The discrete image transforms are used for energy compaction primarily and so used in image data compression. The level of energy in the image depends on level of colors used. In this paper we use two discrete image transforms namely Discrete Hadamard Transform (DHT) and Discrete Wavelet Transform (DWT). These transforms are applied on two different color models namely HSV and YCbCr separately ...

We present a color image encryption algorithm by using chaotic mapping and Hartley transform. The three components of color image are scrambled by Baker mapping. The coordinates composed of the scrambled monochrome components are converted from Cartesian coordinates to spherical coordinates. The data of azimuth angle is normalized and regarded as the key. The data of radii and zenith angle are ...

In this paper, a fragile watermarking technique using Legendre transform (LT) has been proposed for color image authentication (LTCIA). An initial pixel adjustment is used to ensure that it never exceeds the range of a valid pixel component. The Legendre transform (LT) is applied on each pair of pixel components of the carrier image in row major order. The transformed components of each transfo...

Reversible color component transforms derived by the LU factorization are briefly described. It is possible to obtain an reversible implementation to a given component transform, even if the original transform is irreversible. Some examples are presented and their performances are compared in image compression. key words: component transform, reversible transform, image compression, LU factoriz...

In this article, a new color feature extraction algorithm and a new hybrid color space is proposed in order to further enhance the color face recognition performance. First, it is searched the best combination way of color component images of the YIQ, the YCbCr, and the HSV color spaces transformed from RGB color space. Secondly it is decomposed by applying curvelet transform to each of color c...

In this paper, a new fast method for detecting human faces in color images using wavelet transform is proposed. The face detection algorithm has three stages, where chrominance, shape and frequency information are used respectively. The algorithm starts at the lower resolution version of the image obtained from the wavelet transform, so that the amount of data to be processed is greatly reduced...

We present a linear algorithm for the computation of the illuminant change occurring between two color pictures of a scene. We model the light variations with the von Kries diagonal transform and we estimate it by minimizing a dissimilarity measure between the piecewise inversions of the cumulative color histograms of the considered images. We also propose a method for illuminant invariant imag...

Simple and fast methods for transforming color photographs into non-photorealistic images such as stained-glass and color-sketch images. We propose two types of methods decomposing images into homogeneous color regions. One type is an edge-based method and the other is a region-based approach. In the edge-based methods, an input image is tessellated into Apollonius cells by using the distance t...

This paper presents a novel color face recognition algorithm by means of fusing color and local information. The proposed algorithm fuses the multiple features derived from different color spaces. Multiorientation and multiscale information relating to the color face features are extracted by applying Steerable Pyramid Transform (SPT) to the local face regions. In this paper, the new three hybr...

There is significant difference in the imaging features of infrared image and color image, but their fusion images also have very good complementary information. In this paper, based on the characteristics of infrared image and color image, first of all, wavelet transform is applied to the luminance component of the infrared image and color image. In multi resolution the relevant regional varia...