Image Retrieval Based on NSCT and Krawtchouk Moments

To further improve the accuracy of image retrieval,an algorithm based on nonsubsampled contourlet transform(NSCT) and Krawtchouk moments is proposed.Firstly,the image is decomposed to the low resolution image with NSCT,extracting the contourlet coefficients of each decomposition level of different direction and using the statistical features of the coefficients as texture features of the image.Then,the Krawtchouk moments are employed to extract shape features of the image.Finally,the image retrieval is achieved based on weight distance measure.A comparison is made with the method of using NSCT and Zernike features.Experimental results show that the extracted features have the properties of translation,rotation and scaling invariance,and the proposed algorithm can acquire the higher retrieval accuracy.