subtraction of image

基本解释

The quality of the subtraction image is improved by the multi exposure.
採用多次曝光技術，提高了相減象的質量。
The quality of the subtraction image was improved and computation time was reduced by selecting edge pixels as triangular control points.
通過計算圖像梯度信息，選取邊緣區域像素作爲控制點，既改善減影圖像質量，又提高運算速度。
Purpose: To evaluate the diagnostic value of subtraction image from ictal and interictal brain perfusion SPECT images in localization of epileptic foci.
目的：研究癲癇發作期與發作間期腦血流灌注顯像減影法定位致癲灶的價值。