KR970073158A - IMPROVED IMAGE CODING SYSTEM HAVING FUNCTIONS FOR CONTROLLING GENERATED AMOUNT OF CODED BIT STREEM - Google Patents

Abstract

The present invention calculates the complexity of an image to be currently coded based on a quantization error value between a current frame input for coding and a previous frame reconstructed in an encoding system including MC-DCT and quantization, To a video encoding system having a bit amount adjustment function capable of adaptively adjusting a bit generation amount after encoding by selectively removing a high frequency component of an input video signal using a one-dimensional low-pass filter according to the present invention. According to an aspect of the present invention, a quantization error value is calculated for each frame based on a pixel value difference signal between a current frame and a reconstructed previous frame, and averaged quantization error values of the calculated frame are used to calculate an average quantization error value Quantization error calculation means for calculating a quantization error; The average error value of the calculated plurality of frames is referred to as the complexity of the frame to be currently encoded through the encoding means and the frequency pass bandwidth of the current frame inputted for encoding is limited based on the flatune error value of each detected frame A control means for generating a filter control signal for the filter; And by applying one-dimensional low-pass filtering to an input current frame to provide an input current frame as a current frame signal for motion estimation and compensation based on the generated filter control signal, Dimensional low-pass filtering means for providing the frame signal from which the frame signal has been removed to the encoding means with the current frame signal for motion estimation and compensation, so that the amount of bits generated after encoding without increasing the step size excessively during quantization in the sub- Can be effectively controlled.

Description

IMPROVED IMAGE CODING SYSTEM HAVING FUNCTIONS FOR CONTROLLING GENERATED AMOUNT OF CODED BIT STREEM

Since this is a trivial issue, I did not include the contents of the text.

FIG. 1 is a block diagram of an image encoding system having a bit generation amount control function according to a preferred embodiment of the present invention. FIG. 2 is an example of an 8 × 8 pixel block according to the present invention. FIG. 6 shows an example of a one-dimensional low-pass filter coefficient of order 7 as an example.

Claims (5)

And an error signal between predictive frames obtained through motion estimation and compensation of a current macroblock unit using the present frame and a reconstructed previous frame, through encoding means including discrete cosine transform, quantization, and entropy encoding, And a quantization step of generating a quantized bit stream, wherein the quantization step has a function of adjusting a bit generation amount, the step size of which is reduced based on the fullness state information of the bit stream stored in an output side buffer, A quantization error calculation unit for calculating a quantization error value for each frame based on the pixel value difference signal between the reconstructed previous frames and averaging the quantization error values of the calculated frame to calculate an average quantization error value for a plurality of predetermined frames Way; The average error value of the calculated plurality of frames is referred to as the complexity of a current frame to be encoded through the encoding means and a frequency error of the current frame inputted for encoding based on the average error value of each detected frame Control means for generating a filter control signal for limiting bandwidth; And providing the input current frame to the encoding means as a current frame signal for motion estimation and compensation based on the generated filter control signal or applying one-dimensional low-pass filtering to the input current frame, Further comprising a one-dimensional low-pass filtering means for providing a frame signal from which a high-frequency component has been removed to the coding means as a current frame signal for the motion estimation and compensation, . 2. The apparatus of claim 1, wherein the filter control signal includes an average quantization error value of each of the calculated frames, an average error value of a plurality of transmitted frames per second obtained by averaging the average quantization error values of the respective frames, Wherein the bit error rate is determined according to the standard deviation of the value. 3. The image encoding system according to claim 2, wherein the filter control signal is a logic signal of a high or low level. 2. The image encoding system of claim 1, wherein the one-dimensional low-pass filtering for the current frame is performed in 8x8 block units. The method of claim 1 or 4, wherein the one-dimensional low-pass filtering of the 8x8 block is performed in a horizontal-vertical or vertical-horizontal direction of each pixel position in the 8x8 block Image coding system with bit - issue adjustment function. ※ Note: It is disclosed by the contents of the first application.