SAR single-shot image internal brightness compensation method based on gamma correction

Abstract

The invention belongs to the technical field of the digital image processing, and specifically relates to a SAR single-shot image internal brightness compensation method based on gamma correction. Thecompensation method specifically comprises the following steps: S1, finding a pixel point gray maximum value by traversing an image; S2, acquiring a normalized image; S3, performing gamma correction;S4, performing a difference image, performing the difference image on the normalized image and the corrected image; S5, adjusting the gray level, and multiplying the difference image with the pixel point gray maximum value to obtain the gray-level range of the difference image as [0-255], adjusting a result image of the gray-level, namely the final result image of the algorithm processing; and S6, outputting image: outputting the image after processing in S5. The SAR single-shot image internal brightness compensation method based on gamma correction disclosed by the invention has the featureof realizing the precise compensation of the image brightness, the color uniformity and the preserving information are better.

Description

technical field [0001] The invention belongs to the technical field of image processing, and in particular relates to a method for compensating internal brightness of a SAR single scene image based on gamma correction. Background technique [0002] Gaofen-3 satellite is a remote sensing satellite of China Gaofen Special Project, and it is the synthetic aperture radar (SAR) satellite with the most imaging modes in the world. The satellite imaging has a wide width, combined with the advantages of high spatial resolution, it can not only realize a large-scale general survey, but also a detailed survey of a specific area, which can meet the needs of different users for different target imaging. [0003] However, due to changes in SAR imaging angles, terrain, radar antenna patterns, and strong backscattering of special ground objects, there is a problem of uneven brightness distribution inside a single SAR image, showing obvious bright spots, which seriously affects subsequent im...

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Problems solved by technology

[0011] The frequency-domain low-pass filtering algorithm can reduce the bright channel of the image to a certain extent, but it does not effectively eliminate the bright channel phenomenon. As a result, the gray level of the image still shows obvious differences; Larger, multiplied to obtain the low-pass filtered spectrogram and inverse fast Fourier transform to obtain the background image pixel value is greater than the original image pixel value, then the corresponding pixel gray value of the difference

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