New image coding and reconstruction algorithm based on all phase bi-orthogonal Tchebichef transform
Changzhen Xiong · Journal of Communications · 2010
In order to overcome the shortcomings that the JPEG quantization table is not easy to design and the blocking effect of reconstructed image based on low bit rate JPEG compression is hard to remove,an all phase bi-orthogonal transform based on tchebichef system(APBTT) was constructed.This method combined the good data approximation performance of the complete orthogonal Tchebichef system and the zero phase characteristics of the all phase digital filter.Then by using APBTT matrix,a low bit rate image coding and reconstruction algorithm was proposed.The proposed im-age coding and reconstruction algorithm used uniform quantization intervals to quantify the coefficients obtained by APBTT.This method did not need the quantization table.The approach simplified and speeded the process of the image coding.The blocking effect of reconstructed image by APBTT could be removed effectively by smoothing the pixels on the borderline of blocks or the whole image with an averaging filter.The proposed method outperforms DCT-JPEG algo-rithm in image quality and coding speed.The new method is suitable for low bit rate image compression.