step

System object: vision.EdgeDetector
Package: vision

Find edges in input image

Syntax

EDGES = step(H,IMG)
[GV,GH] = step(H,IMG)
[EDGES,GV,GH] = step(H,IMG)

Description

EDGES = step(H,IMG) finds the edges, EDGES , in input IMG using the specified algorithm when the BinaryImageOutputPort property is true. EDGES is a boolean matrix with non-zero elements representing edge pixels and zero elements representing background pixels.

[GV,GH] = step(H,IMG) finds the two gradient components, GV and GH , of the input IMG, when you set the Method property to Sobel, Prewitt or Roberts, and you set the GradientComponentOutputPorts property to true and the BinaryImageOutputPort property to false. If you set the Method property to Sobel or Prewitt, then GV is a matrix of gradient values in the vertical direction and GH is a matrix of gradient values in the horizontal direction. If you set the Method property to Roberts, then GV represents the gradient component at 45 degree edge response, and GH represents the gradient component at 135 degree edge response.

[EDGES,GV,GH] = step(H,IMG) finds the edges, EDGES , and the two gradient components, GV and GH , of the input IMG when you set the Method property to Sobel, Prewitt or Roberts and both the BinaryImageOutputPort and GradientComponentOutputPorts properties are true.

    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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