Research of Frequency Band Derangement of Wavelet Packet and Application

The reason of frequency band derangement and the rule of frequency band division of wavelet packet transform were analyzed. The correct frequency band sequence of wavelet packet transform (WPT) was found. Then in this study, because of the texture feature information is on the middle frequency band, according to the conclusion, we select the correct frequency band sequence of WPT to classify tea categories, the images of tea were captured by multi-spectral imager (3CCD). Firstly, image was transformed by WPT, the decomposed lever was 3, so 8 nodes were obtained, and the 8 nodes were rearranged. The node (2,3) and node (2,7) were selected as the input texture feature set of training and prediction using by least squares-support vector machine (LS-SVM). The nodes which were selected by the correct frequency band is satisfactory as evident from the experiments; up to 100% accuracy is obtained using LS-SVM