Practical Guide to Machine Vision Software: An Introduction with LabVIEW

3Particle Analysis

Particle analysis is one of the most commonly used machine vision techniques. A particle refers to connected regions (or groupings) of pixels to be measured. Particle analysis is effectively used when you want to find out the size, location, orientation, and/or number of objects in an image.

Particle analysis refers to a set of image analysis functions that operate on binary images, that is, those images that have only two values of a pixel: 1 and 0. The reason for using the binary image is that it is an easy and fast way to analyze objects by differentiating the objects (or particles) from the image background. Before particle analysis can be performed, a proper binary image needs to be created from the acquired grayscale or color image. The transformation to a binary image needs to be done in a manner such that the objects of interest in the image have pixels values of 1 and background is comprised of pixels of values 0.

Most acquired images from cameras are either color or grayscale images. Therefore, an image conversion process is needed. When a color camera is used, the acquired color image must first be converted to a grayscale image. The grayscale image is then converted to a binary image. Conversion methods will be discussed in detail later. Once the color or grayscale image is converted to binary, you may then need to apply various morphology functions prior to particle analysis. Morphology functions have the ability to effectively remove unwanted ...