Paper
6 April 2005 Visually lossless compression of digitized radiographs based on contrast sensitivity and visual masking
Damon Michael Chandler, Nathan L. Dykes, Sheila S. Hemami
Author Affiliations +
Abstract
A visually lossless compression algorithm for digitized radiographs, which predicts the maximum contrast that wavelet subband quantization distortions can exhibit in the reconstructed image such that the distortions are visually undetectable, is presented. Via a psychophysical experiment, contrast thresholds were measured for the detection of 1.15-18.4 cycles/degree wavelet subband quantization distortions in five digitized radiographs; results indicate that digitized radiographs impose image- and frequency-selective effects on detection. A quantization algorithm is presented which predicts the thresholds for individual images based on a model of visual masking. When incorporated into JPEG-2000 and applied to a suite of images, results indicate that digitized radiographs can be compressed in a visually lossless manner at an average compression ratio of 6.25:1, with some images requiring visually lossless ratios as low as 4:1 and as great as 9:1. The proposed algorithm thus yields images that require the minimum bit-rate such that the reconstructed images are visually indistinguishable from the original images. The primary utility of the proposed algorithm is its ability to provide image-adaptive visually lossless compression, thereby avoiding overly conservative or overly aggressive compression.
© (2005) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Damon Michael Chandler, Nathan L. Dykes, and Sheila S. Hemami "Visually lossless compression of digitized radiographs based on contrast sensitivity and visual masking", Proc. SPIE 5749, Medical Imaging 2005: Image Perception, Observer Performance, and Technology Assessment, (6 April 2005); https://doi.org/10.1117/12.595614
Lens.org Logo
CITATIONS
Cited by 25 scholarly publications and 8 patents.
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Image compression

Visualization

Visual compression

Quantization

Radiography

Wavelets

Discrete wavelet transforms

Back to Top