Video compression of coronary angiograms based on discrete wavelet transform with block classification

Abstract

A new method of video compression for angiographic images has been developed to achieve high compression ratio (~20:1) while eliminating block artifacts which leads to loss of diagnostic accuracy. This method adopts motion picture experts group's (MPEGs) motion compensated prediction to takes advantage of frame to frame correlation. However, in contrast to MPEG, the error images arising from mismatches in the motion estimation are encoded by discrete wavelet transform (DWT) rather than block discrete cosine transform (DCT). Furthermore, the authors developed a classification scheme which label each block in an image as intra, error, or background type and encode it accordingly. This hybrid coding can significantly improve the compression efficiency in certain eases. This method can be generalized for any dynamic image sequences applications sensitive to block artifacts.

Coronary angiogram video compression for remote browsing and archiving applications

“…In contrast to MPEG, the error images arising from mismatches in the ME are encoded by discrete wavelet transform (DWT) rather than block discrete cosine transform (DCT). The obtained results suggest that approaches based on the full-frame DWT have strong promise to provide both high image quality and high compression, of about 20:1, when applied to coronary angiograms [4]. However the developed methods are premature to make conclusions regarding acceptable compression ratios in the absence of clinical assessment.…”

“…Other approaches [2,4] adopt MPEGs motion compensated prediction to take advantage of frame to frame correlation. In contrast to MPEG, the error images arising from mismatches in the ME are encoded by discrete wavelet transform (DWT) rather than block discrete cosine transform (DCT).…”

“…the edge of coronary arteries), mainly because of the scattered radiation and the motion blur of the heart. All of these reasons brought up the researchers to define new compression approaches more adapted to dynamic coronary angiogram video [2][3][4][5][6]. These methods are acceptable for clinical decision-making.…”

Coronary angiogram video compression using wavelet-based contourlet transform and region-of-interest technique

“…This is because FFDCT is a frequency-isolating technique not suitable for spatially concentrated block artefacts. Another approach [2] adopts MPEGs motion compensated prediction to take advantage of frame-to-frame correlation. In contrast to MPEG, the error images arising from mismatches in the ME are encoded by a discrete wavelet transform (DWT) rather than block DCT.…”

Wavelet compression of ultrasound video streams for teleradiology

“…The standards for still (JPEG) and video (MPEG) image compression produce well-known "blocking" artifacts under heavy compression, due to their block-oriented partitioning of each image. Wavelet compression techniques, on the other hand, do not produce block artifacts under lossy compression, and have found acceptance in such diverse fields as digital coronary angiography [3] and fingerprint archiving (FBI Quantification of image quality degradation has a rich history in image processing and has involved a variety of metrics. Our group is developing the tools to apply both numerical figures-of-merit and more subjective receiver operating characteristic (ROC) type analyses, involving jury tests with experienced sonographers, to video clips, using wherever possible commercial solutions and off-the-shelf software.…”