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RISS 인기검색어
- 검색키워드
- 저자 : Mantiuk, Rafal (검색결과 4 건)
- 무료
- 기관 내 무료
- 유료
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Kil Joong Kim,Bohyoung Kim,Mantiuk, Rafal,Richter, Thomas,Hyunna Lee,Heung-Sik Kang,Jinwook Seo,Kyoung Ho Lee IEEE 2010 IEEE transactions on medical imaging Vol.29 No.8
<P>This study aimed to evaluate three image fidelity metrics of different computational principles-peak signal-to-noise ratio (PSNR), high-dynamic range visual difference predictor (HDR-VDP), and multiscale structural similarity (MS-SSIM)-in measuring the fidelity of JPEG2000 compressed abdomen computed tomography images from a viewpoint of visually lossless compression. Three hundred images with 0.67- or 5-mm section thickness were compressed to one of five compression ratios ranging from reversible compression to 15:1. The fidelity of each compressed image was measured by five radiologists' visual analyses (distinguishable or indistinguishable from the original) and the three metrics. The Spearman rank correlation coefficients of the PSNR, HDR-VDP, and MS-SSIM values with the number of readers responding as indistinguishable were 0.86, 0.94, and 0.86, respectively. Using the pooled readers' responses as the reference standard, the area under the receiver-operating-characteristic curve for the HDR-VDP (0.99) was significantly greater than that for the PSNR (0.95) (<I>p</I> <; 0.001) and for the MS-SSIM (0.96) (<I>p</I> = 0.003), and there was no significant difference between the PSNR and MS-SSIM (<I>p</I> = 0.70). In measuring the image fidelity, the HDR-VDP outperforms the PSNR and MS-SSIM, and the MS-SSIM and PSNR are comparable.</P>
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Kim, Bohyoung,Lee, Kyoung Ho,Kim, Kil Joong,Mantiuk, Rafal,Kim, Hye-ri,Kim, Young Hoon American Roentgen Ray Society, etc.] 2008 American Journal of Roentgenology Vol.190 No.6
<P>OBJECTIVE: The objective of our study was to assess the effects of compressing source thin-section abdominal CT images on final transverse average-intensity-projection (AIP) images. MATERIALS AND METHODS: At reversible, 4:1, 6:1, 8:1, 10:1, and 15:1 Joint Photographic Experts Group (JPEG) 2000 compressions, we compared the artifacts in 20 matching compressed thin sections (0.67 mm), compressed thick sections (5 mm), and AIP images (5 mm) reformatted from the compressed thin sections. The artifacts were quantitatively measured with peak signal-to-noise ratio (PSNR) and a perceptual quality metric (High Dynamic Range Visual Difference Predictor [HDR-VDP]). By comparing the compressed and original images, three radiologists independently graded the artifacts as 0 (none, indistinguishable), 1 (barely perceptible), 2 (subtle), or 3 (significant). Friedman tests and exact tests for paired proportions were used. RESULTS: At irreversible compressions, the artifacts tended to increase in the order of AIP, thick-section, and thin-section images in terms of PSNR (p < 0.0001), HDR-VDP (p < 0.0001), and the readers' grading (p < 0.01 at 6:1 or higher compressions). At 6:1 and 8:1, distinguishable pairs (grades 1-3) tended to increase in the order of AIP, thick-section, and thin-section images. Visually lossless threshold for the compression varied between images but decreased in the order of AIP, thick-section, and thin-section images (p < 0.0001). CONCLUSION: Compression artifacts in thin sections are significantly attenuated in AIP images. On the premise that thin sections are typically reviewed using an AIP technique, it is justifiable to compress them to a compression level currently accepted for thick sections.</P>
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Kim, Bohyoung,Lee, Kyoung Ho,Kim, Kil Joong,Mantiuk, Rafal,Hahn, Seokyung,Kim, Tae Jung,Kim, Young Hoon American Roentgen Ray Society, etc.] 2008 American Journal of Roentgenology Vol.190 No.2
<P>OBJECTIVE: The objective of our study was to determine whether peak signal-to-noise ratio (PSNR) and a perceptual quality metric (High-Dynamic Range Visual Difference Predictor [HDR-VDP]) can predict the presence of perceptible artifacts in Joint Photographic Experts Group (JPEG) 2000-compressed chest CT images. MATERIALS AND METHODS: One hundred chest CT images were compressed to 5:1, 8:1, 10:1, and 15:1. Five radiologists determined if the original and compressed images were identical (negative response) or different (positive response). The correlation between the results for each metric and the number of readers with positive responses was evaluated using Spearman's rank correlation test. Using the pooled readers' responses as the reference standard, we performed receiver operating characteristic (ROC) analysis to determine the cutoff values balancing sensitivity and specificity and yielding 100% sensitivity in each metric. These cutoff values were then used to estimate the visually lossless thresholds for the compressions for the 100 original images, and the accuracy of the estimates of two metrics was compared (McNemar test). RESULTS: The correlation coefficients were -0.918 and 0.925 for PSNR and the HDR-VDP, respectively. The areas under the ROC curves for the two metrics were 0.983 and 0.984, respectively (p = 0.11). The PSNR and HDR-VDP accurately predicted the visually lossless threshold for 69% and 72% of the 100 images (p = 0.68), respectively, at the cutoff values balancing sensitivity and specificity and for 43% and 47% (p = 0.22), respectively, at the cutoff values reaching 100% sensitivity. CONCLUSION: Both metrics are promising in predicting the perceptible compression artifacts and therefore can potentially be used to estimate the visually lossless threshold.</P>
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Kim, Kil Joong,Kim, Bohyoung,Lee, Kyoung Ho,Mantiuk, Rafal,Richter, Thomas,Kang, Heung Sik RSNA 2013 Radiology Vol.268 No.3
<P>Among the five tested image features, variation in high-frequency energy and visual complexity were promising in predicting the visually lossless thresholds of body CT images for JPEG2000 compression.</P>
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