[关键词]
[摘要]
图像二值化阈值的确定,直接影响二值化图像对纹理轮廓特征的表现程度,而不同中药饮片横切面图像纹理又由于复杂程度、均匀程度、粗细程度等方面存在差异,使得图像在二值化时阈值的确定存在多变性。为了能自动选取较好的二值化阈值,使得中药饮片横切面图像二值化后较好地表现其纹理轮廓特征,故提出一种基于研究图像复杂度来确定二值化阈值的方法。该方法根据二值化图像每个像素点与其相邻像素之间的同异性,确定二值化图像的复杂度,并通过研究不同阈值下二值化图像复杂度的变化来确定阈值。本文选取在饮片切片纹理上具有代表性的槟榔、苍术、地榆、甘草、黄芪5种中药饮片做为研究载体,涉及放射状纹理、散点状纹理、环状纹理,探讨并提出一种二值化阈值的确定方法——邻域法。实验结果证明利用邻或法所求阈值的二值化图像能较好地表现中药饮片横切面图像纹理轮廓特征。
[Key word]
[Abstract]
The resolution of contour feature of images directly relies on the optimization and determination of the threshold value in image binaryzation process. However, the binaryzation threshold value of an image has turned out to be rather flexible as cross-section of Chinese herbal pieces varies dramatically in terms of complexity, evenness and shape. It is meaningful to develop a method to definitely choose a proper threshold value in order to portray the contour feature of cross-section texture images of Chinese herbal pieces clearly after the image binaryzation process when it comes to image pattern recognition. A method based on image complexity research was proposed to determine a proper value of binaryzation. In this method, the binaryzation threshold value varies with the variation of image complexity, while the image complexity was determined according to differences between one pixel and its neighborhoods of an image. The result showed that binaryzation images whose threshold value derived from the method proposed in this study were well able to depict the features of cross-section texture of Chinese herbal pieces.
[中图分类号]
[基金项目]
北京中医药大学科研基金课题(2009-X-11):中药材标本三维可视化模型构建方法研究,负责人:陶欧。