Method and apparatus for region-based moving image encoding and decoding

Abstract

In partitioning and encoding an image into multiple regions, the degree of freedom of the region shape has generally been low and setting regions based on image features was difficult. A moving image encoding apparatus includes a region partitioning section, an encoder, and a memory for motion-compensated prediction. The region partitioning section includes a partitioning processing section and an integration processing section. The partitioning processing section partitions the input image based on a criterion relating to the state of partition. The integration processing section integrates mutually close regions based on a criterion relating to the state of integration. Thereafter, each region is encoded. A large variety of region shapes can be produced by the integration processing section.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] This invention relates to a method and apparatus for inputting and encoding a moving image and to an apparatus for decoding the encoded moving image. This invention particularly relates to a technique for encoding an image frame by first partitioning it into multiple regions and to a technique for decoding the encoded image frame. [0003] 2. Description of the Related Art [0004]FIG. 1 is a block diagram of a first prior art showing the configuration of a moving image encoder based on ITU-T recommendation H.263, wherein numeral 1 indicates an input digital image signal (hereinafter referred to simply as an input image), numeral 101 indicates a differentiator, numeral 102 indicates a prediction signal, numeral 103 indicates a prediction error signal, numeral 104 indicates an encoder, numeral 105 indicates encoded data, numeral 106 indicates a decoder, numeral 107 indicates a decoded prediction error signal, numeral 108...

AI Technical Summary

Benefits of technology

[0011] The present invention takes into consideration these problems with the object of providing a moving image encoding technique for performing more flexible processing according to the conditions of the image to be processed. The object of this invention, in more concrete terms, is to provide a moving image encoding technique using region partitioning techniques that can accurately handle various image structures. Another object of this invention is to provide a partitioning criterion based on various points of view when partitioning regions for encoding. Still another object of this invention is to provide a technique for correctly decoding the encoded data of regions that have been partitioned into various shapes.

[0012] The moving image encoding method of this invention includes two steps. A first step partitions an input image into multiple regions based on a predetermined partitioning judgment criterion. Until this point, the encoding process is the same as the general conventional region-based encoding. However, in a second step, this invention integrates each of partitioned multiple regions with adjacent regions based on a predetermined integration judgment criterion. Thereafter, in a third step, the image signal is encoded for each of the regions remaining after integration. According to this method, the integration process allows regions to take on various shapes. Thus, a region having a shape closely matching the structure of an image or outline of an object can be generated.

[0013] The moving image encoding apparatus of this invention includes a region partitioning section and an encoder. The region partitioning section includes a partitioning processing section for partitioning the input image into multiple regions based on a predetermined partitioning judgment criterion, and a integration processing section for integrating each of multiple regions partitioned by the partitioning processing section with adjacent regions based on a predetermined integration judgment criterion. The encoder encodes the image signal for each of the regions remaining after integration by the integration processing section. According to this apparatus, a comparatively high image quality can be achieved at comparatively high data compression ratios while flexibly supporting the structures of images.

[0015] The above-mentioned partitioning processing section includes a class identifying section for classifying the importance of regions into classes, and may judge whether or not to partition each region based on an activity to be described later and the class. If the class identifying section references feature parameters in images, the recognition of objects becomes possible thus facilitating more accurate region partitioning.

[0016] On the other hand, the moving image decoding apparatus of this invention inputs and decodes the encoded data of the image that was encoded after being partitioned into multiple regions. This apparatus includes a region shape restoring section and an image data decoder. The region shape restoring section restores, based on region shape information included in the encoded data, the shape of each region that was partitioned during encoding. The image data decoder, after specifying the sequence in which regions were encoded based on the shapes of the restored regions, decodes the image for each region from the encoded data. According to this apparatus, accurate decoding is achieved even if regions having various shapes are generated in the encoding stage.

Problems solved by technology

Therefore, there is naturally a limit in the encoding which can be adapted to the scene structure or features of an image.

However, this apparatus also limits each region to a rectangular shape.

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