Antistretch Edge Detector for SAR Images

Abstract

In this letter, an antistretch edge detector has been proposed for synthetic aperture radar (SAR) images. Traditional detectors using anisotropy edge detection filters often incur severe edge stretch. If isotropy edge detection filters are used, the detectors usually have poor edge resolution. Hence, we skillfully fuse an anisotropy edge detection filter with an isotropy one. By embedding the fused filter into the routine ratio-based SAR edge detector, an antistretch edge detector is proposed. Benefiting from the fused edge detection filter, the proposed edge detector can obtain a good antistretch ability and keep a high edge resolution. A theoretical analysis indicates that the computational complexity of the proposed edge detector is close to conventional ratio-based edge detectors. The fusion operation will not affect the constant false alarm rate property. The receiver-operating-characteristic curves are used to objectively evaluate the proposed detector. Experimental studies show that the proposed detector has a lower false positive rate than the majority of detectors using only anisotropy filters or isotropy filters. Furthermore, the experimental results on simulated and real-world SAR images show that the proposed antistretch edge detector can obtain an accurate edge map.