A new wavelet image compression algorithm was proposed based on morphological dilation and the positional information of the important coefficient couplet belt.

After the DWT of the original image data, and according the similarity between the band shown by subband coefficients in the space and the direction, the collection of pixels is redefined as set tree.

Furthermore, an effective experimental scheme based on the TDFWM IL structure of LED is proposed for the observation of inter and intra band carrier relaxation rates in the active medium.