//...

type
  TXYValues = class
  Values: array of array of byte;
  LeftX, LeftY: Integer;
   private
    procedure RegionGrowing(x,y,i: integer; var image: TImage);
   public
    constructor Create(LengthX, LengthY: Integer);
    function NoRegionLeft(i: integer): boolean;
    function IsAenlich(maxunterschied:Integer; var c1,c2:tcolor):boolean;
    procedure StartRegionGrowing(image: TImage; i: integer);
  end;

//...

procedure TXYValues.RegionGrowing(x,y,i: integer; var image: TImage);
var c, c1, c2, c3, c4: TColor;
begin
c := image.Canvas.Pixels[x,y];
c1 := image.canvas.pixels[x+1,y];
c2 := image.Canvas.Pixels[x-1,y];
c3 := image.canvas.pixels[x,y-1];
c4 := image.canvas.pixels[x,y+1];

if form1.progressbar1.position = form1.progressbar1.max then
form1.progressbar1.position := 0;
form1.progressbar1.Position := form1.progressbar1.Position+1;

if (High(values) >= x) and (x >= 0) then
 if (high(values[x]) >= y) and (y >= 0) then
 begin

 if high(values) > x then
 if (values[x+1][y]=0) then
  if (IsAenlich(50, c, c1)) then
   begin
   values[x+1][y] := i;
   RegionGrowing(x+1,y,i,image);
   end;

 if x > 0 then
  begin
 if (values[x-1][y]=0) then
  if (IsAenlich(50, c, c2)) then
   begin
   values[x-1][y] := i;
   RegionGrowing(x-1,y,i,image);
   end;
 end;

 if y > 0 then
 begin
 if (values[x][y-1]=0) then
  if (IsAenlich(50, c, c3)) then
   begin
   values[x][y-1] := i;
   RegionGrowing(x,y-1,i,image);
   end;
 end;

 if high(values[x]) > y then
  if (values[x][y+1]=0) then
   if (IsAenlich(50, c, c4)) then
    begin
    values[x][y+1] := i;
     RegionGrowing(x,y+1,i,image);
    end;

 end;

end;

procedure TXYValues.StartRegionGrowing(image: TImage; i: integer);
begin
form1.progressbar1.min := 0;
form1.progressbar1.position := 0;
form1.progressbar1.max := 100;

values[leftx][lefty] := i;
RegionGrowing(leftx,lefty,i,image);
end;

function TXYValues.IsAenlich(maxunterschied:Integer; var c1,c2:tcolor):boolean;
var r1,g1,b1,
    r2,g2,b2: byte;
    crgb1,crgb2: Integer;
begin
  c1 := colortorgb(c1);
  c2 := colortorgb(c2);

  r1 := getrvalue(c1); // ROT
  g1 := getgvalue(c1); // GRÜN
  b1 := getbvalue(c1); // BLAU
  r2 := getrvalue(c2); // ROT
  g2 := getgvalue(c2); // GRÜN
  b2 := getbvalue(c2); // BLAU

  if r1+g1+b1 < r2+g2+b2 then
  begin
  crgb1 := r1+g1+b1;
  crgb2 := r2+g2+b2;
  end
  else
  begin
  crgb2 := r1+g1+b1;
  crgb1 := r2+g2+b2;
  end;

result := crgb1 >= crgb2 - maxunterschied;

end;

constructor TXYValues.Create(LengthX, LengthY: Integer);
var x, y: integer;
begin
inherited create;

SetLength(Values,lengthx,lengthy);

for x := 0 to High(values) do
 begin
 for y := 0 to High(values[x]) do
  begin
  Values[x][y] := 0;
  end;
 end;

end;

function TXYValues.NoRegionLeft(i: integer): boolean;
var x,y: Integer;
begin

result := true;

for x := 1 to High(Values) do
 begin
 if result then
 for y := 1 to High(Values[x]) do
  begin
  if result then
  if Values[x][y] < 1 then
   begin
   result := false;
   Leftx := x;
   lefty := y;
   end;

  end;

 end;
end;

//...

procedure TForm1.RegionGrowingButtonClick(Sender: TObject);
var x, i: Integer;
    Regions: TXYValues;
begin
i := 0;
Regions := TXYValues.Create(image1.Width, image1.Height);

while not Regions.NoRegionLeft(i) do
 begin

 inc(i);
 Regions.StartRegionGrowing(image1,i);

 end;

showmessage(inttostr(i));
Regions.Free;
end;