Brightness Compensation Method of SAR Single Scene Image Based on Local Histogram Compression

Abstract

The invention relates to a SAR single scene image brightness compensation method based on local histogram compression, which includes the following steps: S1. For the SAR single scene image to be processed, select an area with uneven brightness as a selected area; S2. Traverse the selected area area, and obtain the lowest pixel gray value and the highest pixel gray value in the selected area; S3. Make a histogram of the selected area, and select the compression probability p of the histogram to obtain the selected area. The maximum grayscale value x after compression, the grayscale range of the selected area is divided into two parts [A,x] and [x+1,B]; S4. Obtain the appropriate compression factor m through the iterative method f , so that the gray level of the selected area is compressed from the initial range [A, B] to [A, x]; S5. Traverse the selected area, for any pixel gray value I k , if I k ∈[A,x], then output I k ; Otherwise, output the image after brightness compensation. The invention can effectively avoid the black spot phenomenon, retain the detailed information of the image, and obtain satisfactory brightness compensation effect.

Description

technical field [0001] The invention belongs to the technical field of SAR image brightness compensation in the field of image processing, in particular to a SAR single-scene image brightness compensation method based on local histogram compression. Background technique [0002] The unique coherent imaging method of Synthetic Aperture Radar (SAR) enables it to penetrate clouds, rain and snow, and produce image products with higher resolution and contrast, so it is widely used in agriculture, disaster monitoring, geology, lakes, ocean monitoring and navigation, etc. field. The wide application and in-depth research of SAR images often require images with balanced brightness, moderate contrast, and consistent colors, so that SAR images can be used to make various DOM mosaic products and integrate them with geographic information systems. However, SAR is a microwave slant-range imaging radar. The brightness information of SAR images actually reflects the backscattering intensi...

AI Technical Summary

Problems solved by technology

[0004] There are some problems in the above brightness compensation methods: the frequency domain low-pass filtering method cannot guarantee that the pixel gray value of the background image does not exceed the original image, if some pixel values ​​of the background image are greater than the original image, the corresponding pixel gray value of the difference image Negative values ​​will appear in the brightness value, which will lose the corresponding detail information, and show black spots on the brightness compensation image

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