Image Cropping

The image cropping operator - ICO - selects a subset of the pixels delivered by the camera to build the image delivered to the Host PC; this subset is named Window Area:
  • For area-scan cameras, the Window Area is a single rectangular region of the 2D image sensor.
  • For line-scan cameras, the Window Area is a single segment of the 1D image sensor.

ICO parameters

The ICO is controlled through the following Channel Class parameters of the Grabber Timing category:
  • GrabWindow: the main control parameter.
  • WindowX_Px, WindowY_Ln: integer parameters defining the size of the Window Area.
  • OffsetX_Px, and OffsetY_Ln: integer parameters defining the position of the Window Area within the Camera Active Area.

Figure: Window Area Parameters for Area-Scan cameras

Figure: Window Area Parameters for Line-Scan cameras

Note: The position of the Window Area within the Camera Active Window is expressed as the difference of coordinates between Cw, the center of the Window Area, and Cw, the center of the Camera Active Area.
Note: The range of allowed values of OffsetX_Px and OffsetY_Ln parameters is automatically adjusted to force the Window Area to stay within the boundaries of the Camera Active Area.
Note: WindowOrgX_Px reports the X-coordinate in the Camera Active Area of the leftmost pixels of the Window Area: WindowOrgX_Px = (Hactive_Px - WindowX_Px) / 2
Note: For area-scan cameras only: WindowOrgY_Ln reports the Y-coordinate in the Camera Active Area of the topmost pixels of the Window Area: WindowOrgY_Ln = (Vactive_Ln - WindowY_Ln) / 2

Configuring the Image Cropping Operator

By default, GrabWindow is set to NOBLACK disabling the ICO: the acquired image includes all active pixels delivered by the camera without any surrounding weak or blind pixels on the image edges.

To enable image cropping, proceed as follows:
  • Enable ICO by setting GrabWindow to MAN.
  • Adjust the width of the Window Area using WindowX_Px. Any integer value ranging from 8 up to Hactive_Px is allowed.
  • For area-scan cameras only: Adjust the height of the Window Area using WindowY_Ln. Any integer value ranging from 1 up to Vactive_Ln is allowed.
  • Move horizontally the Window Area using OffsetX_Px. Increasing the value moves the Window Area towards the right of the Camera Active Area and vice-versa, decreasing the value moves the Window Area towards the left of the Camera Active Area.
  • For area-scan cameras only:Move vertically the Window Area using OffsetY_Ln. Increasing the value moves the Window Area towards the top of the Camera Active Area and vice-versa, decreasing the value moves the Window Area towards the bottom of the Camera Active Area.

Conditions of applicability

ICO is applicable to the following camera classes:
  • Monochrome, RGB color, and Bayer CFA color area-scan cameras: any valid combination of TapConfiguration and TapGeometry is allowed except whenTapGeometry = *_2YE
  • Monochrome, and RGB color line-scan cameras.