for CG Animation by Frame Decimation ”, Proceed­ing of IEEE Int. Conference on Multimedia & Expo (ICME05) </li></ul><ul><li>Watermarking </li></ul><ul><li>Shiyu Li, Masahiro Okuda, “ Watermark for Progressive Human Motion Animation ”, Proceed­ing of IEEE Int. Conference on Multimedia & Expo (ICME07) </li></ul>
  6. 6. Reduce size of database <ul><li>Wavelet transform based </li></ul><ul><li>Shiyu Li, Masahiro Okuda, Shin-ichi Takahashi, “ Hierarchical Human Motion Compression with Constraints on Frames ”, 47th MWSCAS, Hiroshima, Japan, pp. I-253- I-256, Jul. 2004. </li></ul><ul><li>Using the Reduction of Inter-Joint Correlation </li></ul><ul><li>Shiyu Li, Masahiro Okuda, Shin-ichi Takahashi, “ Kinematics-based motion compression for human figure animation ”, 30th ICASSP, Pennsylvania, United States, vol.II, pp.1077-1080, Mar. 2005. </li></ul>
  7. 7. Embedded Key-frame Extraction for CG Animation by Frame Decimation <ul><li>Previous method: motion curve simplification </li></ul><ul><li>Our method: All the frames are ranked by their importance, and thus users can specify any number of key-frames from one data set. </li></ul>
  8. 8. Watermark for Progressive Human Motion Animation <ul><li>A progressive coding based watermarking scheme </li></ul>To embed the watermark in the encoder: The sequence E is broken up into blocks. We use 50 frames per block. To calculate the variance Var(E) of the signal E in each block: (1). if the value of a frame is larger than Et , Et is subtracted from this frame. Fig.2(b) represents the signal after this preprocessing. (2). to produce a sequence which is zero-mean, the mean of each block is subtracted from each frame. Calculate the variance Var(E) of each block. Calculate the variance Var( w ) of the watermark w by the Var(E) . Generate a pseudo random sequence w with the same length as the blocks of sequence E , assume E and w are independent. See Fig2.(c) Store E’ = E+ w as the watermarked signal. See Fig2.(d) The watermarked signal E’ is sent to the decoder. In the decoder: Rank the frames by the value of E’ . R eceive the key-frames progressively as this order. After applying interpolation to the key-frames, the motion can be reconstructed approximatively. To detect if the watermark exists , the original Et is necessary : Calculate the variance of E’ after the same preprocessing in the encoder, i.e. if the value of a frame is larger than Et , Et is subtracted from this frame. Estimate the variance of w, assuming Var(E’)=Var(E) +Var( w ) . Var(E) is calculated by the same method in step1. Regenerate w using the same seed value. Calculate Z=Σ(w* E’) Declare E’ watermarked if Z > n Var( w ) / 2
  9. 9. Hierarchical Human Motion Compression with Constraints on Frames Data Compensation for joint i+ 1 Input : joint i Wavelet Transform: c 0 ,w 0 ,w 1 ,...,w j -1 ,c j -1 Max-Shift for Constraint frames (Scale up) Entropy Coding Hierarchical Quantization Dequantization Hierarchically Inverse Operation (Decoder) Inverse Wavelet Transform: c 0 ,w 0 ,w 1 ,...,w j -1 ,c j -1 Max-Shift for Constraint frames (Scale down) Entropy Decoding Input bits Convert to Euler- angle format Output : joint i Convert to two- angle format Output bits Encoder Decoder
  10. 10. Kinematics-based motion compression for human figure animation Endcoder Decoder Entropy decoding dequantization Position calculation Prediction by IK Compressed   angles of previous frame Converted Two angles Angle conversion Bits of end- effectors Entropy decoding dequantization Convert all joints to original angle format Bits of general other joints Orientation Angle retrieval General other joints Position calculation quantization Entropy coding decoding Com- pressed position Prediction by IK Calculate prediction error quantization decoding End effectors Simple prediction Compressed   angles of previous frame Orientation calculation Entropy coding Simple prediction Converted format

×