Synthetic aperture radar (SAR) image compression method based on target area extraction and direction wave

Abstract

The invention discloses a synthetic aperture radar (SAR) image compression method based on target area extraction and direction wave, and mainly solves the problems of less edge information stream distribution and loss of important information due to the fact that the same transform compression strategy is used in an image target area and a background area in the existing method. The method comprises the implementation steps of extracting a texture map of an SAR image by a variation coefficient; carrying out quadtree partitioning on the SAR image, dividing an image block into the target area and the background area by the texture map; detecting a diverting pair of the target area by the texture map, and carrying out pruning processing on partitioned images; and carrying out directionlets transformation on the target area, carrying out wavelet transformation on the background area, and respectively encoding the coefficients of the target area and the background area by a set partitioning in hierarchical trees (SPIHT) encoding method. The SAR image compression method has the advantage of well protecting the information of the target area by different transform compression strategies in the target area and the background area, and can be applied to real-time transmission and storage of the SAR image.

Description

technical field [0001] The invention belongs to the technical field of image compression, relates to the compression of SAR images, and can be used for real-time transmission and storage of SAR images. Background technique [0002] Synthetic Aperture Radar (SAR) technology plays a vital role in national economy, geological exploration and military affairs, and SAR image processing is an important part of SAR technology. Because SAR images have massive data, it puts a lot of pressure on data storage and transmission, so effective compression of SAR images is an urgent need in SAR image applications. SAR uses the backscattering of electromagnetic waves on the surface of the object to image. Due to this imaging mechanism, the image will be affected by coherent speckle noise. The correlation between the pixels of the image is low, and the image entropy value is large, which affects the SAR image compression. Key factor. [0003] JPEG technology will produce obvious "mosaic" bl...

AI Technical Summary

Problems solved by technology

However, due to the different areas of the scene in the SAR image, the edge information contained in the image and its importance are very different. Using the same transformation compression strategy for different areas of the SAR image in the compression will lead to the distribution of these edge information in the compression. The code stream is relatively small, which causes important information to be lost without protection, resulting in a reduction in image compression quality

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