delphi 图像处理 二值化

procedure TDR_QM_ZP_Form.Image_EZH(  Bmp: TBitmap  );
var

    p: PByteArray;
    Gray, x, y: Integer;

begin

    //设置为24位真彩色
    Bmp.PixelFormat := pf24Bit;
    randomize;
    for y := 0 to Bmp.Height - 1 do
    begin
        p := Bmp.scanline[y];
        for x := 0 to Bmp.Width - 1 do
        begin
            //一个象素点三个字节
            Gray := Round(p[x * 3 + 2] * 0.3 + p[x * 3 + 1] * 0.59 + p[x
                * 3] * 0.11);
            if gray > 128 then //全局阀值128
            begin
                p[x * 3] := 255;
                p[x * 3 + 1] := 255;
                p[x * 3 + 2] := 255;
            end
            else
            begin
                p[x * 3] := 0;
                p[x * 3 + 1] := 0;
                p[x * 3 + 2] := 0;
            end;
        end;
    end;

end;