Software Programs and Projects

Image Analysis and Processing Tutorial


Image analysis combines techniques that compute statistics and measurements based on the gray-level intensities of the image pixels. You can use the image analysis functions to determine whether the image quality is good enough for your inspection task. Also, you can analyze an image to understand its content and to decide which type of inspection tools to use to solve your application. Image analysis functions also provide measurements that you can use to perform basic inspection tasks such as presence or absence verification.

Common tools you can use for image analysis include histograms, line profiles, and intensity measurements.

Histogram

A histogram counts and graphs the total number of pixels at each grayscale level. Use the histogram to determine if the overall intensity in the image is suitable for your inspection task. From the histogram, you can tell whether the image contains distinct regions of a certain gray-level value. Based on the histogram data, you can adjust your image acquisition conditions to acquire higher quality images. You can detect two important criteria by looking at the histogram:

• Underexposure or saturation–Too little light in the imaging environment leads to underexposure of the imaging sensor. Too much light causes overexposure, or saturation, of the imaging sensor. Images acquired with underexposed or saturated conditions do not contain all the information that you need to inspect your object. It is important to detect these imaging conditions and correct for them during the setup of your imaging system.