//Histogram - rozciąganie histogramu
//(c) 2005 Tomasz Lubinski
//www.algorytm.org

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  OleCtrls, chartfx3, jpeg, ExtCtrls, StdCtrls, TeeProcs, TeEngine, Chart,
  Series, ComCtrls;

type
  LUTType = Array[0..255] of Double;

  TForm1 = class(TForm)
    Button1: TButton;
    ObrazKolorowy: TImage;
    Histogram1: TChart;
    Series1: TLineSeries;
    Series2: TLineSeries;
    Series3: TLineSeries;
    ObrazMono: TImage;
    Histogram2: TChart;
    LineSeries1: TLineSeries;
    Chart3: TChart;
    LineSeries2: TLineSeries;
    WynikKolorowy: TImage;
    WynikMono: TImage;
    Series4: TLineSeries;
    Series5: TLineSeries;
    Series6: TLineSeries;
    procedure Button1Click(Sender: TObject);
    procedure UpdateLUT(a: double; b: integer; var LUT: LUTType; series: Integer);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  LUTr, LUTg, LUTb, LUTgray: LUTType;

implementation

{$R *.DFM}

procedure TForm1.Button1Click(Sender: TObject);
var
    i, j, rvalue, gvalue, bvalue, grayvalue: Integer;
    rmin, gmin, bmin, graymin, rmax, gmax, bmax, graymax: Integer;
    r, g, b, gray: Array [0..255] of Double;
    color: TColor;
begin
for i := 0 to 255 do
    begin
        r[i] := 0;
        g[i] := 0;
        b[i] := 0;
        gray[i] := 0;
    end;

//znajdz minimum i maksimum kazdej skladowej
rmin := 255;
gmin := 255;
bmin := 255;
graymin := 255;
rmax := 1;
gmax := 1;
bmax := 1;
graymax := 1;
for i := 0 to ObrazKolorowy.Width-1 do
    for j := 0 to ObrazKolorowy.Height-1 do
        begin
            color := ObrazKolorowy.Canvas.Pixels[i,j];
            rvalue := GetRValue(color);
            gvalue := GetGValue(color);
            bvalue := GetBValue(color);
            if rvalue > rmax then rmax := rvalue;
            if gvalue > gmax then gmax := gvalue;
            if bvalue > bmax then bmax := bvalue;
            if rvalue < rmin then rmin := rvalue;
            if gvalue < gmin then gmin := gvalue;
            if bvalue < bmin then bmin := bvalue;
        end;
for i := 0 to ObrazMono.Width-1 do
    for j := 0 to ObrazMono.Height-1 do
        begin
            color := ObrazMono.Canvas.Pixels[i,j];
            grayvalue := GetRValue(color);
            if grayvalue > graymax then graymax := grayvalue;
            if grayvalue < graymin then graymin := grayvalue;
        end;

//przelicz tablice LUT, tak by rozciagnac histogram
updateLUT(255/(rmax-rmin), -rmin, LUTr, 1);
updateLUT(255/(gmax-gmin), -gmin, LUTg, 2);
updateLUT(255/(bmax-bmin), -bmin, LUTb, 3);
updateLUT(255/(graymax-graymin), -graymin, LUTgray, 0);

for i := 0 to ObrazKolorowy.Width-1 do
    for j := 0 to ObrazKolorowy.Height-1 do
        begin
            color := ObrazKolorowy.Canvas.Pixels[i,j];
            rvalue := GetRValue(color);
            gvalue := GetGValue(color);
            bvalue := GetBValue(color);
            //zmien wartosc wedlug tablicy LUT
            color := Round(LUTr[rvalue]) +
                    (Round(LUTg[gvalue]) shl 8) +
                    (Round(LUTb[bvalue]) shl 16);
            //oblicz histogram
            WynikKolorowy.Canvas.Pixels[i,j] := color;
            r[GetRValue(color)] := r[GetRValue(color)] + 1;
            g[GetGValue(color)] := g[GetGValue(color)] + 1;
            b[GetBValue(color)] := b[GetBValue(color)] + 1;
        end;
Histogram1.SeriesList.Series[0].Clear;
Histogram1.SeriesList.Series[1].Clear;
Histogram1.SeriesList.Series[2].Clear;
Histogram1.SeriesList.Series[0].AddArray(r);
Histogram1.SeriesList.Series[1].AddArray(g);
Histogram1.SeriesList.Series[2].AddArray(b);

for i := 0 to ObrazMono.Width-1 do
    for j := 0 to ObrazMono.Height-1 do
        begin
            color := ObrazMono.Canvas.Pixels[i,j];
            grayvalue := GetRValue(color);
            //zmien wartosc wedlug tablicy LUT
            color := Round(LUTgray[grayvalue]) +
                    (Round(LUTgray[grayvalue]) shl 8) +
                    (Round(LUTgray[grayvalue]) shl 16);
            //oblicz histogram
            WynikMono.Canvas.Pixels[i,j] := color;
            gray[GetRValue(color)] := gray[GetRValue(color)] + 1;
        end;
Histogram2.SeriesList.Series[0].Clear;
Histogram2.SeriesList.Series[0].AddArray(gray);
end;

//zmień wartosc jasnosci i kontrastu
//przelicz nowe wartosci tablicy LUT
//wyswietl wartosci tablicy LUT
procedure TForm1.UpdateLUT(a: double; b: integer; var LUT: LUTType; series: Integer);
var
    i: Integer;
begin
for i := 0 to 255 do
    if (a*(i+b)) > 255 then
        LUT[i] := 255
    else if (a*(i+b)) < 0 then
        LUT[i] := 0
    else
        LUT[i] := (a*(i+b));
Chart3.SeriesList.Series[series].Clear;
Chart3.SeriesList.Series[series].AddArray(LUT);
end;


end.