At the University of Arizona a research project is underway which addresses consistent color and ... more At the University of Arizona a research project is underway which addresses consistent color and consistent gray-scale reproduction for digital color displays used in medical image interpretation, specifically for Pathology. Now the University of Arizona can enter the field of ICC Profiling and Color Management. Of particular interest are Verification of PerfectLum Software, conformance and deviation and the maximum GSDF
ABSTRACT A methodology and associated software modules for calibration, characterization and prof... more ABSTRACT A methodology and associated software modules for calibration, characterization and profiling of color LCDs for color-critical applications such as medical imaging is described. Supporting analyses reveal very high color reproduction accuracy as determined by CIE DE2000 color differences for 210 test colors uniformly distributed in CIE Lab color space.
At the University of Arizona a research project is underway which addresses consistent color and ... more At the University of Arizona a research project is underway which addresses consistent color and consistent gray-scale reproduction for digital color displays used in medical image interpretation, specifically for Pathology. Now the University of Arizona can enter the field of ICC Profiling and Color Management. Of particular interest are Verification of PerfectLum Software, conformance and deviation and the maximum GSDF Error. Verification of PerfectLum Software seemed to be successful. FIT and LUM tests were performed to verify the conformance and the deviation was quantified. The maximum GSDF Error turned out to depend slightly on the bandwidth of the PR-670 Spectrophotometer. Measurements were made at two settings each of Normal and Fast. At the setting "Normal" the maximum GSDF Errors were 8.6% and 6.1 %. At the setting "Fast" the maximum GSDF Errors were 7.44 % and 5.76%. With respect to the results, all three objectives were met and the PerfectLum calibrated display was confirmed to the AAPM TG18 standards.
Our laboratory has investigated the efficacy of a suite of color calibration and monitor profilin... more Our laboratory has investigated the efficacy of a suite of color calibration and monitor profiling packages which employ a variety of color measurement sensors. Each of the methods computes gamma correction tables for the red, green and blue color channels of a monitor that attempt to: a) match a desired luminance range and tone reproduction curve; and b) maintain a target neutral point across the range of grey values. All of the methods examined here produce International Color Consortium (ICC) profiles that describe the color rendering capabilities of the monitor after calibration. Color profiles incorporate a transfer matrix that establishes the relationship between RGB driving levels and the International Commission on Illumination (CIE) XYZ (tristimulus) values of the resulting on-screen color; the matrix is developed by displaying color patches of known RGB values on the monitor and measuring the tristimulus values with a sensor. The number and chromatic distribution of color patches varies across methods and is usually not under user control. In this work we examine the effect of employing differing calibration and profiling methods on rendition of color images. A series of color patches encoded in sRGB color space were presented on the monitor using color-management software that utilized the ICC profile produced by each method. The patches were displayed on the calibrated monitor and measured with a Minolta CS200 colorimeter. Differences in intended and achieved luminance and chromaticity were computed using the CIE DE2000 color-difference metric, in which a value of ΔE = 1 is generally considered to be approximately one just noticeable difference (JND) in color. We observed between one and 17 JND's for individual colors, depending on calibration method and target. As an extension of this fundamental work1, we further improved our calibration method by defining concrete calibration parameters for the display, using the NEC wide gamut puck, and making sure that those calibration parameters did conform, with the help of a state of the art Spectroradiometer, PR670. As a result of this addition of the PR670, and also an in-house developed method of profiling and characterization, it appears that there was much improvement in ΔE, the color difference.
At the University of Arizona a research project is underway which addresses consistent color and ... more At the University of Arizona a research project is underway which addresses consistent color and gray-scale reproduction for digital color displays used in medical image interpretation. Now the University of Arizona can enter the field of ICC Profiling and Color Management. A color calibration facility was developed from ground up. Color calibration is presented for three color LCDs as is color accuracy. A PR670 Spectroradiometer was used to correct for errors of the pucks. A method was used to calculate the color accuracy and the DeltaE values.
At the University of Arizona a research project is underway which addresses consistent color and ... more At the University of Arizona a research project is underway which addresses consistent color and consistent gray-scale reproduction for digital color displays used in medical image interpretation, specifically for Pathology. Now the University of Arizona can enter the field of ICC Profiling and Color Management. Of particular interest are Verification of PerfectLum Software, conformance and deviation and the maximum GSDF
ABSTRACT A methodology and associated software modules for calibration, characterization and prof... more ABSTRACT A methodology and associated software modules for calibration, characterization and profiling of color LCDs for color-critical applications such as medical imaging is described. Supporting analyses reveal very high color reproduction accuracy as determined by CIE DE2000 color differences for 210 test colors uniformly distributed in CIE Lab color space.
At the University of Arizona a research project is underway which addresses consistent color and ... more At the University of Arizona a research project is underway which addresses consistent color and consistent gray-scale reproduction for digital color displays used in medical image interpretation, specifically for Pathology. Now the University of Arizona can enter the field of ICC Profiling and Color Management. Of particular interest are Verification of PerfectLum Software, conformance and deviation and the maximum GSDF Error. Verification of PerfectLum Software seemed to be successful. FIT and LUM tests were performed to verify the conformance and the deviation was quantified. The maximum GSDF Error turned out to depend slightly on the bandwidth of the PR-670 Spectrophotometer. Measurements were made at two settings each of Normal and Fast. At the setting "Normal" the maximum GSDF Errors were 8.6% and 6.1 %. At the setting "Fast" the maximum GSDF Errors were 7.44 % and 5.76%. With respect to the results, all three objectives were met and the PerfectLum calibrated display was confirmed to the AAPM TG18 standards.
Our laboratory has investigated the efficacy of a suite of color calibration and monitor profilin... more Our laboratory has investigated the efficacy of a suite of color calibration and monitor profiling packages which employ a variety of color measurement sensors. Each of the methods computes gamma correction tables for the red, green and blue color channels of a monitor that attempt to: a) match a desired luminance range and tone reproduction curve; and b) maintain a target neutral point across the range of grey values. All of the methods examined here produce International Color Consortium (ICC) profiles that describe the color rendering capabilities of the monitor after calibration. Color profiles incorporate a transfer matrix that establishes the relationship between RGB driving levels and the International Commission on Illumination (CIE) XYZ (tristimulus) values of the resulting on-screen color; the matrix is developed by displaying color patches of known RGB values on the monitor and measuring the tristimulus values with a sensor. The number and chromatic distribution of color patches varies across methods and is usually not under user control. In this work we examine the effect of employing differing calibration and profiling methods on rendition of color images. A series of color patches encoded in sRGB color space were presented on the monitor using color-management software that utilized the ICC profile produced by each method. The patches were displayed on the calibrated monitor and measured with a Minolta CS200 colorimeter. Differences in intended and achieved luminance and chromaticity were computed using the CIE DE2000 color-difference metric, in which a value of ΔE = 1 is generally considered to be approximately one just noticeable difference (JND) in color. We observed between one and 17 JND's for individual colors, depending on calibration method and target. As an extension of this fundamental work1, we further improved our calibration method by defining concrete calibration parameters for the display, using the NEC wide gamut puck, and making sure that those calibration parameters did conform, with the help of a state of the art Spectroradiometer, PR670. As a result of this addition of the PR670, and also an in-house developed method of profiling and characterization, it appears that there was much improvement in ΔE, the color difference.
At the University of Arizona a research project is underway which addresses consistent color and ... more At the University of Arizona a research project is underway which addresses consistent color and gray-scale reproduction for digital color displays used in medical image interpretation. Now the University of Arizona can enter the field of ICC Profiling and Color Management. A color calibration facility was developed from ground up. Color calibration is presented for three color LCDs as is color accuracy. A PR670 Spectroradiometer was used to correct for errors of the pucks. A method was used to calculate the color accuracy and the DeltaE values.
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