Applications of Curvelet Transform in Low Contrast Target Recognition

The target in low contrast image cannot be discriminated from cluttered scene by using joint transform correlator as its indistinct edge.Aimed at this problem,an image enhancement based on Curvelet transform was adopted to process the target's joint image.In the wavelet analysis,the Curvelet transform is a better multi-resolution tool to analyze and understand the image feature.Both gray contrast and edge can be enhanced by adjusting the high and low frequency coefficients of Curvelet transform with different methods.As an example,a tank's image with low contrast was processed by using Curvelet transform.The gray contrast of original image was increased from 4.16% to 29.37%.The computer simulation and optical experiment results show that a bright pair of correlation peaks are obtained after enhancing the image,and the recognition for the target in low contrast image is realized successfully.