I see pleny of examples of how to convert a 24 bit color bitmap to
grayscale, but not a 1-bit b&w to grayscale.....

Can anyone provide me with an actual example of how to accomplish this?
--
Brent Hampton

You intend to create information that was not there before.
I'd start with 0 -> 0(black) and 1 -> 255(white)
then you could do a lowpass filter that smears a bit.

Rene
--
Ing.Buero R.Tschaggelar - http://www.ibrtses.com

Grayscale (8 bit) stores more information than b&w (1 bit), so it should
be pretty easy to convert it (the difficult part is to reduce the
information, which is not needed in this case). Do you need a fast
scanline algorithm? It would be something like...

var
  BWPointer: ^Byte;
  GrayPointer: ^Byte;
  x,y: Integer;
  BitNumber,BitValue: Byte;
begin
  for y := 0 to Height-1 do begin
    BWPointer := BWBitmap.ScanLine[y];
    GrayPointer := GrayBitmap.ScanLine[y];
    for x := 0 to Width-1 do begin
      BitNumber := x AND 7; // or maybe 7-(x AND 7) ???
      BitValue := BWPointer^ SHR (BitNumber) AND 1;
      GrayPointer^ := BitValue*255; // or more general: a+BitValue*b;
      Inc (GrayPointer);
      if (x AND 7) = 7 then Inc (BWPointer);
    end;
  end;
end;

This code was not tested and can probably be enhanced (for example by
using a 32 bit BWPointer).

Jens

Thanks!

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