关于亮度和对比度的问题，如何用trackbar平滑调整？
如题，我根据资料写出的程序如下，自己加了trackbar调整，但拖动滑块时容易把图像调花，怎么才能平滑调整呢？请高手指点。
代码如下：
procedure HSLtoRGB(H, S, L: Integer; var R, G, B: Integer);//hsl颜色空间到rgb空间的转换var //类似于返回多个值的函数 Sat, Lum: Double;begin R := 0; G := 0; B := 0; if (H < 360) and (H >= 0) and (S <= 100) and (S >= 0) and (L <= 100) and (L >= 0) then begin if H <= 60 then begin R := 255; G := Round((255 / 60) * H); B := 0; end else if H <= 120 then begin R := Round(255 - (255 / 60) * (H - 60)); G := 255; B := 0; end else if H <= 180 then begin R := 0; G := 255; B := Round((255 / 60) * (H - 120)); end else if H <= 240 then begin R := 0; G := Round(255 - (255 / 60) * (H - 180)); B := 255; end else if H <= 300 then begin R := Round((255 / 60) * (H - 240)); G := 0; B := 255; end else if H < 360 then begin R := 255; G := 0; B := Round(255 - (255 / 60) * (H - 300)); end; Sat := Abs((S - 100) / 100); R := Round(R - ((R - 128) * Sat)); G := Round(G - ((G - 128) * Sat)); B := Round(B - ((B - 128) * Sat)); Lum := (L - 50) / 50; if Lum > 0 then begin R := Round(R + ((255 - R) * Lum)); G := Round(G + ((255 - G) * Lum)); B := Round(B + ((255 - B) * Lum)); end else if Lum < 0 then begin R := Round(R + (R * Lum)); G := Round(G + (G * Lum)); B := Round(B + (B * Lum)); end; end;end;procedure RGBtoHSL(R, G, B: Integer; var H, S, L: Integer);// RGB空间到HSL空间的转换var Delta: Double; CMax, CMin: Double; Red, Green, Blue, Hue, Sat, Lum: Double;begin Red := R / 255; Green := G / 255; Blue := B / 255; CMax := Max(Red, Max(Green, Blue)); CMin := Min(Red, Min(Green, Blue)); Lum := (CMax + CMin) / 2; if CMax = CMin then begin Sat := 0; Hue := 0; end else begin if Lum < 0.5 then Sat := (CMax - CMin) / (CMax + CMin) else Sat := (cmax - cmin) / (2 - cmax - cmin); delta := CMax - CMin; if Red = CMax then Hue := (Green - Blue) / Delta else if Green = CMax then Hue := 2 + (Blue - Red) / Delta else Hue := 4.0 + (Red - Green) / Delta; Hue := Hue / 6; if Hue < 0 then Hue := Hue + 1; end; H := Round(Hue * 360); S := Round(Sat * 100); L := Round(Lum * 100);end;//亮度调节procedure TFormMain.TrackBarBrightnessChange(Sender: TObject);var bmp: TBITMAP; x, y, ScanlineBytes,i,DeltaP: integer; p: prgbtriplearray; RVALUE, bvalue, gvalue: integer; hVALUE, sVALUE, lVALUE: integer;begin self.DoubleBuffered := true; //设置双缓冲 if imgCarPhoto.Picture.Graphic <> nil then else begin TrackBarBrightness.Position:=50; OriginalBrightnessPosition:=TrackBarBrightness.Position; Label6.Caption:='亮度 ' + IntToStr(OriginalBrightnessPosition); exit; end; bmp := TBITMAP.Create; bmp.Assign(imgCarPhoto.Picture.Bitmap); //加载位图 bmp.PixelFormat := pf24bit; //指定为24位 p := bmp.ScanLine[0]; ScanlineBytes := integer(bmp.ScanLine[1]) - integer(bmp.ScanLine[0]); //获取两行间距，此法只需执行Scanline两次，速度快，是优化的 i:=TrackBarBrightness.Position; DeltaP:=i - OriginalBrightnessPosition; OriginalBrightnessPosition:=i; Label6.Caption:='亮度 ' + IntToStr(i); for y := 0 to bmp.Height - 1 do begin for x := 0 to bmp.Width - 1 do begin //获取RGB的三个分量值，并进行赋值 RVALUE := p[x].rgbtRed; gVALUE := p[x].rgbtGreen; bVALUE := p[x].rgbtBlue; // 调用前面的RGB转HSL过程，获取HSL三个分量值 RGBtoHSL(RVALUE, gVALUE, bVALUE, hVALUE, sVALUE, lVALUE); //饱和度值进行线性调节。 lVALUE := lVALUE + DeltaP; lVALUE := min(100, lVALUE); lVALUE := max(0, lVALUE); //下面两行是饱和度度减小操作 //SVALUE := SVALUE - 5; //调用前面的HSL空间转RGB颜色空间的过程，获得RGB三个分量 HSLtorgb(hVALUE, sVALUE, lVALUE, rVALUE, gVALUE, bVALUE); p[x].rgbtRed := RVALUE; p[x].rgbtGreen := gVALUE; p[x].rgbtBlue := bVALUE; end; inc(integer(p), ScanlineBytes) //指针递增 end; imgCarPhoto.Picture.Bitmap.Assign(bmp); Bmp.Free;end;//对比度调节procedure TFormMain.TrackBarContrastChange(Sender: TObject);var p: PByteArray; x, y, i, DeltaP: Integer; Bmp: TBitmap;begin self.DoubleBuffered := true; //设置双缓冲 if imgCarPhoto.Picture.Graphic <> nil then else begin TrackBarContrast.Position:=128; OriginalContrastPosition:=TrackBarContrast.Position; Label5.Caption:='对比度 ' + IntToStr(OriginalContrastPosition); exit; end; Bmp := TBitmap.Create; Bmp.Assign(ImgCarPhoto.Picture.Bitmap); Bmp.PixelFormat := pf24Bit; i:=TrackBarContrast.Position; DeltaP:=i - OriginalContrastPosition; OriginalContrastPosition:=i; Label5.Caption:='对比度 ' + IntToStr(i); for y := 0 to Bmp.Height - 1 do begin p := Bmp.scanline[y]; for x := 0 to Bmp.Width - 1 do begin //确定阀值为128 if (p[x * 3] < 246) and (p[x * 3] > 128) and (p[x * 3 + 1] > 128) and (p[x * 3 + 1] < 246) and (p[x * 3 + 2] > 128) and (p[x * 3 + 2] < 246) then begin p[x * 3] := Min(246, Max(128, p[x * 3] + DeltaP)); p[x * 3 + 1] := Min(246, Max(128, p[x * 3 + 1] + DeltaP)); p[x * 3 + 2] := Min(246, Max(128, p[x * 3 + 2] + DeltaP)); end; if (p[x * 3] > 10) and (p[x * 3] < 128) and (p[x * 3 + 1] > 10) and (p[x * 3 + 1] < 128) and (p[x * 3 + 2] > 10) and (p[x * 3 + 2] < 128) then begin p[x * 3] := Min(128, Max(10, p[x * 3] - DeltaP)); p[x * 3 + 1] := Min(128, Max(10, p[x * 3 + 1] - DeltaP)); p[x * 3 + 2] := Min(128, Max(10, p[x * 3 + 2] - DeltaP)); end; end; end; ImgCarPhoto.Picture.Bitmap.Assign(Bmp); Bmp.Free;end;
