Firstly, the shadows in SAR images have an inverse relationship with the signal of the aircraft body in optical images in terms of grayscale. Therefore, it is possible to simply invert the grayscale of one of them. In this study, SAR images were chosen for grayscale inversion. After a simple grayscale inversion, the network detected a significant number of aircraft in the image at a confidence level of 0.2, while only part of aircraft were detected in the image without inversion. Besides, a series of adjustments were made to the brightness and contrast of the grayscale inverted image in order to find the optimal setting for aircraft detection. After scanning and adjusting the brightness and contrast, the network detects a certain number of additional aircraft in the grayscale inverted images at a confidence level of 0.2. The maximum number of aircraft detections was achieved at a specific filtering spatial frequency after applying filtering with different spatial frequencies. The overall detection result achieved an accuracy of over 80%.The maximum number of aircraft detections was achieved at a specific filtering spatial frequency after applying filtering with different spatial frequencies. The overall detection result achieved an accuracy of over 80%. |
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Synthetic aperture radar
Object detection
Target detection
Image processing