Image Segmentation Technique Used in Estimation of the Size Distribution of Rock Fragments in Mining

In this paper we describe a method for segmenting the image of fragmented ore into regions and estimating a size distrubution of the ore fragments. As the image grey level is inadequate for determining the rock boundary, we propose a two-step method for segmentation. First step, apply a region growing algorithm to construct a primary region division from the image grey level. Second step, use a set of rules to examine the region shapes and correct the division errors. Features of the regions, which are relative to the rock volume, are then measured. The method is simple and economic, while the precision is acceptable. within the rock extent. Segmentation method based on neighborhood grey level will not be able to outline each rock. Some progress has already been achieved in analyzing the ore fragment image. There are systems and methods proposed in U. Lulea (in Sweden) developed a system for automatic processing of fragment image [61. The system equiped with a microprocessor and a TV camera. .It can directly process image in the mining site. The method of processing is that use a Sobel operator to detect edges, reinforce them by iteration, then extract the random diameters (line segment bounded by edges) as the feature. This method avoided the difficulty of segmentation into regions. But it can not solve the problem that the sudden change of grey level does not correspond to the rock boundary. INTRODUCTION ANALYSIS OF THE PROBLEU Image segmentation is a process of dividing an input image into several distinct regions of uniform properties, such as intensity , color and texture. It is a fundamental subject of computer image processing and computer vision. The image segmentation techniques can be catagorized into following groups: grey value thresholding; edge detection and boundary following; region growing; texture analysis and shape analysis. These methods are often effectively used in many application areas of image processing. In this paper we introduce a segmentation method applied in analyzing the size distribution of ore fragments in mining. The fragmentation of rock is a primary objective in many mining processes. In order to achieve proper control it is essential that rapid measurements of the size distribution of the resulting rock fragments can be performed. The efficiency of the entire process can be largely depending on the availability of such measurements. The size means the volume of a rock. While in estimation, however, we can use …