Enhanced wavelet correlogram methods for image indexing and retrieval

In this paper, three new algorithms including optimal quantized wavelet correlogram (OQWC), wavelet CCV-correlogram (W3C), and color-W3C (CW3C) for content-based image indexing and retrieval are presented. In OQWC the threshold levels for wavelet coefficient quantization are optimized using an evolutionary process. W3C is an extension of OQWC that utilizes color coherence vectors (CCV) to include gray level and texture information in image index. Finally, CW3C is an extended version of W3C for effective color image indexing. The retrieval results obtained by the new methods on a 1000 image database demonstrate significant improvements in recall and rank compared to wavelet correlogram and SIMPLIcity methods.