Working with the Existing Region

You can save a region in the alpha channel of a 16- or 32-bit file. For an example, refer to RasterImage.SetAlphaImage.

You can check the RasterImage.HasRegion property to see if an image has a region. If the image has a region, you can do the following with it:

Use RasterImagePainter.FrameRegion to outline the region.
Use RasterImageConverter.GetGdiRegionData to create a Windows region that is a snapshot of the region.
Use RasterImage.OffsetRegion to move the region.
Use RasterImage.CalculateRegionArea, RasterImage.GetRegionBounds, and RegionContains to get information about the region's size and location.
Use RasterImage.AddColorToRegion to display a filled, color representation of a region.
Use RasterImage.MakeRegionEmpty to free the region.
Determine the number of maximum number of segments present in any row in the region by calling RasterImage.CalculateRegionMaximumClipSegments Once this is known, a buffer can be allocated and the segments can be retrieved using the RasterImage.GetRegionClipSegments method.

To create a new region, or update an existing region, based on either an HSV range or an RGB range, use RasterImage.AddColorHsvRangeToRegion or RasterImage.AddColorRgbRangeToRegion. To convert between HSV and RGB color space, use the RasterHsvColor class and the RasterHsvColor.ToRasterColor method.

To create a new curve region, or update an existing region with a curve region, use ResizeRegionCommand class.

Use the RegionHolesRemovalCommand class to remove holes from a region.

Regions are saved automatically inside TIFF files. For more information, refer to Saving a Region. Note, however, that the ability to save a region inside a TIFF file must be unlocked. This requires a Document Imaging or Medical Imaging toolkit.