According to the high complexity of extracting feature of radar signal using image processing method, a new method for extracting feature was proposed. Firstly, the time-frequency distribution was gained based on the adaptive Gaussian kernel time frequency analysis, then through analyzing the physical meaning of each element, one dimension vector could be found through a simple arithmetic instead of the complicated method through processing the time-frequency figure with image processing means, so the real-time requirement for sorting radar signal could be satisfied. The simulation results verify the efficiency of the proposed algorithm. Additionally, the accuracy can be kept at a high level while the Signal-to-Noise Ratio (SNR) is low.

To better evaluate image quality, the authors proposed a top-down no-reference image objective quality evaluation method based on the research of human visual model and human visual characteristics. The new method divided the target image into segments and calculated every segment in different color channel, then output the average visual property values. It made evaluation model not only be consistent with the advantage of objective quality assessment, but also took into account the human visual experience. It was consistent with the objectivity and subjectivity of human eyes. The validated results of image subjective evaluation on database of TEXAS University of United States prove that the proposed method gets better consistency with subjective assessment.