FAQ: Working with a Region

How does a region affect RasterImages?
By default, LEADTOOLS RasterCommands function on a RasterImage as a whole. However, there are specific RasterCommands which only operate on a defined region of an image if such a region exists. These commands our listed in our documentation.
https://www.leadtools.com/help/sdk/dh/to/region-processing-functions-where-the-region-preempts-the-image.html

Also note some commands disregard the presence of a region and are applied to the entire image regardless.
[url=https://www.leadtools.com/help/sdk/dh/to/commands-and-methods-that-transform-the-region-and-the-image.htmlhttps://www.leadtools.co...egion-and-the-image.html[/url]

How can a region be added to a RasterImage?
We offer a wide variety of methods to add a region to an image. Rectangles, polygons, ellipses, all pixels of a specific color can all be used to add a region. See our documentation for a complete list.
https://www.leadtools.com/help/sdk/dh/to/defining-and-using-a-region.html

How can a region be defined?
There are multiple ways in which the area of a region can be manipulated. It's not necessary for a region to be a consistent shape, size, nor be in one piece or contiguous. For information on how regions can be defined see our documentation on "Creating a Region", which shows the various methods in which region boundaries can be manipulated.
https://www.leadtools.com/help/sdk/dh/to/creating-a-region.html

Can region definitions persist in saved files?
Files saved in the TIFF file format will have their regions saved. However, it's necessary to have licensed either Document Imaging or Medical Imaging to access this functionality.
https://www.leadtools.com/help/sdk/dh/to/saving-a-region.html

How can it be determined if a RasterImage has a region defined?
The RasterImage.HasRegion property contains a boolean value that determines if a region of any area is present in the image.
https://www.leadtools.com/help/sdk/dh/l/rasterimage-hasregion.html

Can a region be removed?
The RasterImage.MakeRegionEmpty() method removes an existing region from an image. Note this removes the entire region regardless of area--even if there are multiple non-contiguous areas of interest in an image, these are still considered to be a single region.
https://www.leadtools.com/help/sdk/dh/l/rasterimage-makeregionempty.html

Edited by moderator Wednesday, December 27, 2023 1:59:06 PM(UTC)  | Reason: Updated