Embedded zerotree wavelets coding based on adaptive fuzzy clustering for image compression
Image and Vision Computing
Down-sampling design in DCT domain with arbitrary ratio for image/video transcoding
IEEE Transactions on Image Processing
Low bit-rate image compression via adaptive down-sampling and constrained least squares upconversion
IEEE Transactions on Image Processing
Perception Based Down Sampling for Low Bit Rate Image Coding
PCM '09 Proceedings of the 10th Pacific Rim Conference on Multimedia: Advances in Multimedia Information Processing
Adaptive DCT-Domain Down-Sampling and Learning Based Mapping for Low Bit-Rate Image Compression
PCM '09 Proceedings of the 10th Pacific Rim Conference on Multimedia: Advances in Multimedia Information Processing
Block Adaptive Super Resolution Video Coding
PCM '09 Proceedings of the 10th Pacific Rim Conference on Multimedia: Advances in Multimedia Information Processing
Image compression with downsampling and overlapped transform at low bit rates
ICIP'09 Proceedings of the 16th IEEE international conference on Image processing
Evaluating quality and comprehension of real-time sign language video on mobile phones
The proceedings of the 13th international ACM SIGACCESS conference on Computers and accessibility
Sparse representation based down-sampling image compression
Journal of Computational and Applied Mathematics
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At low bit rates, better coding quality can be achieved by downsampling the image prior to compression and estimating the missing portion after decompression. This paper presents a new algorithm in such a paradigm, based on the adaptive decision of appropriate downsampling directions/ratios and quantization steps, in order to achieve higher coding quality with low bit rates with the consideration of local visual significance. The full-resolution image can be restored from the DCT coefficients of the downsampled pixels so that the spatial interpolation required otherwise is avoided. The proposed algorithm significantly raises the critical bit rate to approximately 1.2 bpp, from 0.15-0.41 bpp in the existing downsample-prior-to-JPEG schemes and, therefore, outperforms the standard JPEG method in a much wider bit-rate scope. The experiments have demonstrated better PSNR improvement over the existing techniques before the critical bit rate. In addition, the adaptive mode decision not only makes the critical bit rate less image-independent, but also automates the switching coders in variable bit-rate applications, since the algorithm turns to the standard JPEG method whenever it is necessary at higher bit rates