医学成像与通信协议DICOM影像在各种显示介质上的一致性学术报告精要.ppt

* * 9 * 10 DICOM Singapore Seminar: Consistent Presentation of Images: The Grayscale Image Presentation Problem: The appearance of grayscale images displayed on different types of softcopy display devices or printed on different types of hardcopy output devices has often been inconsistent. Optimal image viewing parameters (e.g. window/ level) selected on one device appear different when displayed on a different device Device capabilities/ characteristics vary - the same number of gray levels cannot be rendered or perceived on different devices Displayed images look different from printed images …other The Grayscale Consistency Problem: Problems of Inconsistency mass visible mass invisible VOI chosen on one display device Rendered on another with different display Mass expected to be seen is no longer seen Slide Provided by David Clunie, Quintiles Intelligent Imaging Problems of Inconsistency 0.5 1.5 1.0 3.0 Not all display levelsare perceivable on alldevices Slide Provided by David Clunie, Quintiles Intelligent Imaging Problems of Inconsistency 0.5 1.5 1.0 3.0 Not all display levelsare perceivable on alldevices Slide Provided by David Clunie, Quintiles Intelligent Imaging Problems of Inconsistency Digital Modality Laser Printer Printed images don’t looklike displayed images Slide Provided by David Clunie, Quintiles Intelligent Imaging Causes of Inconsistency Gamut of device Minimum/maximum luminance/density Characteristic curve Mapping digital input to luminance/density Shape Linearity Ambient light or illumination Causes of Inconsistency 1.0 .66 Display devicesvary in the maximumluminance they canproduce Display CRT vs. film on a light box is an extreme example Slide Provided by David Clunie, Quintiles Intelligent Imaging Towards a Standard Display Can’t use absolute luminance since display capabilities different Can’t use relative luminance since shape of characteristic curves vary Solution: exploit known characteristics of the contrast sensitivity o