针对活塞内冷油腔测量的难题，提出了基于CT图像的油腔自动测量方法。通过工业CT扫描获取活塞内冷油腔横截面图像，利用图像处理方法提取油腔变形程度和位置，以此对活塞油腔质量进行量化评价。采用最大类间方差法与中值滤波对图像进行预处理，有效地解决了油腔内、外环边缘提取的问题。使用LabVIEW编制批处理软件，并通过解剖测量活塞油腔进行对比试验。试验结果表明：所提出的基于图像处理的油腔自动测量方法稳定可靠，实现了活塞内冷油腔的快速、精确测量，为实现对活塞内冷油腔质量评判提供了量化依据。

Aiming at the problem of automatic measurement of piston oil chamber，this paper studies an piston oil chamber image measuring method based on CT image．In order to evaluate the quality of each piston oil chamber，an industrial CT is used to obtain the piston oil chamber information and extract the distortion and position of oil reservoir through image processing． Considering the problem that the oil chamber affects the image edge detection precision， maximum variance separate method and median filtering method are adopted to preprocess the image．The software LabVIEW was used to authors measuring softwere, and the piston was dissected to measure oil chamber as comparative experiment. Experiment results show that the proposed method based on CT image is stable and reliable，high precision measuring of piston oil chamber is achieved，which makes a quality evaluation for piston oil chamber automatic measurement．