Image encoding method, device using the same, and computer program

Abstract

When entropy-encoding a converted quantized amount obtained by converting an image into a frequency region and quantizing it, if the output code bit quantity of the entropy encoding exceeds a predetermined amount, an image obtained by rebuilding the converted quantized value is outputted from an image encoding device. This guarantees an encoding delay caused by re-encoding to be a constant time without increasing the circuit size of the encoding device and provides an image encoding device of a subjectively high quality.

Description

Image encoding method, device and computer program using the method technical field The present invention relates to an image coding technique based on variable length coding or arithmetic coding isentropic coding. In particular, it is preferably used in an image coding device. Background technique Conventionally, an image encoding device digitizes a moving image input from the outside, and then performs encoding processing according to a predetermined image encoding method to generate a bitstream (bitstream) which is encoded data. As the above-mentioned image coding method, there is ISO / IEC14496-10Advance VideoCoding (non-patent document 1ISO / IEC14496-10AdvanceVideoCoding), which has been standardized in recent years. device). Referring to FIG. 1, the structure and operation of a conventional image coding apparatus that takes digitized image frames as input and outputs a bit stream will be described. Referring to FIG. 1 , a conventional image encoding device is comp...

AI Technical Summary

Problems solved by technology

When the pipeline in Figure 7 is blocked frequently, the time delay (hereinafter referred to as encoding delay) to end the encoding of the entire image frame cannot be ignored.

Therefore, in the case of simply pipelining the existing encoding device, it is impossible to ensure that the encoding of the image frame is completed in real time.

Needless to say, the above-mentioned encoding delay can be avoided if a plurality of MB encoding devices 2000 are provided, but there is another problem that the circuit scale of the encoding device increases.

In addition, in the above-mentioned original image PCM re-encoding, since the frequency characteristic of the MB reconstructed from the original image by the original-image PCM re-encoding is different from that of the surrounding MB reconstructed from the decoded image, there is also a subjective inconsistency in image quality. question on

This problem is unavoidable with only a plurality of MB encoding devices 2000

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