ROI Filter

The ROI filter cuts a region of interest out of the incoming frames. It creates a new output video format.

Using the ROI Filter

The ROI filter is loaded by an application using following code:

Dim ROIFilter As FrameFilter
Set ROIFilter = ICImagingControl1.FrameFilterCreateString("ROI", "stdfilters.ftf")

Parameters

The part of the image that is copied to the destination frame is determined by four filter parameters:

Left

This value specifies the left column on the source frame at which the region of interest (ROI) starts. This value is used to move the region of interest horizontally to the source frame. It can be changed regardless of whether the live video is running or not.

Top

This value specifies the top row on the source frame at which the region of interest starts. This value is used to move the region of interest vertically to the source frame. It can be changed regardless of whether the live video is running or not.

Width

This value specifies the width of the region of interest. It can only be set while the live video is stopped. Otherwise, the resulting video format would be changed.

Height

This value specifies the height of the region of interest. It can only be set while the live video is stopped. Otherwise, the resulting video format would be changed.

Property Dialog

The dimensions and the start positions of the region of interest can be specified in the ROI filter's property dialog:

Programmatically Access the Parameter

The following source code can be used, if the parameter should be set by an application:

Dim left As Long
Dim top As Long
Dim height As Long
Dim width As Long
 
' Retrieve the current ROI rectangle.
left = ROIFilter.Parameter("Left")
top = ROIFilter.Parameter("Top")
height = ROIFilter.Parameter("Height")
width = ROIFilter.Parameter("Width")
 
' Set a new ROI.
left = 100
top = 50
' The position of the ROI can be set regardless of whether the live video is running
' because the size of the resulting video format is not changed.
ROIFilter.Parameter("Left") = left
ROIFilter.Parameter("Top") = top
 
If Not ICImagingControl1.LiveVideoRunning Then
    ' A new ROI width and height can only be set, while the live video ist stopped.
    ' Otherwise, an error is returned by setParameter().
    height = 120
    width = 180
    ROIFilter.Parameter("Height") = height
    ROIFilter.Parameter("Width") = width
End If

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