Perceptual Quantization for Wavelet-Based Image Coding
نویسندگان
چکیده
A psychovisually-based quantization strategy for wavelet coded images is proposed. The quantization strategy is based on the results of a psychovisual evaluation to quantify sensitivities to suprathreshold distortion caused by wavelet coefficient quantization in natural images. Quantizer step sizes to produce a minimum noticeable distortion are paremeterized in terms of subband standard deviation and a quantization strategy is subsequentely proposed. The resulting strategy is applied to both intraband and embedded wavelet coders and reveals a significant perceptual improvement when images exhibit supra-threshold distortion.
منابع مشابه
Wavelet-based image compression using perceptual distortion metric
In this paper, we have implemented a dithered quantization model to be used with perceptual distortion metric. Mean-square-error (MSE) based cost functions are mostly used for image coding. However, MSE does not necessarily preserve the perceptual quality of the original image. We are using Minkowsky metric as the criterion for allocating bits into various subbands to achieve desired degree of ...
متن کاملMuliresolution, Adaptive Vector Quantization and Perceptual Based Multiview Image Codec
This paper presents a multiresolution adaptive vector quantization and perceptual based multiview image coding scheme. It decorrelates the input views into a number of subbands using a lifting based wavelet transform. The coefficients in the same subbands of different views are divided into vectors and then joined together. The resulting vectors are then vector quantized using an adaptive vecto...
متن کاملUniversal trellis coded quantization
A new form of trellis coded quantization based on uniform quantization thresholds and "on-the-fly" quantizer training is presented. The universal trellis coded quantization (UTCQ) technique requires neither stored codebooks nor a computationally intense codebook design algorithm. Its performance is comparable with that of fully optimized entropy-constrained trellis coded quantization (ECTCQ) fo...
متن کاملIntelligent scalable image watermarking robust against progressive DWT-based compression using genetic algorithms
Image watermarking refers to the process of embedding an authentication message, called watermark, into the host image to uniquely identify the ownership. In this paper a novel, intelligent, scalable, robust wavelet-based watermarking approach is proposed. The proposed approach employs a genetic algorithm to find nearly optimal positions to insert watermark. The embedding positions coded as chr...
متن کاملPerceptual Image Compression Using Jpeg2000
Image sizes have increased exponentially in recent years. The resulting highresolution images are typically encoded in a lossy fashion to achieve high compression ratios. Lossy compression can be categorized into visually lossless and visually lossy compression depending on the visibility of compression artifacts. This dissertation proposes visually lossless coding methods as well as a visually...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2000