| The distribution of sediment particles in water is of great significance for the study of natural rivers,reservoirs and ports.Conventional particle measurement methods do not provide a good measurement of sediment particles in water.With the rapid development of digital image processing technology,image method is also used to solve various problems of sediment particle measurement.In this paper,an underwater particle measurement system based on digital image processing is designed.The image is collected by CCD camera,and then the image is filtered,defocused particles are removed and binarized.Finally,the information of focused particles is counted to obtain the distribution of sediment particles.According to the requirements of collecting natural water images,this paper completes the overall construction of the underwater particle measurement system on the basis of selecting the appropriate hardware equipment and building the software environment.After collecting the image,several common filtering methods are analyzed.After fully considering their advantages and disadvantages,the bilateral filtering method is selected to remove the noise.Decoking particle removal is the core content of this paper.By analyzing the image,we can get the characteristic that the gray change of the edge of out of focus particles is gentle(the edge of defocused particles is blurred and the edge of focused particles is clear).According to this characteristic,a method to remove defocused particles based on the small edge gradient of defocused particles in the image is proposed.The common edge detection operators are explained in detail.Based on these operators,the algorithm to remove defocused particles is realized,and the feasibility of the algorithm is verified by the image of sediment particles After defocused particles,the image is binarized,morphological operation is carried out,and then the area and diameter of particles are counted.Simulating the natural river environment for experiments,the experimental results show that this method has the characteristics of fast treatment,miniaturization of equipment and low cost.Compared with the traditional measurement methods,the image-based underwater particle measurement system simplifies the operation steps and improves the efficiency.It is very suitable for long-term monitoring of sediment particles in natural rivers. |
