Count Pixels FAQs

Q: How do I use Lower Limit and Upper Limit?

When you select an automatic threshold method, the algorithm attempts to split the histogram of pixel intensities in the region of interest into two classes. During a typical inspection process, acquired images may differ greatly from what the algorithm is expecting. For example, you could be working with an image representing a bright object on a dark background in which the object is unexpectedly missing from the inspected region of interest. An automatic thresholding algorithm might still segment the dark background into two intensity classes and, as a result, return an incorrect threshold level that includes an incorrect number of bright pixels. To prevent this, use Lower Limit and Upper Limit to coerce the threshold values to define a range that includes only the expected variations that would occur in a typical inspection.