自适应最小误差阈值分割算法

Adaptive Minimum Error Thresholding Algorithm

对二维最小误差法进行三维推广,并结合三维直方图重建和降维思想提出了一种鲁棒的最小误差阈值分割算法.但该方法为全局算法,仅适用于分割均匀光照图像.为提高其自适应性,本文采用Waterflow模型对非均匀光照图像进行背景估计,以此获得原始图像与背景图像的差值图像,达到降低非均匀光照对图像分割造成干扰的目的.为进一步提高分割性能,本文对差值图像采用γ矫正进行增强,然后采用鲁棒最小误差法进行全局分割,从而完成目标提取.最后本文对均匀光照下以及非均匀光照下图像进行了实验,并与一维最小误差法、二维最小误差法、三维直方图重建和降维的Otsu阈值分割算法、灰度波动变换自适应阈值方法以及一种改进的FCM方法在错误分割率和运行时间上进行了对比.实验结果表明,相对于以上方法,本算法的分割性能均有明显提升.

A robust minimum error thresholding method is proposed to combine the three-dimensional （3D） minimum error thresholding scheme based on 2D method with the principle of rebuilding and dimension reduction of the 3D histogram. Considering the global behavior of this approach and its ability to process even illumination images only, a water flow model is used to estimate the background of uneven illumination images for improving adaptability of the proposed method. Then, the difference image between the original image and background can be readily obtained to reduce the interference of uneven illumination during the binarization process. To improve execution performance of the segmentation procedure, gamma correction is employed to enhance image in addition to a global segmentation using robust minimum error thresholding algorithm. Subsequently, image segmentation tests are carried out with even and uneven illumination, and then comparison on misclassification error and time expenditure are performed between the proposed method and other approaches, i.e., 1D/2D minimum error thresholding, Otsu thresholding algorithm based on 3D histogram rebuilding and dimensionality reduction, adaptive gray wave transformation thresholding scheme, as well as a modified FCM method. The results show that the proposed approach yields better thresholding performance than those methods.