Perceptual coders and perceptual metrics

Junqing Chen; Thrasyvoulos N. Pappas

doi:10.1117/12.429485

8 June 2001 Perceptual coders and perceptual metrics

Proceedings Volume 4299, Human Vision and Electronic Imaging VI; (2001) https://doi.org/10.1117/12.429485
Event: Photonics West 2001 - Electronic Imaging, 2001, San Jose, CA, United States

Abstract

We examine perceptual metrics and use them to evaluate the quality of still image coders. We show that mean-squared- error based metrics fail to predict image quality when one compares artifacts generated by different types of image coders. We consider three different types of coders: JPEG, the Safranek-Johnston perceptual subband coder (PIC), and the Said-Pearlman SPIHT algorithm with perceptually weighted subband quantization, based on the Watson et al. visual thresholds. We show that incorporating perceptual weighting in the SPIHT algorithm results in significant improvement in visual quality. The metrics we consider are based on the same image decompositions as the corresponding compression algorithms. Such metrics are computationally efficient and considerably simpler than more elaborate metrics. However, since each of the metrics is used for the optimization of a coder, one expects that they would be biased towards that coder. We use the metrics to evaluate the performance of the compression techniques for a wide range of bit rates. Our experiments indicate that the PIC metric provides the best correlation with subjective evaluations. It predicts that at very low bit rates the SPIHT algorithm and the 8 by 8 PIC coder perform the best, while at high bit rates the 4 by 4 PIC coder is the best. More importantly, we show that the relative algorithm performance depends on image content, with the subband and DCT coders performing best for images with a lot of high frequency content, and the wavelet coders performing best for smoother images.

Citation Download Citation

Junqing Chen and Thrasyvoulos N. Pappas "Perceptual coders and perceptual metrics", Proc. SPIE 4299, Human Vision and Electronic Imaging VI, (8 June 2001); https://doi.org/10.1117/12.429485

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