step

System object: vision.Variance
Package: vision

Compute variance of input

Syntax

Y = step(H,X)
Y = step(H,X,R)
Y = step(H,X,ROI)
Y = step(H,X,LABEL,LABELNUMBERS)
[Y,FLAG] = step(H,X,ROI)
[Y,FLAG] = step(H,X,LABEL,LABELNUMBERS)

Description

Y = step(H,X) computes the variance of input X. When you set the RunningVariance property to true, the output Y corresponds to the standard deviation of the input elements over successive calls to the step method.

Y = step(H,X,R) computes the variance of the input elements X over successive calls to the step method, and optionally resets its state based on the value of the reset signal R, the ResetInputPort property and the ResetCondition property. This option applies when you set the RunningVariance property to true and the ResetInputPort to true.

Y = step(H,X,ROI) computes the variance of input image X within the given region of interest ROI when you set the ROIProcessing property to true and the ROIForm property to Lines, Rectangles or Binary mask.

Y = step(H,X,LABEL,LABELNUMBERS) computes the variance of input image X for region labels contained in vector LABELNUMBERS, with matrix LABEL marking pixels of different regions. This option applies when you set the ROIProcessing property to true and the ROIForm property to Label matrix.

[Y,FLAG] = step(H,X,ROI) also returns the output FLAG, which indicates whether the given region of interest is within the image bounds. This applies when you set both the ROIProcessing and the ValidityOutputPort properties to true and the ROIForm property to Lines, Rectangles or Binary mask.

[Y,FLAG] = step(H,X,LABEL,LABELNUMBERS) also returns the FLAG, which indicates whether the input label numbers are valid. This applies when you set both the ROIProcessing and ValidityOutputPort properties to true and the ROIForm property to Label matrix.

    Note:   H specifies the System object™ on which to run this step method.

    The object performs an initialization the first time the step method is executed. This initialization locks nontunable properties and input specifications, such as dimensions, complexity, and data type of the input data. If you change a nontunable property or an input specification, the System object issues an error. To change nontunable properties or inputs, you must first call the release method to unlock the object.

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