The image database of crime scene investigation (CSI)has the characteristics of high confidentiality

rare image content and so on.Aiming at the complexity of the content and the ambiguity of the target object

the DCT-DCT wave texture feature is proposed

which is fused with HSV color histogram feature and GIST feature to form the fusion feature.Compared with the commonly used image features

DCT-DCT wave texture feature can get higher retrieval efficiency

and the average retrieval precision rate of the fused features is higher than that of the three features.Finally

the semantic analysis technology is introduced into the retrieval process

and an image retrieval algorithm based on the optimization of retrieval results is proposed.Support vector machine (SVM)classifier was used to extract the semantic of the query image.The semantic analysis of the results of the first retrieval is carried out

and the second retrieval scheme is selected according to the proportion of semantic categories in the initial retrieval results.The algorithm can further improve the average retrieval accuracy based on case-by-case query.