Visual increment and decrement threshold curves as a function of luminance range and noise in simulated computed tomographic scans.
Visual increment and decrement threshold curves as a function of luminance range and noise in simulated computed tomographic scans.
复制标题
视觉增量和减量阈值曲线作为模拟计算机断层扫描中亮度范围和噪声的函数。
DOI：
10.1097/00004424-199208000-00007
复制
发表时间：
1992
影响因子：
6.7
通讯作者：
Pizer,SM
中科院分区：
文献类型：
--
作者：
Klymenko,V;Johnston,RE;Pizer,SM
目标.在8个实验中研究了亮度范围压缩对计算机断层扫描（CT）中目标视觉阈值的影响。获得了热目标的视觉增量阈值和冷目标的视觉减量阈值。模拟扫描重建和部分体积模糊的现实噪声CT图像作为复杂医学图像的代表进行了测试。这些CT图像的负版本、高亮度版本和无噪声版本也进行了测试。在所有含噪图像中，由于图像亮度范围被压缩，目标与其局部背景之间的物理亮度差需要相应地较小才能达到视觉阈值。然而，就靶和背景之间的CT数差异而言，阈值相同。CT数方面的噪声为各种显示条件设置阈值。在无噪声CT中，由于亮度范围被压缩，目标和背景之间需要达到阈值的亮度差也减小，但仅是略微减小。然而，在CT数量方面，阈值增加。
OBJECTIVES. The effect of luminance range compression on the visual threshold of a target in a computed tomographic (CT) scan was investigated in eight experiments.METHODS. Both visual increment thresholds of a hot target and visual decrement thresholds of a cold target were obtained. Realistic noisy CT images simulating a scan reconstruction and partial volume blurring were tested as representative of complex medical images. Negative versions, high luminance versions, and noise-free versions of these CT images also were tested.RESULTS AND CONCLUSIONS. In all the noisy images, as the luminance range of the image was compressed, proportionately smaller physical luminance differences between the target and its local background were needed to reach visual threshold. However, the thresholds were the same in terms of the difference in CT numbers between target and background. Noise in terms of CT numbers sets the threshold for a wide range of display conditions. In the noise-free CTs, as the luminance range was compressed, the luminance differences between the target and background needed to reach threshold also decreased, but only marginally. However, in terms of CT numbers, the thresholds were increased.