The Retinex theory is used to deal with the removal of unfavorable illumination effects from images. In this paper, we present the Retinex theory for bleeding detection in wireless capsule endoscopy (WCE). This processing is quite appropriate to refresh old bleeding region and bleeding region in shadow. A novel total variation model (TV-Retinex) is proposed to solve the Retinex problem quickly;...

In 1964 Edwin H. Land formulated the Retinex theory, the first attempt to simulate and explain how the human visual system perceives color. Unfortunately, the Retinex Land-McCann original algorithm is both complex and not fully specified. Indeed, this algorithm computes at each pixel an average of a very large set of paths on the image. For this reason, Retinex has received several interpretati...

Tone reproduction is now widely used in the field of HDR imaging and image enhancement, especially to provide the proper luminance, so that captured images give the same sensation as the real scene. As a result, a high contrast and naturalness of colors can be obtained. In recent studies on tone reproduction with the objective of reproducing natural looking colors in digital images, an integrat...

An experimental analysis of chromatic equalization based on a new implementation of the Retinex algorithm is presented. The experiments are carried out on a colored Mondrian patchwork illuminated with different commercial light sources and on synthetic images generated with a photometric ray tracer using different illuminants. Regarding the Mondrian patchwork, the spectral characteristics of th...

The last version of Edwin Land's retinex model for human vision's lightness and color constancy has been implemented. Previous research has established the mathematical foundations of Land's retinex but has not examined speciic design issues and their eeects on the properties of the retinex operation. We have sought to deene a practical implementation of the retinex without particular concern f...

Purpose – Shadows, the common phenomena in most outdoor scenes, bring many problems in practical image processing. Shadow detection and removal, especial in uncalibrated outdoor image, is still a difficult problem. The purpose of this paper is to detect and to remove shadows in single outdoor image based on retinex theory. Design/methodology/approach – The shadow extraction algorithm originates...

Recorded color images differ from direct human viewing by the lack of dynamic range compression and color constancy. Research is summarized which develops the center/surround retinex concept originated by Edwin Land through a singlescale design to a multi-scale design with color restoration (MSRCR). The MSRCR synthesizes dynamic range compression, color constancy, and color rendition and, there...

This paper describes a method that tries to improve the accuracy of a machine vision algorithm for frayed edge detection in coldrolled electrical grain oriented steel plate with usage of the Singular Value Decomposition. The algorithm being improved is based on preprocessing the image with the Multi Scale Retinex algorithm, application of the Sobel filter and additional evaluation logic.

The effort to make efficient Retinex engines motivated the research reported in this paper. In most Retinex-type algorithms the computational engine is some (possibly nonlinear) variant of a large support low-pass filter. The presented work relies on the fact that recursive (2D IIR) filtering is an efficient method to implement such large support linear space invariant filters. We propose a gen...