Perceptual approaches have been widely used in many areas of visual information processing. This paper presents an overview of perceptual based approaches for image enhancement, segmentation and coding. The paper also provides a brief review of image quality assessment (IQA) methods, which are used to evaluate the performance of visual information processing techniques. The intent of this paper...

Region-of-Interest (ROI) techniques are often utilized in natural stillimage coding standards such as JPEG2000 [1]. In contrast, document image coding typically adopts multi-layer methods [2], using a carefully selected algorithm for each layer to optimize overall performance. In this paper, an ROI-based method is proposed for multi-component document image coding, where rectangular textual ROI...

The information gathering capacity of the visual system can be specified in units of bits/mm2. The fall-off in sensitivity of the human visual system at high spatial frequencies allows a reduction in the bits/mm2 needed to specify an image. A variety of compression schemes attempt to achieve a further reduction in the number of bit/mm2 while maintaining perceptual losslessness. This paper makes...

Resumo: Based on a human visual system (HVS) based approach, digital video image quality and perceptual coding (DVIQPC) outlines the principles, metrics an standards associated with perceptual coding as well as the latest techniques and applications. It discusses the latest developments in vision research as they relate to HVS based video and image coding. It discusses subjective and objective ...

This paper presents a perceptual-based image coder, which discriminates between image components based on their perceptual relevance for achieving increased performance in terms of quality and bit-rate. The new coder uses a locally-adaptive perceptual quantization scheme based on a tractable perceptual distortion metric. Our strategy is to exploit human visual masking properties by deriving vis...

Importance prioritised coding is a principle aimed at improving the interpretability (or image content recognition) versus bit-rate performance of image coding systems. This can be achieved by (1) detecting and tracking image content or regions of interest (ROI) that are crucial to the interpretation of an image, and (2) compressing them in such a manner that enables ROIs to be encoded with hig...

We propose in this paper an introduction to the wavefront coding technique for incoherent imaging. Wavefront coding introduces image processing in the conception of an imaging system. It consists in introducing controlled aberrations in the optics able to reduce, after processing, some defaults of the optical system such as defocus, chromaticity. We present the basis of wavefront coding and ill...

In this paper, we propose a novel method called DHSED to hide binary visual patterns in two error diffused halftone images. While one halftone image is only a regular error diffused image, stochastic error diffusion is applied to the other image to generate special stochastic characteristics with respect to the first image such that the visual pattern would appear when the two halftone images a...

A large part of classical visual psychophysics was concerned with the fundamental question of how pattern information is initially encoded in the human visual system. From these studies a relatively standard model of early spatial vision emerged, based on spatial frequency and orientation-specific channels followed by an accelerating nonlinearity and divisive normalization: contrast gain-contro...

New breakthroughs in image coding possibly rely in signal decomposition through non-separable basis functions. The work proposed in this paper provides an adaptive way of representing images as a sum of two-dimensional features. It presents a low bit-rate image coding method based on a Matching Pursuit expansion, over a dictionary built on anisotropic refinement and rotation of contour-like ato...