Abstract: In camouflage design, extracting the dominant color from target background is an important step. A drawback of common color clustering methods is the requirement of supervision. This paper proposes an unsupervised color clustering algorithm based on the chromaticity histogram. The chromaticity histogram is established according to the CIE 1931 system. The cluster center is automatically generated based on the distribution of pixels in the coordinate system. Euclidean distances in the chroma space are calculated one by one between pixels and each cluster center. These pixels are clustered around the
nearest clustering center. Experimental results show that the proposed clustering algorithm can accurately extract the dominant color, and automatically segment the color image. In addition, the algorithm uses less time in image segmentation than common algorithms.

Key words: camouflage design, color clustering, CIE 1931, chromaticity histogram