04-11-2012, 02:42 PM
scan ignores alpha channel of bmp. It is rarely used with bmp, and would create more problems than be useful.
How scan works with alpha icons? It creates mask from all alpha pixels of the icon, ie from pixels where alpha is not 255 (255 is completely opaque). Then, when searching, does not compare these pixels with screen pixels. Similarly, if used bmp and flag 4, it creates mask from all pixels of the image that match color of top-left pixel.
It means that you don't need to add alpha channel to bmp images. But you can create mask manually. Open the image in mspaint or other editor and draw mask with color of top-left pixel. Then use flag 4 with scan. All mask pixels will not be compared with screen pixels when searching.
How scan works with alpha icons? It creates mask from all alpha pixels of the icon, ie from pixels where alpha is not 255 (255 is completely opaque). Then, when searching, does not compare these pixels with screen pixels. Similarly, if used bmp and flag 4, it creates mask from all pixels of the image that match color of top-left pixel.
It means that you don't need to add alpha channel to bmp images. But you can create mask manually. Open the image in mspaint or other editor and draw mask with color of top-left pixel. Then use flag 4 with scan. All mask pixels will not be compared with screen pixels when searching.