A Study Of SAR Image Quality Evaluation

SAR plays an important role in military reconnaissance and civil activity. With the development of SAR technology, SAR images come into widely used. However, there are some issues in SAR images because of the nature of SAR images. And these problems have a serious impact on SAR image’s application. So, it is essential and significant to study SAR image quality evaluation.This paper introduces the features of SAR imaging, and the SAR image characteristics, including the standpoint of the geometric, radiation feature, statistical distribution. Then traditional SAR image quality evaluation is studied in detail. Fro m the perspective of SAR image acquisition, six objective parameters are selected to evaluate SAR image quality, including mean, variance, equivalent number of looks, radiometric resolution, grayscale resolution and entropy. SAR image quality evaluation based on the connectivity of edge is studied in this paper. Firstly, the contributions of edge pixels to the connectivity of edge segments are measured by distances and the edge scale. The weighting mean value of these connectivity indexes is taken as the connectivity evaluation index of an edge image. The result shows that this method can evaluate objectively the connectivity of an image.The advantages and disadvantages of the Gray- level Co-occurrence Matrix and semivariogram in SAR image processing are studied in this paper. And semivariogram is used to fulfill SAR image quality evaluation based on texture features. Due to the comparability of the human visual system with discrete wavelet transform, an new SAR image quality evaluation method is proposed in this paper. The effectiveness of the approach is validated by the computer simulation using the real SAR images.