# Documentation

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# Statistics

Statistical operations, and blob anaylsis

## System Objects

 `vision.Autocorrelator` Compute 2-D autocorrelation of input matrix `vision.BlobAnalysis` Properties of connected regions `vision.Crosscorrelator` 2-D cross-correlation of two input matrices `vision.LocalMaximaFinder` Find local maxima in matrices `vision.Maximum` Find maximum values in input or sequence of inputs `vision.Mean` Find mean value of input or sequence of inputs `vision.Median` Find median values in an input `vision.Minimum` Find minimum values in input or sequence of inputs `vision.StandardDeviation` Find standard deviation of input or sequence of inputs `vision.Variance` Find variance values in an input or sequence of inputs

## Blocks

 2-D Autocorrelation Compute 2-D autocorrelation of input matrix 2-D Correlation Compute 2-D cross-correlation of two input matrices 2-D Histogram Generate histogram of input or sequence of inputs 2-D Maximum Find maximum values in input or sequence of inputs 2-D Mean Find mean value of each input matrix 2-D Median Find 2-D Median value of each input matrix 2-D Minimum Find minimum values in input or sequence of inputs 2-D Standard Deviation Find standard deviation of each input matrix 2-D Variance Compute variance of input or sequence of inputs Blob Analysis Compute statistics for labeled regions Find Local Maxima Find local maxima in matrices PSNR Compute peak signal-to-noise ratio (PSNR) between images

## Topics

### MATLAB Workflow

Cell Counting

This example shows how to use a combination of basic morphological operators and blob analysis to extract information from a video stream.

Object Counting

This example shows how to use morphological operations to count objects in a video stream.

Find the Histogram of an Image

The Histogram block computes the frequency distribution of the elements in each input image by sorting the elements into a specified number of discrete bins.

Correct Nonuniform Illumination

Use the Opening block to correct for uneven lighting in an image.