Remote-sensing image compression method for discrete wavelet transform based on self-adaptation direction prediction

Abstract

The invention discloses a remote-sensing image compression method for discrete wavelet transform based on self-adaptation direction prediction and belongs to the technical field of remote-sensing image processing. The method comprises the steps that 1) 15 directions which are formed by close-end integer and fraction pixels and far-end integer pixels are considered in a combined mode, a direction graph is established; 2) remote-sensing images are subjected to two-dimensional discrete wavelet transform based on self-adaptation direction prediction, namely quadtree division based on direction consistency is used for dividing the remote-sensing images to a plurality of image blocks which are not overlapped, a new direction prediction model is used for obtaining the best transformation direction of each image block, lifting wavelet transform is completed in the direction; 3) a transformed image coefficient is subjected to SPIHT coding, direction information is subjected to self-adaptation arithmetic coding, and a final code stream is obtained. According to the method, visual quality and peak signal-to-noise ratio of the remote-sensing images are effectively improved, computing complexity of direction wavelet transform is lowered, and the method can be widely used for efficient coding compression of the aviation and satellite remote-sensing images.

Description

technical field [0001] The invention belongs to the technical field of remote sensing image compression, and relates to a remote sensing image compression method based on adaptive direction prediction discrete wavelet transform. Background technique [0002] In recent years, with the rapid development of earth observation technology, the spatial resolution of remote sensing images has been significantly improved, and the amount of remote sensing data has also increased geometrically, which has brought great challenges to data storage and transmission. In the compression technology, the existing technology for natural scene image compression is often used, but the compression effect is very limited. These technologies do not take into account the large amount of high-spatial resolution remote sensing image data, rich texture and edge information, and clear object structure. features. Therefore, it has become a key technology in the development of remote sensing to study the ...

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Problems solved by technology

[0007] In order to overcome the shortcomings of the traditional lifting wavelet that cannot effectively use the direction information of remote sensing images, and the traditional direction wavelet transform has high computational complexity and insufficient number of directions, the present invention constructs a direction discrete wavelet that can make full use of the characteristics of remote sensing images and can be quickly realized transform, which can effectively concentrate the energy of various edges or texture directions in the image, relying on the new directional discrete wavelet transform designed in the present invention, a fast and efficient remote sensing image compression method is realized, thereby significantly improving the remote sensing image The compression efficiency of the reconstructed image is significantly improved in both subjective quality and objective evaluation.

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