Quality Degradation in Lossy Wavelet Image Compression

Eecient Context-based Entropy Coding for Lossy Wavelet Image Compression

In this paper we present an adaptive image coding algorithm based on novel backwardadaptive quantization/classi cation techniques. We use a simple uniform scalar quantizer to quantize the image subbands. Our algorithm puts each coe cient into one of several classes depending on the values of neighboring previously quantized coe cients. These previously quantized coe cients form contexts which a...

Efficient Context-Based Entropy Coding Lossy Wavelet Image Compression

Lossy Image Compression Using Discrete Wavelet Transform and Thresholding Techniques

Results of lossy image compression using wavelet transforms and several thresholding techniques are presented here. The analyzed image was divided into little sub-images and each one was decomposed in a vector following a Hilbert fractal curve. The wavelet transform was applied to each vector and some of the high frequency components were suppressed based on some threshold criteria. Different l...

Integer wavelet transform for embedded lossy to lossless image compression

The use of the discrete wavelet transform (DWT) for embedded lossy image compression is now well established. One of the possible implementations of the DWT is the lifting scheme (LS). Because perfect reconstruction is granted by the structure of the LS, nonlinear transforms can be used, allowing efficient lossless compression as well. The integer wavelet transform (IWT) is one of them. This is...

Lossy and Lossless Image Compression using Reversible Integer Wavelet Transforms

Comparison of the lossless compression performances of diierent integer wavelet transforms on other images (in bpp).