The Transactions of the Korea Information Processing Society (한국정보처리학회논문지)
- Volume 6 Issue 11
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- Pages.3150-3156
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- 1999
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- 1226-9190(pISSN)
JPEG Image Quantization Method with Variable Thresholds
가변 임계값을 갖는 JPEG 영상의 양자화 방법
- O, Ha-Ryeong ;
- Yun, Seok-Hyeon ;
- Seong, Yeong-Rak (Dept. of Electronic Eng., Kookmin University)
- Published : 1999.11.01
Abstract
In this paper, VTQM(Variable Threshold Quantization Method) is proposed, which enhances PSNR by composing the advantages of round-off and truncation quantization methods. From vast experiments, PSNR's of JPEG images with the method are compared with that of standard JPEG methods. At the boundary which affects the compression ratio, VTQM quantizes with a new threshold to reduce the length of compressed data; otherwise, VTQM employs the round-off quantization method to preserve the original image information. As a result, VTQM reduces bit rate while preserving the image quanity. The experimental results show that VTQM enhances PSNR by 0.2-0.3dB., 0.4-0.5dB, with the same bit rate than those of the traditional truncation and round-off quantization methods, respectively.
Keywords