Sahding an Image to a color - [Solved]

[zxandris]

I have a project where I would like to shade an existing image a certain color.  Not replace colors, but shade if you see what I mean.  I currently don't have a clue on this one, if anyone would be willing to help I would be grateful.  In theory i go through the pixels and add with a certain tolerance, right?  But I am completely unsure how to actually go about this.

They would likely be quite small images, up to about 256 so I would imagine something like the old scanline might help?  Theory would help a great deal, and examples would be awesome

CJ

[Dzandaa]

Hi,

Something like this?

B->

[zxandris]

Yes, that's just the job, mate! I just tweaked it a tiny bit to preserve the alpha channel. For the purposes of my little app, I also made it into a function

Thank you so much!

Code: Pascal  [Select][+][-]

1. function BgraColorise(var pictOrig : TBgraBitmap; const clrBlend : TColor; const boolBW : Boolean) : TBgraBitmap;
2. var
3.         Pxo, Pxd: PBGRAPixel;
4.         CSelect: TBGRAPixel;
5.         ColBW: Integer;
6.         i: integer;
7.         PictDest : TBgraBitmap;
8. begin
9.      CSelect := ColorToBgra(clrBlend);
10.      if(PictOrig = nil) then exit;
11.      if(PictDest <> nil) then FreeAndNil(PictDest);
12.      PictDest := TBGRABitmap.Create(PictOrig.Width, PictOrig.Height, BGRABlack);
13.      Pxo := PictOrig.Data;
14.      Pxd := PictDest.Data;
15.      for i := PictOrig.NbPixels-1 downto 0 do
16.      begin
17.                         if(boolBW) then
18.                         begin
19.                              ColBW := Round(0.299 * Pxo^.red + 0.587 * Pxo^.green + 0.114 * Pxo^.blue);
20.                              Pxd^.red := Round((ColBW + CSelect.red) / 2.0);
21.                              Pxd^.green := Round((ColBW + CSelect.green) / 2.0);
22.                              Pxd^.blue := Round((ColBW + CSelect.blue) / 2.0);
23.                              pxd^.alpha := pxo^.alpha;
24.                         end else
25.                         begin
26.                              Pxd^.red := Round((Pxo^.red + CSelect.red) / 2.0);
27.                              Pxd^.green := Round((Pxo^.green + CSelect.green) / 2.0);
28.                              Pxd^.blue := Round((Pxo^.blue + CSelect.blue) / 2.0);
29.                              pxd^.alpha := pxo^.alpha;
30.                         end;
31.                         inc(Pxo);
32.                         inc(Pxd);
33.      end;
34.      result := pictDest;
35. end;
36.  

Hi,

Something like this?

B->