Histogram

In machine vision terminology, a histogram refers to an array of pixels - how many and their individual greyscale values - within a region of interest (ROI). The In-Sight Histogram tool's functions are used to count pixels for the purposes of statistical analysis and feature classification.

In-Sight vision systems perform histogram analysis using the Histogram tool's functions:

• ExtractColorHistogram: Extracts a color histogram array from a ROI.
• ExtractHistogram: Extracts a greyscale histogram array from a ROI.
• HistContrast: Computes the contrast within the ROI.
• HistCount: Counts the number of pixels within a range of greyscale values.
• HistHead: Finds the lowest greyscale value within a range.
• HistHeadPercentage: Returns the greyscale value that is greater than the specified Percentage of pixels in the specified range of the histogram.
• HistMax: Finds the most prevalent greyscale value within a range.
• HistMean: Computes the greyscale mean value.
• HistMin: Finds the least prevalent greyscale value within a range.
• HistSDev: Computes the greyscale standard deviation.
• HistSum: Computes the sum of pixel greyscales.
• HistSumSquare: Computes the sum of pixel greyscales, squared.
• HistTail: Finds the highest greyscale value within a range.
• HistTailPercentage: Returns the greyscale value that is less than the specified Percentage of pixels in the specified range of the histogram.
• HistThresh: Computes an optimum binary threshold.