基于RGB图像的泥沙颗粒粒径测试技术研究

Study on measurement technique of sediment particle size base on RGB image

针对泥沙颗粒8位灰度图像存在边缘模糊、对比度低等问题,采用RGB图像以提高泥沙颗粒图像的灰度等级和边缘灰度梯度。基于泥沙颗粒图像RGB分布特征,以直方图峰值灰度作为阈值进行图像分割,减小背景干扰;创建行搜索法,提取泥沙颗粒行中心点和行边界点;运用连通域对泥沙颗粒图像空心及局部缺失等现象进行判别填充,实现泥沙颗粒图像的精确提取。建立正方形等效法,其等效粒径为圆形等效粒径的槡π/2。应用表明,相对于8位灰度图像,RGB泥沙颗粒图像识别率更高,形态提取更完整,且正方形等效法测量结果与筛分法测量结果一致。

To counter the edge blur and contrast low of sediment particle 8- bit gray image,the RGB images were used to improve image gray scale and edge gray gradient. Comprehensive RGB histogram peak gray is employed as the threshold for image segmentation to decrease the background interference. Based on RGB gray distribution of sediment particle image,authors created the line search method,which can realizes the extraction of sediment particles and line center of boundary points. The sediment particle image integrity was enhanced with connected domain to solve the problem of hollow and partial loss. Comparison with 8- bit gray image,RGB sediment particle image recognition rate was higher,and morphology more complete,the particle size data of square equivalent method was compatible with the screening results.