An overview of quantization in JPEG 2000

Maximum Likelihood Estimation of JPEG Quantization Table in the Identification of Bitmap Compression History

To process previously JPEG coded images the knowledge of the quantization table used in compression is sometimes required. This happens for example in JPEG artifact removal and in JPEG re-compression. However, the quantization table might not be known due to various reasons. In this paper, a method is presented for the maximum likelihood estimation (MLE) of the JPEG quantization tables. An effi...

Implementation of ROI Based Baseline Sequential Adaptive Quantization

The JPEG[1] (Joint Photographic Experts Group) introduced a still image graphics format in 1987, known as JPEG. The process flow in the baseline mode, converts color images to 8x8 block based DCT mostly applied for gray images, then we applied quantization for the DCT in zigzag ordering, and obtained entropy coding using Huffman tables in the encoding process is obtained and vice versa for deco...

Fixed Length Coding by Nonuniform Scalar Quantization in JPEG 2000

VISUALLY LOSSLESS CODING FOR COLOR AERIAL IMAGES USING JPEG 2000 Graduate Students :

This paper describes a psychophysical experiment to measure visibility thresholds (VT) for quantization distortion in JPEG2000 and an associated quantization algorithm for visually lossless coding of color aerial images. The visibility thresholds are obtained from a quantization distortion model based on the statistical characteristics of wavelet coefficients and the deadzone quantizer of JPEG2...

Still image compression method based on adaptive block segmentation vector quantization technique

In order to increase the performance of image compression by Vector Quantization (VQ), we have developed a new still image compression algorithm. Adaptive block segmentation vector quantization (ABSVQ) method, which is composed of three key techniques, i.e., the resolution conversion, the quad tree data structure and the Mean-Residual VQ, can realize much superior compression performance than t...