System object: visionhdl.ROISelector
Package: visionhdl
Return next pixel in reselected frame
[pixel1,ctrl1] = step(ROI,pixelIn,ctrlIn)
[pixel1,ctrl1,...,pixelN,ctrlN] = step(ROI,pixelIn,ctrlIn)
[pixel1,ctrl1,...,pixelN,ctrlN] = step(ROI,pixelIn,ctrlIn,region1,...,regionN)
Starting in R2016b, instead of using the step method
to perform the operation defined by the System
object™, you can
call the object with arguments, as if it were a function. For example, y
= step(obj,x) and y = obj(x) perform
equivalent operations.
[pixel1,ctrl1] = step(ROI,pixelIn,ctrlIn) returns
the next pixel value, pixel1, and control signals, ctrl1,
resulting from masking the active image frame into a single new region.
Define the region by setting the Regions property
to a 1-by-4 vector, [hPos vPos hSize vSize].
[pixel1,ctrl1,...,pixelN,ctrlN] = step(ROI,pixelIn,ctrlIn) returns
the next pixel values, pixel1,...,pixelN, and
control signals, ctrl1,...,ctrlN, of each stream
resulting from masking the active image frame into 1 to N new
active regions, as directed by the Regions property.
Set the Regions property to a N-by-4
matrix of region coordinates.
[pixel1,ctrl1,...,pixelN,ctrlN] = step(ROI,pixelIn,ctrlIn,region1,...,regionN) returns
the next pixel values of each stream, pixel1,...,pixelN,
resulting from masking the active image frame into 1 to N new
regions, as directed by the region1,...,regionN arguments.
Each region input is a 1-by-4 vector of region
coordinates. Use this syntax when you set the RegionsSource property
to 'Input Port', and the NumberOfRegions property
to N.
This object uses a streaming pixel interface with a structure
for frame control signals. This interface enables the object to operate independently of image
size and format, and to connect with other Vision HDL
Toolbox™ objects. The object accepts and returns a scalar pixel value. The object accepts
and returns control signals as a structure containing five signals. The control signals indicate
the validity of each pixel and its location in the frame. To convert a pixel matrix into a pixel
stream and control signals, use the visionhdl.FrameToPixels object. For a full
description of the interface, see Streaming Pixel Interface.
The object performs an initialization the first time you call
the step method. 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, first call the release method
to unlock the object.