岩石中不同矿物的形状变化反映了岩石的变形破坏过程。在分析花岗岩试样表面图像不同矿物纹理特征基础上，使用室内单轴压缩试验视频图像和灰度分界阈值分割法，研究了单帧图像中不同矿物的分布特征，使用形状参数描述了岩石变形过程中不同成分的形状特征，探讨了不同成分区域形状变化与裂隙扩展过程的关系。结果表明，花岗岩变形过程中圆形度的大小顺序为长石＞黑云母＞石英，内切圆半径的大小顺序为黑云母＞长石＞石英；离散指数的大小顺序为长石＞石英＞黑云母；长石承受了轴向力的主要部分，形状变化与所处位置关系较大；破坏过程中裂隙面积出现大小顺序为长石、石.英、黑云母，裂隙扩展较快时裂隙大多出现在长石和石英区域。

The shape changes of the minerals on the surface reflect the deformation/failure process of the rock material. In the current study, after analyzing the textual features of various mineral regions on a granite specimen surface, the video images photographed during the laboratory uniaxial compression test and the grayscale threshold segmentation were used to investigate the distributions of the minerals in each frame. The shape parameters were extracted from the frame to depict the configuration features of various compositions at any time during the deformations of the rock. The relations between the changes in shape parameters of various compositions and the propagation process of cracks were further explored. It is shown that during the deformation of the granite under the external load, the magnitude sequence of the circularity is feldspar, biotite, and quartz; that of the inscribed circle radius is biotite, feldspar, and quartz; and that of the variance index is feldspar, biotite, and quartz; the feldspar region beard the most part of the axial load; and the shape changes of the feldspar regions are much depended on the actual locations; during the failure of the specimen; the magnitude sequences of the areas are feldspar, quartz, and biotite where new cracks generated; and the most of the cracks propagated on the feldspar and quartz regions if the cracks developed quickly.