InfoHasAlpha example for Delphi
LEAD1.Load ('c:\temp\1.jpg', 24, 1, 1);// load a 24-bit image
LEAD2.Bitmap := LEAD1.Bitmap;
LEAD2.ColorRes(8, 0, 0, 0);// just make it 8-bit
//now set an alpha channel
LEAD1.BitmapAlpha := LEAD2.Bitmap;
//save and free
LEAD1.Save ('c:\temp\32.png', FILE_PNG, 32, 0, 0);
LEAD1.Bitmap := 0;
LEAD2.Bitmap := 0;
Application.MessageBox ('Pause','Pause',0);
//re-load
LEAD1.GetFileInfo ('c:\temp\32.png', 0);
If (LEAD1.InfoHasAlpha <> False) Then
LEAD1.Load ('c:\temp\32.png', 0, 1, 1);
LEAD2.Bitmap := LEAD1.BitmapAlpha;