Extraction of color-intensity feature towards image authentication

• Published in: Journal of Shanghai University Vol. 14; no. 5; pp. 337 - 342
• Main Author: 刘婷婷 王朔中 张新鹏 郁志鸣
• Format: Journal Article
• Language: English
• Published: Heidelberg Shanghai University Press 01.10.2010; School of Communication and Information Engineering, Shanghai University, Shanghai 200072, P. R. China
• Subjects: Classical Mechanics; Engineering; Environment; Life Sciences; Materials Science; Mathematical and Computational Engineering; Mechatronics; YCbCr; 图像映射; 平均强度; 提取方法; 特征向量; 相似性度量; 颜色强度; image hash; tamper detection; feature extraction; color space; authentication
• ISSN: 1007-6417; 1863-236X
• DOI: 10.1007/s11741-010-0655-2

A color-intensity feature extraction method is proposed aimed at supplementing conventional image hashing algorithms that only consider intensity of the image. An image is mapped to a set of blocks represented by their dominant colors and average intensities. The dominant color is defined by hue and saturation with the hue value adjusted to make the principal colors more uniformly distributed. The average intensity is extracted from the Y component in the YCbCr space. By quantizing the color and intensity components, a feature vector is formed in a cylindrical coordinate system for each image block, which may be used to generate an intermediate hash. Euclidean distance is modified and a similarity metric introduced to measure the degree of similarity between images in terms of the color-intensity features. This is used to validate effectiveness of the proposed feature vector. Experiments show that the color-intensity feature is robust to normal image processing while sensitive to malicious alteration, in particular, color modification.