Convert BGRAbitmap to 256 Color BMP and save

[winni]

Hi!

Question in the german forum:

How to convert BGRAbitmap to a 256 Color BMP and save it?

It is needed by some SAP software that rejects all images except 256-Color-BMP.

Is there a solution yet?  I have not found anything.

Winni

[paweld]

Hi,
sample code:

Code: Pascal  [Select][+][-]

1. uses  
2.   BGRABitmap, BGRABitmapTypes, BGRAColorQuantization, FPWriteBmp;
3.  
4.  
5. procedure TForm1.Button1Click(Sender: TObject);
6. var
7.   img: TBGRABitmap;
8.   bmpw: TFPWriterBmp;
9.   quant: TBGRAColorQuantizer;
10.   i: Integer;
11. begin
12.   img := TBGRABitmap.Create('d:\wzor80.jpg');
13.   bmpw := TFPWriterBmp.Create;
14.   bmpw.BitsPerPixel := 8;
15.   //bmpw.RLECompress := True;
16.  
17.   quant := TBGRAColorQuantizer.Create(img, acIgnore, 256);  //reduce color to 256 without alfa
18.   quant.ApplyDitheringInplace(daNearestNeighbor, img);
19.   img.UsePalette := True;
20.  
21.   img.Palette.Clear;
22.   for i := 0 to quant.ReducedPalette.Count - 1 do      //copy reduced colors to palette
23.     img.Palette.Add(quant.ReducedPalette.Color[i].ToFPColor);
24.  
25.   img.SaveToFile('d:\wzor80_256color.bmp', bmpw);   //save as bmp
26.   bmpw.Free;     //clean
27.   img.Free;
28.   quant.Free;
29. end;        
30.  

[winni]

Hi!

Thanx a lot.

The Quantizer was the part that I forgot. Getting old ...

The Link in the german forum:

https://www.lazarusforum.de/viewtopic.php?f=18&t=14593&p=131460#p131460


Winni