JPEG compliant encoder utilizing perceptually based quantization

Robert J. Safranek

doi:10.1117/12.172663

1 May 1994 JPEG compliant encoder utilizing perceptually based quantization

Robert J. Safranek

Proceedings Volume 2179, Human Vision, Visual Processing, and Digital Display V; (1994) https://doi.org/10.1117/12.172663
Event: IS&T/SPIE 1994 International Symposium on Electronic Imaging: Science and Technology, 1994, San Jose, CA, United States

Abstract

The international JPEG (Joint Photographics Experts Group) standards for image compression deal with the compression of still images. It specifies the information contained in the compressed bit stream, and a decoder architecture that can reconstruct an image from the data in the bit stream. However, the exact implementation of the encoder is not standardized. The only requirement on the encoder is that it generate a compliant bit stream. This provides an opportunity to introduce new research results. The challenge in improving these standards based codecs is to generate a compliant bitstream that produces a perceptually equivalent image as the baseline system that has a higher compression ratio. This results in a lower encoded bit rate without perceptual loss in quality. The proposed encoder uses the perceptual model developed by Johnston and Safranek to determine, based on the input data, which coefficients are perceptually irrelevant. This information is used to remove (zero out) some coefficients before they are input to the quantizer block. This results in a larger percentage of zero codewords at the output of the quantizer which reduces the entropy of the resulting codewords.

Citation Download Citation

Robert J. Safranek "JPEG compliant encoder utilizing perceptually based quantization", Proc. SPIE 2179, Human Vision, Visual Processing, and Digital Display V, (1 May 1994); https://doi.org/10.1117/12.172663

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available