In this paper, we propose perceptual activity measures, which are computed from weighted transforms of the block, to precisely estimate the sensitivity of blocks. From analysis of principal components of a referred background region, we first suggest a weighted Karhunen-Loeve transformation (KLT) activity measure to characterize the visual variation of the image block. The weighted KLT computed in block-by-block fashions requires large computational complexity. To reduce the computation, we further utilize the first-order Markov's model and discrete cosine transform (DCT) to derive a simplified perceptual activity measure. Simulated results show that the proposed measures achieving precise visual perception can be effectively utilized in many block-based image and video compression systems.
All Science Journal Classification (ASJC) codes
- Control and Systems Engineering
- Signal Processing
- Computer Vision and Pattern Recognition
- Electrical and Electronic Engineering