How to apply color profiles to produce real color?

[WojTec]

Ok, but should be here:

{ Input }, { Output } cmsDoTransform() is waiting for pointer to bitmap, if I see well in manual, I don't understand how to use it for simple color?

[freeway]

create a 1x1 bitmap
set this pixel to a single color

[WojTec]

Ok, I did it with 1x1 bitmap and finally I got this:

Delphi-Quellcode:

function CreateBitmap: TBitmap;
begin
  Result := TBitmap.Create;
  Result.SetSize(1, 1);
end;

function SingleColor(const AColor: TColor): TBitmap;
begin
  Result := CreateBitmap;
  Result.Canvas.Pixels[0, 0] := AColor;
end;

function GetColor(const ABitmap: TBitmap): TColor;
begin
  Result := ABitmap.Canvas.Pixels[0, 0];
end;

var
  SrcProfile, DstProfile: string;
  hSrc, hDest: cmsHPROFILE;
  Transform: cmsHTRANSFORM;
  Intent: Integer;
  dwFlags: DWORD;
  InColor, OutColor: TBitmap;
begin
  SrcProfile := TICCProfileItem(cbRGBProfiles.Items.Objects[cbRGBProfiles.ItemIndex]).Path;
  DstProfile := TICCProfileItem(cbCMYKProfiles.Items.Objects[cbCMYKProfiles.ItemIndex]).Path;

  if cbCompensation.Checked then
    dwFlags := cmsFLAGS_BLACKPOINTCOMPENSATION
  else
    dwFlags := 0
  ;

  Intent := IntentCodes[cbIntents.ItemIndex];

  //cmsSetAdaptationState(cmsSetAdaptationState(-1));

  if (SrcProfile <> '') and (DstProfile <> '') then
  begin
    hSrc := cmsOpenProfileFromFile(PAnsiChar(AnsiString(SrcProfile)), 'r');
    hDest := cmsOpenProfileFromFile(PAnsiChar(AnsiString(DstProfile)), 'r');

    if (hSrc <> nil) and (hDest <> nil) then
      Transform := cmsCreateTransform(hSrc, TYPE_BGR_8, hDest, TYPE_BGR_8,
        Intent, dwFlags)
    else
      Transform := nil
    ;

    if hSrc <> nil then
      cmsCloseProfile(hSrc);
    ;
    if hDest <> nil then
      cmsCloseProfile(hDest);
    ;

    InColor := SingleColor(RGB(255, 0, 0));
    OutColor := CreateBitmap;
    OutColor.Assign(InColor);

    if (Transform <> nil) then
    try
      cmsDoTransform(Transform, InColor.Scanline[0], OutColor.Scanline[0], 1);
    finally
      cmsDeleteTransform(Transform);
    end;

    Color := SingleColor(OutColor);
  end
end;

So, this should convert RGB to CMYK (here monitor RGB to paint CMYK) - I selected from list sRGB IEC6 1966-2.1 for RGB and US Web Coated (SWOP) v2 for CMYK. I expect CMYK red, but I got RGB red (same as input). What I'm doing wrong?

[freeway]

you create OutColor := CreateBitmap but where did you create Incolor ?

PS don´t forgot to release your created bitmaps