Converts any indexed format to any ARGB format.

procedure IndexToChannel(NumPixels: LongInt; 
                         Src: PByte; 
                         Dst: PByte; 
                         SrcInfo: PImageFormatInfo; 
                         DstInfo: PImageFormatInfo; 
                         SrcPal: PPalette32);

ImagingFormats (at line 294)