Unlock instant, AI-driven research and patent intelligence for your innovation.

Automatic bit-rate control method and image compression apparatus

A bit-rate-controlled, automatic technology used in image communications, digital video signal modification, electrical components, etc.

Active Publication Date: 2006-10-25
VIMICRO ELECTRONICS CORP
View PDF0 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0015] The technical problem solved by the present invention is to provide an automatic bit rate control method and an image compression device, so as to correctly predict the next frame during the image compression process when a large change in the Q value between two frames of images is detected. The Q value of the image eliminates the situation of frame loss caused by excessive image compression or insufficient compression, so as to ensure high-quality image compression

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Automatic bit-rate control method and image compression apparatus
  • Automatic bit-rate control method and image compression apparatus
  • Automatic bit-rate control method and image compression apparatus

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0040] Such as Figure 5 As shown, it is a schematic diagram of the principle of the image compression device according to the embodiment of the present invention. Compared with the existing compression device, this embodiment adds: forced bit rate control (RBRC) module 501, Q value compensation (Q- complement) module 502, and a Q value correction (Q-correction) module 503. Each of the modules is configured with a number of registers, storing parameters required by each.

[0041] Among them, the Q value correction module 503 is used to store the difference threshold between the preset current Q value and the next Q value, and judge the difference between the current Q value and the predicted next Q value during the image compression process. Whether the value exceeds the preset threshold, if it exceeds the preset threshold, the next Q value will be adjusted to further increase the difference between the current Q value and the next Q value, and the adjusted next Q value will ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention includes procedures: setting up threshold of difference value between current Q value and next time Q value; in procedure of image compression, detecting difference value between Q value utilized by current compression and next time Q value calculated in real time; when the said difference value exceeds threshold of difference value ser up, the method increases difference value, and uses adjusted Q value to compress next frame image; further, resetting condition for detecting compression ratio; when current frame of image is compressed to proportion accorded with detection condition, predicting whether the completed compressed entire image causes overflow of storage space based on current Q value used; if yes, then discarding coefficient of alternating current obtained through discrete cosine transform, and compensating current Q value. The invention better controls image compression distortion in JPEG coding as well as image frame loss caused by not enough compression.

Description

technical field [0001] The invention relates to an automatic bit rate control method and an image compression device, in particular to an automatic bit rate control method for JPEG encoding and an image compression device. Background technique [0002] When designing the hardware circuit of the video chip, it is considered that the size of the storage space after image JPEG compression is fixed, and the smaller the image compression rate, the smaller the image distortion. Therefore, a fixed image compression rate is selected to maintain the maximum utilization of the storage space. is very necessary. [0003] In the JPEG coder, the image compression rate is adjusted through the Q value, and the automatic bit rate control is accomplished through an adaptive Q value adjuster. The purpose of the Q value adjustment is to predict the Q value of the next frame image, so that the compression rate of the next frame image can meet expectations. [0004] The principle of JPEG compre...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): H04N19/146H04N19/61
Inventor 郦文其汪源居晓波
Owner VIMICRO ELECTRONICS CORP