# Region

Use the Region tab to limit the operation of the pixel map tool to a region of the input image. If you specify a value other than None - Use Entire Image, the output image will be sized to the pixel-aligned bounding rectangle of the region that you specify.

Parameter | Description
--- | ---
Region Shape | Select the shape of the input region. Selecting None=Use entire image means that the tool uses the entire input image. A Blob tool supports the following input region shapes: Circle Ellipse Polygon Rectangle RectangleAffine CircularAnnulusSection EllipitcalAnnulusSection The set of region-defining parameters that appear depend on the region shape you use.
Selected Space Name | The coordinate space in which the region is interpreted.
Select Mode | Available when Rectangle or RectangleAffine is the chosen Region Shape. Selects the set of parameters to use to define the rectangle. If RectangleAffine is chosen, note that the angle of rotation and skew can be specified in degrees or radians, although the underlying tool keeps the measurements in radians.
Fit In Image | Centers the region of interest within the image. Adjust the shape's geometric properties so that its default size is based on the image and its Selected Space Name.
Only Use Region to Compute Ref | When checked (it is unchecked by default), reference points are computed using the contents of the region, and the mapping is applied to the whole image. The size of the output image is the same as the size of the input image. When unchecked, the reference points are computed using the content of the region, and the size of the output image is the same as the size of the region. If the Region is set to None=Use entire image this property is ignored.