Color Image Compression Based on Wavelet, Differential Pulse Code Modulation and Quadtree Coding
Ali Husain Ahmed, Loay Edwar George · Research Journal of Applied Sciences Engineering and Technology · 2017
The objective of this study is to introduce a low cost color image lossy color image compression. The RGB image data is transformed to YUV color space, then the chromatic bands U&V are down-sampled using dissemination step. The bi-orthogonal wavelet transform is used to decompose each color sub band, separately. Then, the Differential Pulse-Code Modulation (DPCM) is used to encode the Low-Low (LL) sub band. The other wavelet sub bands are coded using scalar Quantization. Also, the quad-tree coding process is applied on the outcomes of DPCM and quantization processes. Finally, the adaptive shift coding is applied as high order entropy encoder to remove the remaining statistical redundancy to achieve good efficiency in the performance of the compression process. The introduced system was applied on a set of standard color image; the attained compression results indicated good efficiency in terms of compression gain while keeping the fidelity level above the acceptable level.