针对目前基于工业CT图像的岩心孔隙计算中都采用局部自定义区域数据的问题,提出了一种基于岩心图像全部数据的孔隙率计算方法。其中,岩心目标的准确提取是该方法的关键。研究了图像中岩心目标与周边噪音的结构和位置关系,并以此为依据提出了一种工业CT图像的岩心目标提取算法。然后以CT图像中的岩心目标为数据源,通过目标内的孔隙像素与目标像素之比来计算单张图像的岩心孔隙率。而针对岩心的序列CT图像,则通过计算每张图像的孔隙率均值来获得该岩心的孔隙率。最后,以一岩心样本的CT序列图像为例,说明所提方法的准确性和有效性。

A calculation method of core porosity based on core target data is proposed as a strategy to solve the problems caused by the current method based on industrial CT images which usually uses local region in images. The key of this method lies in the accurate extraction of the core target from industrial CT images. On the basis of a research of the structure and position relations of the core target and ambient noises in CT images, an effective method is proposed to accurately extract core target from industrial CT images. According to this method, the core porosity of a single CT image can be obtained by calculating the ratio of pore pixels to target pixels, with core target in industrial CT images used as data source. As for the core porosity based on a sequence of CT images, it can appeal to the calculation of the mean value of core porosity of each image in this sequence. Finally, this paper illustrates the accuracy and effectiveness of the method proposed in this research with an example of core porosity calculation based on a sequence of industrial CT images of a core sample.