unit filterArithmeticSubstract;
(* ***** BEGIN LICENSE BLOCK *****
 * Copyright (C) 2004 Durand Emmanuel
 * Copyright (C) 2004 Burgel Eric
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Contact :
 *   filters@edurand.com
 *   filters@burgel.com
 *
 * ***** END LICENSE BLOCK ***** *)

{
 edurand (filters@edurand.com)
}

interface
uses
  filter, fparameters, image;

type
  TfilterArithmeticSubstract = class(TFilter)
  public
    constructor Create; override;
    procedure Run(); override;
  private
    parameterImageIn1, parameterImageIn2, parameterImageOut : TParameterImage;
    parameterMode : TParameterString;
    ouputParameterDeltaTotal : TParameterInteger;
    normalizedDeltaTotal : Integer;
    procedure _run(); 
  end;

implementation
uses
  Math;

constructor TfilterArithmeticSubstract.Create;
begin
  inherited;
  parameterImageIn1:=addParameterImage('inImage1','input image 1');
  parameterImageIn2:=addParameterImage('inImage2','input image 2');
  parameterImageOut:=addParameterImage('outImage','see mode parameter');
  parameterMode:=addParameterString('mode','SUBSTRACT(inImage1-inImage2) or DIFFERENCE(abs(inImage1-inImage2))','DIFFERENCE');
  ouputParameterDeltaTotal := addOutputParameterInteger('normalizedDeltaTotal', 'somme of all substract or difference, divide by total pixels number') ;
end;

procedure TfilterArithmeticSubstract.Run();
begin
  if (parameterImageIn1.Image<>nil) and (parameterImageIn2.Image<>nil) and (parameterImageOut.Image<>nil) then begin
    _run();
  end;
end;

procedure TfilterArithmeticSubstract._run();
var
  pSrc1, pSrc2, PDest : PColor32Array;
  w,h :Integer;
  x, max : Cardinal ;
  color1, color2 : TColor32;
  intensity, intensity1, intensity2 : Integer;
  bModeDifference : boolean;
  fnormalizedDeltaTotal : Single;
begin
  pSrc1:=parameterImageIn1.Image.Bits;
  pSrc2:=parameterImageIn2.Image.Bits;
  pDest:=parameterImageOut.Image.Bits;
  h:=parameterImageIn1.Image.Height;
  w:=parameterImageIn1.Image.Width;
  normalizedDeltaTotal:=0;
  fnormalizedDeltaTotal:=0;

  bModeDifference:=true;
  if(parameterMode.Value<>'DIFFERENCE') then begin
    bModeDifference:=false;
  end;

  max := h*w-1 ;
 // B/W
  for x:= 0 to max do Begin
    color1:=pSrc1^[0];
    color2:=pSrc2^[0];

    intensity1:=image.Intensity(color1);
    intensity2:=image.Intensity(color2);
    intensity:=intensity1-intensity2;

    if bModeDifference=true then begin
      intensity:=abs(intensity);
    end else begin
      if intensity<0 then intensity:=0;
    end;
    fnormalizedDeltaTotal:=fnormalizedDeltaTotal + intensity / max;

    pDest[0]:=Color32(intensity,intensity,intensity);

    inc(pSrc1);
    inc(pSrc2);
    inc(pDest);
  end ;

{ // Color
  for x:= 0 to max do Begin
    color1:=pSrc1^[0];
    color2:=pSrc2^[0];

    r:=RedComponent(color1)-RedComponent(color2);
    if r<0 then r:=0;

    g:=GreenComponent(color1)-GreenComponent(color2);
    if g<0 then g:=0;

    b:=BlueComponent(color1)-BlueComponent(color2);
    if b<0 then b:=0;

    pDest[0]:=Color32(r,g,b);

    inc(pSrc1);
    inc(pSrc2);
    inc(pDest);
  end ;
}
  normalizedDeltaTotal:=Floor(fnormalizedDeltaTotal);
  setOutputParameterInteger('normalizedDeltaTotal', normalizedDeltaTotal);
end;

end.