Image encoder and image decoder

Abstract

An image coding device comprising: a tile decomposition portion for decomposing image data into tiles each of N pixels x M pixels and outputting the N x M pixels in the tile as an objective data to be coded for a corresponding each of the tiles; an adjacent pixel adding portion for providing a objective tile to be coded with adjacent pixels necessary for wavelet transformation of the objective tile when such pixels exist at the periphery thereof; a wavelet coding portion for extrapolating a predetermined data when no pixel existing at the periphery of the objective tile, decomposing each of the tiles into subbands and outputting only wavelet coefficients of the objective tile; a management information generating portion for generating management information necessary for independently decoding any desirable tile on a subband-by-subband basis; and a coded data integrating portion for attaching the management information to coded information to generate a bit stream, wherein the management information includes information on a location of the coded information for each of the tiles in the bit stream and information for managing and identifying each of the subbands.

Description

technical field [0001] The invention belongs to the technical field of digital image processing, and relates to an image encoding device for efficiently encoding image data and an image decoding device for decoding encoded data encoded by the image encoding device. Background technique [0002] FlashPix Format Specification Version 1.0 has been proposed as an image format for converting natural images into digital data and then processing them with a computer. [0003] In this format, data of a plurality of resolutions are simultaneously held in order to quickly retrieve data of a desired resolution according to the capability of the display / printing device or the user's request. In addition, when enlarging, reducing, or editing an image, since only necessary parts of the image data are processed, the image is divided into rectangular block units and saved in order to reduce the load. [0004] use figure 1 and FIG. 2 illustrates an encoding device for encoding an image acc...

AI Technical Summary

Problems solved by technology

[0034] In other words, unlike the JPEG encoding method such as fast imaging, since the encoding process is limited to the rectangular block, the encoding in units of rectangular blocks is easy. In the case of wavelet transform encoding, since the processing exceeds the range of the rectangular block, there is a problem. Difficulty in encoding processing and management in units of rectangular blocks

[0035] In addition, in the existing wavelet transform coding, it is necessary to be able to save all image 3 The output of the wavelet transform part 31 in Figure 5 The memory of the wavelet transform coefficient in (B), at this time, the wavelet transform coefficient has the same resolution as the original image, so there is a problem of increasing the memory requirement

The problem becomes more pronounced when dealing with high-resolution images

Images