JPEG 2000: Image Compression Fundamentals, Standards and Practice
JPEG 2000: Image Compression Fundamentals, Standards and Practice
The application of symmetric orthogonal multiwavelets and prefilter technique for image compression
Multimedia Tools and Applications
Adaptive Transform Coefficient Scan for H.264 Intra Coding
IEICE - Transactions on Information and Systems
IEEE Transactions on Signal Processing
Suboptimality of the Karhunen-Loeve transform for transform coding
IEEE Transactions on Information Theory
The H.264/MPEG4 advanced video coding standard and its applications
IEEE Communications Magazine
IEEE Transactions on Image Processing
Peak Transform for Efficient Image Representation and Coding
IEEE Transactions on Image Processing
The MPEG-4 video standard verification model
IEEE Transactions on Circuits and Systems for Video Technology
Overview of the H.264/AVC video coding standard
IEEE Transactions on Circuits and Systems for Video Technology
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In H.264/AVC, 4 脳 4 discrete cosine transform (DCT) is performed on the residual signals after intra prediction for decorrelation. Actually, residual blocks with different prediction modes exhibit different frequency characteristics. Therefore, the fixed transform matrix cannot match the energetic distribution of residual signals very well, which degrades the decorrelation performance. Fortunately, the energetic distributions of residual blocks with the same mode are relatively coincident, which makes it possible to train a universally good Karhunen---Loève transform (KLT) matrix for each mode. In this paper, an optimal frequency matching (OFM) algorithm is proposed to train KLT matrices for residual blocks and nine KLT matrices corresponding to nine prediction modes of 4 脳 4 intra blocks are trained. Experimental results show that KLT with trained matrices yields a persistent gain over H.264 using 4 脳 4 DCT with an average peak signal-to-noise ratio (PSNR) enhancement of 0.22dB and a maximum enhancement of 0.33dB.