Clinical evaluation of irreversible image compression: analysis of chest imaging with computed radiography.

Abstract

To implement a picture archiving and communication system, clinical evaluation of irreversible image compression with a newly developed modified two-dimensional discrete cosine transform (DCT) and bit-allocation technique was performed for chest images with computed radiography (CR). CR images were observed on a cathode-ray-tube monitor in a 1,024 X 1,536 matrix. One original and five reconstructed versions of the same images with compression ratios of 3:1, 6:1, 13:1, 19:1, and 31:1 were ranked according to quality. Test images with higher spatial frequency were ranked better than those with lower spatial frequency and the acceptable upper limit of the compression ratio was 19:1. In studies of receiver operating characteristics for scoring the presence or absence of nodules and linear shadows, the images with a compression ratio of 25:1 showed a statistical difference as compared with the other images with a compression ratio of 20:1 or less. Both studies show that plain CR chest images with a compression ratio of 10:1 are acceptable and, with use of an improved DCT technique, the upper limit of the compression ratio is 20:1.

Visually Lossless Threshold: JPEG 2000 compression of Digital Chest Radiographs

“…Most previous studies have concerned the diagnostically lossless threshold (7)(8)(9)16). However, image compression artifacts can be detectable even though their presence does not affect the reader's performance for a given diagnostic task (9,10,17).…”

“…The acceptable compression ratios were reported to be as high as between 10:1 and 25:1 (7)(8)(9)16). All published reports on studies concerned the evaluation of diagnostic performance -the diagnostic lossless threshold -typically in a receiver operating characteristic study.…”

An Improved Visual Pruning Algorithm for Perceptually Lossless Medical Image Coding

“…where m and n are the spatial frequency coordinate of a coefficient, E Z,l,θ [m, n] and I Z,l,θ [m, n] are excitation and inhibition functions, k Z and γ q Z are the scaling and saturation constants, Z {Θ, Υ}, with Θ and Υ specifying the inter-orientation and intra-frequency masking domains, respectively 3 . l = {1, 2, 3, 4, 5} and θ = {1, 2, 3} represent the frequency levels and the orientation bands, respectively.…”

“…This paper focuses on grayscale images. 3 Inter-frequency masking was omitted to simplify the model. …”

A New Diagnosis Loseless Compression Method for Digital Mammography Based on Multiple Arbitrary Shape ROIs Coding Framework

“…It is estimated that approximately 10%-30% of breast cancer cases are missed by radiologists [1] [2]. Computer-aid diagnosis (CAD) systems have been widely used to help improve the detection precision [5] [6]. Diagnosis information of digital mammography need be saved losslessly in CAD.…”