To Manage Image By Grayscale Enhancement And Its Application In Image Diagnosis

To Manage Image By Grayscale Enhancement And Its ApplicationIn Image DiagnosisNowadays, medical imageology become the key point in modern clinicaldiagnosis, radiation treatment, research and teaching. With several image processingmethods are widely confirmed, the application of digital image information gets moreand more widely applied. Since the assistance of computer technology in diagnosisand examination could improve the efficiency and correctness of image diagnosis, itis of the bright development future. Image processing technology began fromprocessing the photos received from space in early 60th, and now it is widely used inseveral fields such as remote sensing, military affairs and so on. As image processingtechnology could help quantificationally analyze various tissues and structures inmedical photos and could automatically classify and identify different tissues, it isnecessary for modem medicine development.With the rapidly development of medical image equipments, the imagingresolution, speed and information capacity are continuously optimized. However, since the contrast ratio for different organs and tissues are still relatively low, thevisual effect is not satisfied. The reason primarily lies on the visual property forhuman eyes, which has a certain brightness response field, about 40/256 grayscale.Because there is the rim enhancement effect in retina, the resolution will reach128/256 or more while the grayscale transition band is obvious. On the contrary, while the rim fuse, the resolution will decrease lower than 40/256 since the rimenhance effect disappear, the distinction totally depends on the grayscale.To some MRI and CT photos, the contrast is too low to distinguish thepathological field from the normal filed. The quality of the photos could be significantly enhanced if the grayscale enhance processing is applied. There are twomethods: grayscale transformation and algorithm using histogram. In this experiment, This method of math designed asymmetrical and nonlinear mapping by grayscaleslices is used to compensate for the gray-vision response simultaneously. The purposeis to test the method which could enhance signals from pathological field in CT andMRI photos, to support the automatically screening of pathological field.The resultshows us, this method could enhance the signal intensity in pathological field whichhas the tiny gray difference in the CT and MRI photos.