SetFrameCaptureBounds

TVideoGrabber.SetFrameCaptureBounds

Specifies a frame capture rectangle

Declaration
procedure SetFrameCaptureBounds (LeftPosition: LongInt; TopPosition: LongInt; RightPosition: LongInt; BottomPosition: LongInt);

void __fastcall SetFrameCaptureBounds(int LeftPosition, int TopPosition, int RightPosition, int BottomPosition

Sub SetFrameCaptureBounds (LeftPosition as Long, TopPosition as Long, RightPosition as Long, BottomPosition as Long)

Description

Used to capture a sub-rectangle of the video frame

Used to specify a rectangle for the frame capture, allowing to capture only parts of the video frame.

E.g.:

Button1 action:
VideoGrabber.StartPreview()

Button2 action:
VideoGrabber.SetFrameCaptureBounds (50, 50, 150, 150)
VideoGrabber.CaptureFrameTo (fc_JPEGFile, "mysquarecapture.jpg")

When starting the preview with Button1, then capturing a frame with Button2, the captured frame will be a square 100x100 image captured at the "x=50 y=50" location on the video frame.

Note: rhe normal full frame capture can then be restored by invoking SetFrameCaptureBounds (0, 0, 0, 0)

Top-down or left-right capture

Additionally it is possible top-down or left-right the captured frame by just inverting the Left/Right or Top/Bottom values.

E.g.:
VideoGrabber.SetFrameCaptureBounds (50, 150, 150, 50) will capture a top-down frame.

Remark: to retrieve the current size of the video frame use VideoWidth and VideoHeight