Description
Adds an alpha channel to an image.
Syntax
| Visual Basic |
|---|
Public Sub AlphaAdd( _ ByVal hDIB As Long _ ) |
Parameters
- hDIB
- A handle to a device independent bitmap containing the alpha channel data to add to the image.
Remarks
Adds a user supplied 8 bit alpha channel to an existing 24 bit image, thus promoting the image to 32 bits. The current image (ProcessImageID) is now a 32 bit image, containing alpha channel.
The Image at hDIB should be the same width and height of the image it is being added to. The Image Bitmap must be an 8 bit gray scale type with a uniform grayscale palette.
If the original image is not 24-bit then an exception is thrown.