Сделать картинке 2D свертку

{
 This function performs a 2D convolution on an image.
 It can be used for a very wide range of image processing operations
 such as image smoothing, anti-aliasing, edge detection,
 detail enhancment, etc. It is very fast.
}
uses
 Graphics, Windows;
type
 TRGBTripleArray = array[0..10000] of TRGBTriple;
 PRGBTripleArray = ^TRGBTripleArray;
 T3x3FloatArray = array[0..2] of array[0..2] of Extended;
implementation
function Convolve(ABitmap: TBitmap; AMask: T3x3FloatArray;
 ABias: Integer): TBitmap;
var
 LRow1, LRow2, LRow3, LRowOut: PRGBTripleArray;
 LRow, LCol: integer;
 LNewBlue, LNewGreen, LNewRed: Extended;
 LCoef: Extended;
begin
 LCoef := 0;
 for LRow := 0 to 2 do
 for LCol := 0 to 2 do
 LCoef := LCoef + AMask[LCol, LRow];
 if LCoef = 0 then LCoef := 1;
 Result := TBitmap.Create;
 Result.Width := ABitmap.Width - 2;
 Result.Height := ABitmap.Height - 2;
 Result.PixelFormat := pf24bit;
 LRow2 := ABitmap.ScanLine[0];
 LRow3 := ABitmap.ScanLine[1];
 for LRow := 1 to ABitmap.Height - 2 do
 begin
 LRow1 := LRow2;
 LRow2 := LRow3;
 LRow3 := ABitmap.ScanLine[LRow + 1];
 LRowOut := Result.ScanLine[LRow - 1];
 for LCol := 1 to ABitmap.Width - 2 do
 begin
 LNewBlue :=
 (LRow1[LCol - 1].rgbtBlue * AMask[0,0]) + (LRow1[LCol].rgbtBlue * AMask[1,0]) +
 (LRow1[LCol + 1].rgbtBlue * AMask[2,0]) +
 (LRow2[LCol - 1].rgbtBlue * AMask[0,1]) + (LRow2[LCol].rgbtBlue * AMask[1,1]) +
 (LRow2[LCol + 1].rgbtBlue * AMask[2,1]) +
 (LRow3[LCol - 1].rgbtBlue * AMask[0,2]) + (LRow3[LCol].rgbtBlue * AMask[1,2]) +
 (LRow3[LCol + 1].rgbtBlue * AMask[2,2]);
 LNewBlue := (LNewBlue / LCoef) + ABias;
 if LNewBlue > 255 then
 LNewBlue := 255;
 if LNewBlue < 0 then
 LNewBlue := 0;
 LNewGreen :=
 (LRow1[LCol - 1].rgbtGreen * AMask[0,0]) + (LRow1[LCol].rgbtGreen * AMask[1,0]) +
 (LRow1[LCol + 1].rgbtGreen * AMask[2,0]) +
 (LRow2[LCol - 1].rgbtGreen * AMask[0,1]) + (LRow2[LCol].rgbtGreen * AMask[1,1]) +
 (LRow2[LCol + 1].rgbtGreen * AMask[2,1]) +
 (LRow3[LCol - 1].rgbtGreen * AMask[0,2]) + (LRow3[LCol].rgbtGreen * AMask[1,2]) +
 (LRow3[LCol + 1].rgbtGreen * AMask[2,2]);
 LNewGreen := (LNewGreen / LCoef) + ABias;
 if LNewGreen > 255 then
 LNewGreen := 255;
 if LNewGreen < 0 then
 LNewGreen := 0;
 LNewRed :=
 (LRow1[LCol - 1].rgbtRed * AMask[0,0]) + (LRow1[LCol].rgbtRed * AMask[1,0])
 + (LRow1[LCol + 1].rgbtRed * AMask[2,0]) +
 (LRow2[LCol - 1].rgbtRed * AMask[0,1]) + (LRow2[LCol].rgbtRed * AMask[1,1])
 + (LRow2[LCol + 1].rgbtRed * AMask[2,1]) +
 (LRow3[LCol - 1].rgbtRed * AMask[0,2]) + (LRow3[LCol].rgbtRed * AMask[1,2])
 + (LRow3[LCol + 1].rgbtRed * AMask[2,2]);
 LNewRed := (LNewRed / LCoef) + ABias;
 if LNewRed > 255 then
 LNewRed := 255;
 if LNewRed < 0 then
 LNewRed := 0;
 LRowOut[LCol - 1].rgbtBlue := Trunc(LNewBlue);
 LRowOut[LCol - 1].rgbtGreen := Trunc(LNewGreen);
 LRowOut[LCol - 1].rgbtRed := Trunc(LNewRed);
 end;
 end;
end;
// example use
// edge detection
procedure TForm1.Button1Click(Sender: TObject);
var
 LMask: T3x3FloatArray;
begin
 LMask[0,0] := -1;
 LMask[1,0] := -1;
 LMask[2,0] := -1;
 LMask[0,1] := -1;
 LMask[1,1] := 8;
 LMask[2,1] := -1;
 LMask[0,2] := -1;
 LMask[1,2] := -1;
 LMask[2,2] := -1;
 Image1.Picture.Bitmap := Convolve(Image1.Picture.Bitmap, LMask, 0);
end;
Source: http://www.swissdelphicenter.ch
ID: 03903
Category:Графика
Category:Bitmap