Low Bit Rate Image Coding Method Based on Block Adaptive Sampling and Super-resolution Reconstruction

Abstract

The invention discloses a low bit rate image coding method based on block self-adaptive sampling and super-resolution reconstruction. The low bit rate image coding method comprises the steps of dividing an image into blocks, and performing multi-mode downsampling of the image blocks; performing JPEG encoding in multiple quantifying modes for the sampled image blocks; reconstructing the JPEG decoded image blocks by using a super-resolution method based on sparse representation; selecting sampling and quantifying modes of each image block through rate-distortion optimization; performing sampling, JPEG encoding and super-resolution reconstruction of the image blocks according to the selected modes; and combining the decoded image blocks into an image. The invention can significantly improve the rate-distortion performance of JPEG in low and medium code rate segments, and can ensure that the performance of a high code rate segment is comparable to the JPEG standard. Moreover, at the same code rate, the decoded image by the method in the invention has better visual effects than the JPEG does, especially at the low code rate segment. The invention can be applied to image compression in the bandwidth-limited fields of networks, wireless communication and the like.

Description

technical field [0001] The invention relates to image compression and image super-resolution reconstruction technology, in particular to a low-bit-rate image coding method based on block adaptive sampling and super-resolution reconstruction, and belongs to the field of image communication. Background technique [0002] The purpose of image compression is to reduce the redundancy between image data, reduce the amount of data, and store and compress more efficiently. As one of the basic technologies in the image field, image compression has always been concerned by researchers. With the popularization of high-resolution images and videos, image compression technology becomes more important. Currently, JPEG is the most widely used still image compression standard in the fields of network and wireless communication. However, the compression performance of JPEG is poor in the low bit rate segment, and there are serious compression artifacts in decoded images, such as blocking e...

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Problems solved by technology

However, this method is only applicable to a very low bit rate, that is, the compression performance of JPEG can be improved in the low bit rate segment, while the compression performance of the medium and high bit rate segment will decrease, and the bit rate range for performance improvement varies from graph to graph, so There are certain limitations in practical use

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