由Delphi中的图像灰度化代码看基本图像处理
Delphi中改变图片(bitmap)的亮度、对比度、饱和度

Delphi中改变图⽚(bitmap)的亮度、对⽐度、饱和度最近在做视频处理相关的⼯作,遇到⼀些图⽚处理的问题,从别处找到解决的代码。
其中对⽐度调节的代码处理结果看起来不太舒服,暂时没时间仔细研究,先放在这⾥。
// 改亮度function ChangeBrightness(bmp: TBitmap; s: Integer): Boolean;varp: PByteArray;x, y: Integer;begintry//24位真彩⾊Bmp.PixelFormat := pf24Bit;bmp.Canvas.Lock;for y := 0 to Bmp.Height - 1 dobeginp := Bmp.scanline[y];for x := 0 to Bmp.Width - 1 dobegin//每个象素点的R、G、B分量进⾏调节beginif s > 0 thenbeginp[x * 3] := Min(255, p[x * 3] + s); //不能越界,限制在0~255p[x * 3 + 1] := Min(255, p[x * 3 + 1] + s);p[x * 3 + 2] := Min(255, p[x * 3 + 2] + s);endelsebeginp[x * 3] := max(0, p[x * 3] + s); //不能越界,限制在-255~0p[x * 3 + 1] := max(0, p[x * 3 + 1] + s);p[x * 3 + 2] := max(0, p[x * 3 + 2] + s);end;end;end;end;bmp.Canvas.Unlock;Result := true;exceptResult := false;end;end;// 改对⽐度function ChangeContrast(bmp: TBitmap; s: Integer): Boolean;constCMid = 128;CMin = 10;CMax = 246;varp: PByteArray;x, y: Integer;begintry//24位真彩⾊Bmp.PixelFormat := pf24Bit;bmp.Canvas.Lock;for y := 0 to Bmp.Height - 1 dobeginp := Bmp.ScanLine[y];for x := 0 to Bmp.Width - 1 dobegin//确定阀值为128if (p[x*3] > CMid) and (p[x*3] <= CMax)and (p[x*3+1] > CMid) and (p[x*3+1] <= CMax)and (p[x*3+2] > CMid) and (p[x*3+2] <= CMax) thenbeginp[x*3] := Min(255, p[x*3] + s * p[x*3] div (p[x*3]+p[x*3+1]+p[x*3+2]));p[x*3+1]:= Min(255, p[x*3+1]+ s * p[x*3+1] div (p[x*3]+p[x*3+1]+p[x*3+2]));p[x*3+2]:= Min(255, p[x*3+2]+ s * p[x*3+2] div (p[x*3]+p[x*3+1]+p[x*3+2]));end;if (p[x*3] > CMin) and (p[x*3] <= CMid)and (p[x*3+1] > CMin) and (p[x*3+1] <= CMid)and (p[x*3+2] > CMin) and (p[x*3+2] <= CMid) thenbeginp[x*3] := Max(0, p[x*3] - s * p[x*3] div (p[x*3]+p[x*3+1]+p[x*3+2]));p[x*3+1]:= Max(0, p[x*3+1]- s * p[x*3+1] div (p[x*3]+p[x*3+1]+p[x*3+2])); p[x*3+2]:= Max(0, p[x*3+2]- s * p[x*3+2] div (p[x*3]+p[x*3+1]+p[x*3+2])); end;end;end;bmp.Canvas.Unlock;Result := true;exceptResult := false;end;end;// 改饱和度function ChangeSaturation(bmp: TBitmap; ValueChange: Integer): Boolean; constCMax = 255;varGrays: array[0..767] of Integer;Alpha: array[0..255] of Word;Gray, x, y: Integer;SrcRGB: PRGBTriple;i: Byte;beginValueChange := ValueChange + 255;for i := 0 to CMax dobeginAlpha[i] := (i * ValueChange) shr 8;end;x := 0;for i := 0 to CMax dobeginGray := i - Alpha[i];Grays[x] := Gray;Inc(x);Grays[x] := Gray;inc(x);Grays[x] := Gray;Inc(x);end;for y := 0 to bmp.Height - 1 dobeginSrcRGB := bmp.ScanLine[y];for x := 0 to bmp.Width - 1 dobeginGray := Grays[SrcRGB.rgbtRed + SrcRGB.rgbtBlue + SrcRGB.rgbtGreen]; if Gray + Alpha[SrcRGB.rgbtRed] > 0 thenSrcRGB.rgbtRed := Min(CMax, Gray + Alpha[SrcRGB.rgbtRed])elseSrcRGB.rgbtRed := 0;if Gray + Alpha[SrcRGB.rgbtGreen] > 0 thenSrcRGB.rgbtGreen := Min(CMax, Gray + Alpha[SrcRGB.rgbtGreen])elseSrcRGB.rgbtGreen := 0;if Gray + Alpha[SrcRGB.rgbtBlue] > 0 thenSrcRGB.rgbtBlue := Min(CMax, Gray + Alpha[SrcRGB.rgbtBlue])elseSrcRGB.rgbtBlue := 0;Inc(SrcRGB);end;end;end;。
Delphi实现计算机视觉常用图像处理算法

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( 2 ) 2 6 0 0 — al oe l @ cu teu c 0 3 6 4 13 ;图形 , 成一 些简 单 的 图像功 能。利 用这些 对 完 象、 部件 的方法 , 以方便地绘制各种常用图形 ; 可 通过 设置 它们 的属性 , 能得 到不 同风 格 的 图形 。另外 , 过 通 对鼠标事件的定义 , 可以方便地设计 图形绘制程序。
D lh 中的各 图像编 程 对象 见 图 1 epi 。
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Delphi图形图像处理

见例子
画矩形
StretchDraw StretchDraw(Const Rect : TRcct : Graphic : TGraphic); 此方法在Rect参数指定的矩形内画一图像。图像 延伸改变大小以适应矩形。 Rectangle Rectangle(X1,y1,x2,y2 : Integer); Rectangle方法在画布上用当前画刷绘制矩形, (x1,y1)是矩形的左上角,(x2,y2)是矩形的右下 角。
三.图像对象概述 3.1. TGraphic对象
TGraphic对象是 TBitmap ,TIcon,Tmetafile对象的基类。 如果知道图像的具体类型( 如位图, 图标 元文件) , 则应将图像贮存在相应类型的 对象中( 如TBitmap,TIcon,Tmetafile), 否则应该使用可贮存任何图像类型的 TPicture对象。
把点连成线
Polygon Polygon(Points : array of TPrint); Polygon方法在画布上绘制一系列的点,各点依 次连成线,最后将首尾两点相接形成一个区域, 并用当前笔刷填充此区域。 Polyline Polyline(Ports : array of TPort); Polyline方法在画布上用当前画笔绘制一系列的 点,各点依次连成线。
Tbrush对象方法
(1)Assign:向另一个对象赋值 (2)Create:创建一个TBrush对象实例。 (3)Destroy:释放一个TBrush对象实例。 (4)OwnHandle:用来确保对更基本的Qbrush 类实例的权限。当需要接受QBrush handle使用 或销毁权限时需要用到这个过程。 (5)ReleaseHandle:用来把TBrush 从 QBrush handle中分离出来,当需要把TBrush handle 给一段程序或一个类时,用到这个函数。
Delphi基本图像处理方法.

本文实例汇总了Delphi基本图像处理方法。
分享给大家供大家参考。
具体分析如下: //浮雕 procedureEmboss(SrcBmp,DestBmp:TBitmap;AzimuthChange:integer;overload; var i, j, Gray, Azimuthvalue, R, G, B: integer; SrcRGB, SrcRGB1, SrcRGB2, DestRGB: pRGBTriple; begin for i := 0 to SrcBmp.Height - 1 do begin SrcRGB := SrcBmp.ScanLine[i]; DestRGB := DestBmp.ScanLine[i]; if (AzimuthChange >= -180 and (AzimuthChange < -135 then begin if i > 0 then SrcRGB1 := SrcBmp.ScanLine[i-1] else SrcRGB1 := SrcRGB; Inc(SrcRGB1; SrcRGB2 := SrcRGB; Inc(SrcRGB2; end else if (AzimuthChange >= -135 and (AzimuthChange < -90 then begin if i > 0 thenSrcRGB1 := SrcBmp.ScanLine[i-1] else SrcRGB1 := SrcRGB; SrcRGB2 := SrcRGB1; Inc(SrcRGB2; end else if (AzimuthChange >= -90 and (AzimuthChange < -45 then begin if i > 0 then SrcRGB1 := SrcBmp.ScanLine[i-1] else SrcRGB1 := SrcRGB; SrcRGB2 := SrcRGB1; end else if (AzimuthChange >= -45 and (AzimuthChange < 0 then begin SrcRGB1 := SrcRGB; if i > 0 then SrcRGB2 := SrcBmp.ScanLine[i-1] else SrcRGB2 := SrcRGB; end else if (AzimuthChange >= 0 and (AzimuthChange < 45 then begin SrcRGB2 := SrcRGB; if (i < SrcBmp.Height - 1 then SrcRGB1 := SrcBmp.ScanLine[i+1] else SrcRGB1 := SrcRGB; end else if (AzimuthChange >= 45 and (AzimuthChange < 90 then begin if (i < SrcBmp.Height - 1 then SrcRGB1 := SrcBmp.ScanLine[i+1] else SrcRGB1 := SrcRGB; SrcRGB2 := SrcRGB1; end else if (AzimuthChange >= 90 and (AzimuthChange < 135 then begin if (i < SrcBmp.Height - 1 then SrcRGB1 := SrcBmp.ScanLine[i+1] else SrcRGB1 := SrcRGB; SrcRGB2 := SrcRGB1; Inc(SrcRGB1; end else if (AzimuthChange >= 135 and (AzimuthChange <= 180 then begin if (i < SrcBmp.Height - 1 then SrcRGB2 := SrcBmp.ScanLine[i+1] else SrcRGB2 := SrcRGB; Inc(SrcRGB2; SrcRGB1 := SrcRGB; Inc(SrcRGB1; end; for j := 0 to SrcBmp.Width - 1 do begin if (AzimuthChange >= -180 and (AzimuthChange < -135 then begin Azimuthvalue := AzimuthChange + 180; R:=SrcRGB.rgbtRed-((SrcRGB1.rgbtRed*Azimuthvalue div 45-((SrcRGB2.rgbtRed*(45-Azimuthvalue div45+78; G:=SrcRGB.rgbtGreen-((SrcRGB1.rgbtGreen*Azimuthvalue div 45-((SrcRGB2.rgbtGreen*(45-Azimuthvalue div 45+78; B:=SrcRGB.rgbtBlue-((SrcRGB1.rgbtBlue*Azimuthvalue div 45-((SrcRGB2.rgbtBlue*(45-Azimuthvalue div 45+78; end else if (AzimuthChange >= -135 and (AzimuthChange < -90 then begin Azimuthvalue := AzimuthChange + 135; R:=SrcRGB.rgbtRed-((SrcRGB1.rgbtRed*Azimuthvalue div 45-((SrcRGB2.rgbtRed*(45-Azimuthvalue div 45+78; G:=SrcRGB.rgbtGreen-((SrcRGB1.rgbtGreen*Azimuthvalue div 45-((SrcRGB2.rgbtGreen*(45-Azimuthvalue div 45+78; B:=SrcRGB.rgbtBlue-((SrcRGB1.rgbtBlue*Azimuthvalue div 45-((SrcRGB2.rgbtBlue*(45-Azimuthvalue div 45+78; end else if (AzimuthChange >= -90 and (AzimuthChange < -45 then begin if j=1 then Inc(SrcRGB1,-1; Azimuthvalue := AzimuthChange + 90;R:=SrcRGB.rgbtRed-((SrcRGB1.rgbtRed*Azimuthvalue div 45-((SrcRGB2.rgbtRed*(45-Azimuthvalue div 45+78; G:=SrcRGB.rgbtGreen-((SrcRGB1.rgbtGreen*Azimuthvalue div 45-((SrcRGB2.rgbtGreen*(45-Azimuthvalue div 45+78; B:=SrcRGB.rgbtBlue-((SrcRGB1.rgbtBlue*Azimuthvalue div 45-((SrcRGB2.rgbtBlue*(45-Azimuthvalue div 45+78; end else if (AzimuthChange >= -45 and (AzimuthChange < 0 then begin if j=1 then begin Inc(SrcRGB1,-1; Inc(SrcRGB2,-1; end; Azimuthvalue := AzimuthChange + 45; R:=SrcRGB.rgbtRed-((SrcRGB1.rgbtRed*Azimuthvalue div 45-((SrcRGB2.rgbtRed*(45-Azimuthvalue div 45+78; G:=SrcRGB.rgbtGreen-((SrcRGB1.rgbtGreen*Azimuthvalue div 45-((SrcRGB2.rgbtGreen*(45-Azimuthvalue div 45+78; B:=SrcRGB.rgbtBlue-((SrcRGB1.rgbtBlue*Azimuthvalue div 45-((SrcRGB2.rgbtBlue*(45-Azimuthvalue div 45+78; end else if (AzimuthChange >= 0 and (AzimuthChange < 45 then begin if j=1 then begin Inc(SrcRGB1,-1; Inc(SrcRGB2,-1; end; Azimuthvalue := AzimuthChange; R:=SrcRGB.rgbtRed-((SrcRGB1.rgbtRed*Azimuthvalue div 45-((SrcRGB2.rgbtRed*(45-Azimuthvalue div 45+78; G:=SrcRGB.rgbtGreen-((SrcRGB1.rgbtGreen*Azimuthvalue div 45-((SrcRGB2.rgbtGreen*(45-Azimuthvalue div 45+78; B:=SrcRGB.rgbtBlue-((SrcRGB1.rgbtBlue*Azimuthvalue div 45-((SrcRGB2.rgbtBlue*(45-Azimuthvalue div 45+78; end else if (AzimuthChange >= 45and (AzimuthChange < 90 then begin if j=1 then Inc(SrcRGB2,-1; Azimuthvalue := AzimuthChange - 45; R:=SrcRGB.rgbtRed-((SrcRGB1.rgbtRed*Azimuthvalue div 45-((SrcRGB2.rgbtRed*(45-Azimuthvalue div 45+78; G:=SrcRGB.rgbtGreen-((SrcRGB1.rgbtGreen*Azimuthvalue div 45-((SrcRGB2.rgbtGreen*(45-Azimuthvalue div 45+78; B:=SrcRGB.rgbtBlue-((SrcRGB1.rgbtBlue*Azimuthvalue div 45-((SrcRGB2.rgbtBlue*(45-Azimuthvalue div 45+78; end else if (AzimuthChange >= 90 and (AzimuthChange < 135 then begin Azimuthvalue := AzimuthChange - 90;R:=SrcRGB.rgbtRed-((SrcRGB1.rgbtRed*Azimuthvalue div 45-((SrcRGB2.rgbtRed*(45-Azimuthvalue div 45+78; G:=SrcRGB.rgbtGreen-((SrcRGB1.rgbtGreen*Azimuthvalue div 45-((SrcRGB2.rgbtGreen*(45-Azimuthvalue div 45+78; B:=SrcRGB.rgbtBlue-((SrcRGB1.rgbtBlue*Azimuthvalue div 45-((SrcRGB2.rgbtBlue*(45-Azimuthvalue div 45+78; end else if (AzimuthChange >= 135 and (AzimuthChange <= 180 then begin Azimuthvalue := AzimuthChange - 135;R:=SrcRGB.rgbtRed-((SrcRGB1.rgbtRed*Azimuthvalue div 45-((SrcRGB2.rgbtRed*(45-Azimuthvalue div 45+78; G:=SrcRGB.rgbtGreen-((SrcRGB1.rgbtGreen*Azimuthvalue div 45-((SrcRGB2.rgbtGreen*(45-Azimuthvalue div 45+78; B:=SrcRGB.rgbtBlue-((SrcRGB1.rgbtBlue*Azimuthvalue div 45-((SrcRGB2.rgbtBlue*(45-Azimuthvalue div 45+78; end; R:=Min(R,255; R:=Max(R,0; G:=Min(G,255; G:=Max(G,0; B:=Min(B,255; B:=Max(B,0; Gray := (R shr 2 + (R shr 4 + (G shr 1 + (G shr 4 + (B shr 3; DestRGB.rgbtRed:=Gray; DestRGB.rgbtGreen:=Gray; DestRGB.rgbtBlue:=Gray; if (j=-180 and (AzimuthChange<-135 or ((AzimuthChange>=90 and (AzimuthChange<=180 then begin Inc(SrcRGB1; end; if (j=135 and (AzimuthChange<180 or ((AzimuthChange>=-180 and (AzimuthChange<=-90 then begin Inc(SrcRGB2; end;Inc(SrcRGB; Inc(DestRGB; end; end; end; procedureEmboss(Bmp:TBitmap;AzimuthChange:integer;ElevationChange:integer;WeightChange: integer;overload; var DestBmp:TBitmap; begin DestBmp:=TBitmap.Create; DestBmp.Assign(Bmp;Emboss(Bmp,DestBmp,AzimuthChange,ElevationChange,WeightChange;Bmp.Assign(DestBmp; end; //反色 procedure Negative(Bmp:TBitmap; var i, j: Integer; PRGB: pRGBTriple; begin Bmp.PixelFormat:=pf24Bit; for i := 0 to Bmp.Height - 1 do begin PRGB := Bmp.ScanLine[i]; for j := 0 to Bmp.Width - 1 do beginPRGB^.rgbtRed :=not PRGB^.rgbtRed ; PRGB^.rgbtGreen :=not PRGB^.rgbtGreen; PRGB^.rgbtBlue :=not PRGB^.rgbtBlue; Inc(PRGB; end; end; end; //曝光 procedure Exposure(Bmp:TBitmap; var i, j: integer; PRGB: pRGBTriple; beginBmp.PixelFormat:=pf24Bit; for i := 0 to Bmp.Height - 1 do begin PRGB :=Bmp.ScanLine[i]; for j := 0 to Bmp.Width - 1 do begin if PRGB^.rgbtRed<128 then PRGB^.rgbtRed :=not PRGB^.rgbtRed ; if PRGB^.rgbtGreen<128 thenPRGB^.rgbtGreen :=not PRGB^.rgbtGreen; if PRGB^.rgbtBlue<128 thenPRGB^.rgbtBlue :=not PRGB^.rgbtBlue; Inc(PRGB; end; end; end; //模糊 procedure Blur(SrcBmp:TBitmap; var i, j:Integer; SrcRGB:pRGBTriple; SrcNextRGB:pRGBTriple; SrcPreRGB:pRGBTriple; Value:Integer; procedure IncRGB; begin Inc(SrcPreRGB;Inc(SrcRGB; Inc(SrcNextRGB; end; procedure DecRGB; begin Inc(SrcPreRGB,-1;Inc(SrcRGB,-1; Inc(SrcNextRGB,-1; end; begin SrcBmp.PixelFormat:=pf24Bit; for i := 0 to SrcBmp.Height - 1 do begin if i > 0 then SrcPreRGB:=SrcBmp.ScanLine[i-1] else SrcPreRGB := SrcBmp.ScanLine[i]; SrcRGB := SrcBmp.ScanLine[i]; if i <SrcBmp.Height - 1 then SrcNextRGB:=SrcBmp.ScanLine[i+1] elseSrcNextRGB:=SrcBmp.ScanLine[i]; for j := 0 to SrcBmp.Width - 1 do begin if j > 0 then DecRGB; Value:=SrcPreRGB.rgbtRed+SrcRGB.rgbtRed+SrcNextRGB.rgbtRed; if j > 0 then IncRGB;Value:=Value+SrcPreRGB.rgbtRed+SrcRGB.rgbtRed+SrcNextRGB.rgbtRed; if j < SrcBmp.Width - 1 then IncRGB;Value:=(Value+SrcPreRGB.rgbtRed+SrcRGB.rgbtRed+SrcNextRGB.rgbtRed div 9; DecRGB; SrcRGB.rgbtRed:=value;if j > 0 then DecRGB;Value:=SrcPreRGB.rgbtGreen+SrcRGB.rgbtGreen+SrcNextRGB.rgbtGreen; if j > 0 thenIncRGB;Value:=Value+SrcPreRGB.rgbtGreen+SrcRGB.rgbtGreen+SrcNextRGB.rgbtGreen; if j < SrcBmp.Width - 1 then IncRGB;Value:=(Value+SrcPreRGB.rgbtGreen+SrcRGB.rgbtGreen+SrcNextRGB.rgbtGreen div 9; DecRGB; SrcRGB.rgbtGreen:=value; if j > 0 then DecRGB;Value:=SrcPreRGB.rgbtBlue+SrcRGB.rgbtBlue+SrcNextRGB.rgbtBlue; if j > 0 then IncRGB; Value:=Value+SrcPreRGB.rgbtBlue+SrcRGB.rgbtBlue+SrcNextRGB.rgbtBlue; if j < SrcBmp.Width - 1 then IncRGB;Value:=(Value+SrcPreRGB.rgbtBlue+SrcRGB.rgbtBlue+SrcNextRGB.rgbtBlue div 9; DecRGB; SrcRGB.rgbtBlue:=value; IncRGB; end; end; end; //锐化 procedureSharpen(SrcBmp:TBitmap; var i, j: integer; SrcRGB: pRGBTriple; SrcPreRGB: pRGBTriple; Value: integer; begin SrcBmp.PixelFormat:=pf24Bit; for i := 0 to SrcBmp.Height - 1 do begin SrcRGB := SrcBmp.ScanLine[i]; if i > 0 then SrcPreRGB:=SrcBmp.ScanLine[i-1] else SrcPreRGB:=SrcBmp.ScanLine[i]; for j := 0 to SrcBmp.Width - 1 do begin if j = 1 then Dec(SrcPreRGB;Value:=SrcRGB.rgbtRed+(SrcRGB.rgbtRed-SrcPreRGB.rgbtRed div 2;Value:=Max(0,Value; Value:=Min(255,Value; SrcRGB.rgbtRed:=value;Value:=SrcRGB.rgbtGreen+(SrcRGB.rgbtGreen-SrcPreRGB.rgbtGreen div 2;Value:=Max(0,Value; Value:=Min(255,Value; SrcRGB.rgbtGreen:=value;Value:=SrcRGB.rgbtBlue+(SrcRGB.rgbtBlue-SrcPreRGB.rgbtBlue div 2;Value:=Max(0,Value; Value:=Min(255,Value; SrcRGB.rgbtBlue:=value; Inc(SrcRGB; Inc(SrcPreRGB; end; end; end; [图像的旋转和翻转] 以下代码用ScanLine配合指针移动实现,用于24位色! //旋转90度 procedure Rotate90(const Bitmap:TBitmap; var i,j:Integer; rowIn,rowOut:pRGBTriple; Bmp:TBitmap; Width,Height:Integer; begin Bmp:=TBitmap.Create; Bmp.Width := Bitmap.Height; Bmp.Height := Bitmap.Width; Bmp.PixelFormat := pf24bit; Width:=Bitmap.Width-1; Height:=Bitmap.Height-1; for j := 0 to Height do begin rowIn := Bitmap.ScanLine[j]; for i := 0 to Width do beginrowOut := Bmp.ScanLine[i]; Inc(rowOut,Height - j; rowOut^ := rowIn^; Inc(rowIn; end;end; Bitmap.Assign(Bmp; end; //旋转180度 procedure Rotate180(constBitmap:TBitmap; var i,j:Integer; rowIn,rowOut:pRGBTriple; Bmp:TBitmap;Width,Height:Integer; begin Bmp:=TBitmap.Create; Bmp.Width := Bitmap.Width; Bmp.Height := Bitmap.Height; Bmp.PixelFormat := pf24bit; Width:=Bitmap.Width-1; Height:=Bitmap.Height-1; for j := 0 to Height do begin rowIn := Bitmap.ScanLine[j]; for i := 0 to Width do begin rowOut := Bmp.ScanLine[Height - j]; Inc(rowOut,Width - i; rowOut^ := rowIn^; Inc(rowIn; end; end; Bitmap.Assign(Bmp; end; //旋转270度procedure Rotate270(const Bitmap:TBitmap; var i,j:Integer; rowIn,rowOut:pRGBTriple; Bmp:TBitmap; Width,Height:Integer; begin Bmp:=TBitmap.Create; Bmp.Width := Bitmap.Height; Bmp.Height := Bitmap.Width; Bmp.PixelFormat :=pf24bit; Width:=Bitmap.Width-1; Height:=Bitmap.Height-1; for j := 0 to Height do begin rowIn := Bitmap.ScanLine[j]; for i := 0 to Width do begin rowOut :=Bmp.ScanLine[Width - i]; Inc(rowOut,j; rowOut^ := rowIn^; Inc(rowIn; end; end; Bitmap.Assign(Bmp; end; //任意角度 functionRotateBitmap(Bitmap:TBitmap;Angle:Integer;BackColor:TColor:TBitmap; vari,j,iOriginal,jOriginal,CosPoint,SinPoint : integer; RowOriginal,RowRotated : pRGBTriple; SinTheta,CosTheta : Extended; AngleAdd : integer; beginResult:=TBitmap.Create; Result.PixelFormat := pf24bit;Result.Canvas.Brush.Color:=BackColor; Angle:=Angle Mod 360; if Angle<0 then Angle:=360-Abs(Angle; if Angle=0 then Result.Assign(Bitmap else if Angle=90 then begin Result.Assign(Bitmap; Rotate90(Result;//如果是旋转90度,直接调用上面的代码 end else if (Angle>90 and (Angle<180 then begin AngleAdd:=90; Angle:=Angle-AngleAdd; end else if Angle=180 then begin Result.Assign(Bitmap; Rotate180(Result;//如果是旋转180度,直接调用上面的过程 end else if (Angle>180 and (Angle<270 then begin AngleAdd:=180; Angle:=Angle-AngleAdd; end else if Angle=270 then begin Result.Assign(Bitmap; Rotate270(Result;//如果是旋转270度,直接调用上面的过程end else if (Angle>270 and (Angle<360 then begin AngleAdd:=270; Angle:=Angle-AngleAdd; end else AngleAdd:=0; if (Angle>0 and (Angle<90 then begin SinCos((Angle+ AngleAdd * Pi / 180, SinTheta, CosTheta; if (SinTheta * CosTheta < 0 then begin Result.Width := Round(Abs(Bitmap.Width * CosTheta - Bitmap.Height * SinTheta; Result.Height := Round(Abs(Bitmap.Width * SinTheta - Bitmap.Height * CosTheta; end else begin Result.Width := Round(Abs(Bitmap.Width * CosTheta + Bitmap.Height * SinTheta; Result.Height := Round(Abs(Bitmap.Width * SinTheta + Bitmap.Height * CosTheta; end; CosTheta:=Abs(CosTheta; SinTheta:=Abs(SinTheta; if (AngleAdd=0 or (AngleAdd=180 then begin CosPoint:=Round(Bitmap.Height*CosTheta;SinPoint:=Round(Bitmap.Height*SinTheta; end else beginSinPoint:=Round(Bitmap.Width*CosTheta; CosPoint:=Round(Bitmap.Width*SinTheta; end; for j := 0 to Result.Height-1 do begin RowRotated := Result.Scanline[j]; for i := 0 to Result.Width-1 do begin Case AngleAdd of 0: begin jOriginal := Round((j+1*CosTheta-(i+1-SinPoint*SinTheta-1; iOriginal := Round((i+1*CosTheta-(CosPoint-j-1*SinTheta-1; end; 90: begin iOriginal := Round((j+1*SinTheta-(i+1-SinPoint*CosTheta-1; jOriginal := Bitmap.Height-Round((i+1*SinTheta-(CosPoint-j-1*CosTheta; end; 180: begin jOriginal := Bitmap.Height-Round((j+1*CosTheta-(i+1-SinPoint*SinTheta; iOriginal := Bitmap.Width-Round((i+1*CosTheta-(CosPoint-j-1*SinTheta; end; 270: begin iOriginal := Bitmap.Width-Round((j+1*SinTheta-(i+1-SinPoint*CosTheta; jOriginal := Round((i+1*SinTheta-(CosPoint-j-1*CosTheta-1; end; end; if (iOriginal >= 0 and (iOriginal <= Bitmap.Width-1and (jOriginal >= 0 and (jOriginal <=Bitmap.Height-1 then begin RowOriginal := Bitmap.Scanline[jOriginal];Inc(RowOriginal,iOriginal; RowRotated^ := RowOriginal^; Inc(RowRotated; end else begin Inc(RowRotated; end; end; end; end; end; //水平翻转 procedure FlipHorz(const Bitmap:TBitmap; var i,j:Integer; rowIn,rowOut:pRGBTriple; Bmp:TBitmap;Width,Height:Integer; begin Bmp:=TBitmap.Create; Bmp.Width := Bitmap.Width; Bmp.Height := Bitmap.Height; Bmp.PixelFormat := pf24bit; Width:=Bitmap.Width-1; Height:=Bitmap.Height-1; for j := 0 to Height do begin rowIn := Bitmap.ScanLine[j]; for i := 0 to Width do begin rowOut := Bmp.ScanLine[j]; Inc(rowOut,Width - i; rowOut^ := rowIn^; Inc(rowIn; end; end; Bitmap.Assign(Bmp; end; //垂直翻转 procedureFlipVert(const Bitmap:TBitmap; var i,j:Integer; rowIn,rowOut:pRGBTriple;Bmp:TBitmap; Width,Height:Integer; begin Bmp:=TBitmap.Create; Bmp.Width := Bitmap.Height; Bmp.Height := Bitmap.Width; Bmp.PixelFormat := pf24bit;Width:=Bitmap.Width-1; Height:=Bitmap.Height-1; for j := 0 to Height do beginrowIn := Bitmap.ScanLine[j]; for i := 0 to Width do begin rowOut :=Bmp.ScanLine[Height - j]; Inc(rowOut,i; rowOut^ := rowIn^; Inc(rowIn; end; end; Bitmap.Assign(Bmp; end; [亮度、对比度、饱和度的调整] 以下代码用ScanLine配合指针移动实现! function Min(a, b: integer: integer; begin if a < b then result := a else result := b; end; function Max(a, b: integer: integer; begin if a > b then result := a else result := b; end; //亮度调整 procedure BrightnessChange(constSrcBmp,DestBmp:TBitmap;ValueChange:integer; var i, j: integer; SrcRGB, DestRGB: pRGBTriple; begin for i := 0 to SrcBmp.Height - 1 do begin SrcRGB :=SrcBmp.ScanLine[i]; DestRGB := DestBmp.ScanLine[i]; for j := 0 to SrcBmp.Width - 1 do begin if ValueChange > 0 then begin DestRGB.rgbtRed := Min(255, SrcRGB.rgbtRed + ValueChange; DestRGB.rgbtGreen := Min(255, SrcRGB.rgbtGreen + ValueChange; DestRGB.rgbtBlue := Min(255, SrcRGB.rgbtBlue + ValueChange; end else begin DestRGB.rgbtRed := Max(0, SrcRGB.rgbtRed + ValueChange; DestRGB.rgbtGreen := Max(0, SrcRGB.rgbtGreen + ValueChange; DestRGB.rgbtBlue := Max(0,SrcRGB.rgbtBlue + ValueChange; end; Inc(SrcRGB; Inc(DestRGB; end; end; end; //对比度调整 procedure ContrastChange(const SrcBmp,DestBmp:TBitmap;ValueChange:integer; var i, j: integer; SrcRGB, DestRGB: pRGBTriple; begin for i := 0 to SrcBmp.Height - 1 do begin SrcRGB := SrcBmp.ScanLine[i]; DestRGB := DestBmp.ScanLine[i]; for j := 0 to SrcBmp.Width - 1 do begin if ValueChange>=0 then begin if SrcRGB.rgbtRed >= 128 then DestRGB.rgbtRed := Min(255, SrcRGB.rgbtRed + ValueChange else DestRGB.rgbtRed := Max(0, SrcRGB.rgbtRed - ValueChange; if SrcRGB.rgbtGreen >= 128 then DestRGB.rgbtGreen := Min(255, SrcRGB.rgbtGreen + ValueChange else DestRGB.rgbtGreen := Max(0, SrcRGB.rgbtGreen - ValueChange; ifSrcRGB.rgbtBlue >= 128 then DestRGB.rgbtBlue := Min(255, SrcRGB.rgbtBlue + ValueChange else DestRGB.rgbtBlue := Max(0, SrcRGB.rgbtBlue - ValueChange; end else begin if SrcRGB.rgbtRed >= 128 then DestRGB.rgbtRed := Max(128,SrcRGB.rgbtRed + ValueChange else DestRGB.rgbtRed := Min(128, SrcRGB.rgbtRed - ValueChange; if SrcRGB.rgbtGreen >= 128 then DestRGB.rgbtGreen := Max(128, SrcRGB.rgbtGreen + ValueChange else DestRGB.rgbtGreen := Min(128,SrcRGB.rgbtGreen - ValueChange; if SrcRGB.rgbtBlue >= 128 thenDestRGB.rgbtBlue := Max(128, SrcRGB.rgbtBlue + ValueChange elseDestRGB.rgbtBlue := Min(128, SrcRGB.rgbtBlue - ValueChange; end; Inc(SrcRGB; Inc(DestRGB; end; end; end; //饱和度调整 procedure SaturationChange(const SrcBmp,DestBmp:TBitmap;ValueChange:integer; var Grays: array[0..767] of Integer; Alpha: array[0..255] of Word; Gray, x, y: Integer; SrcRGB,DestRGB: pRGBTriple; i: Byte; begin ValueChange:=ValueChange+255; for i := 0 to 255 do Alpha[i] := (i * ValueChange Shr 8; x := 0; for i := 0 to 255 do begin Gray := i - Alpha[i]; Grays[x] := Gray; Inc(x; Grays[x] := Gray; Inc(x; Grays[x] := Gray; Inc(x; end; for y := 0 to SrcBmp.Height - 1 do begin SrcRGB := SrcBmp.ScanLine[Y]; DestRGB := DestBmp.ScanLine[Y]; for x := 0 to SrcBmp.Width - 1 do begin Gray :=Grays[SrcRGB.rgbtRed + SrcRGB.rgbtGreen + SrcRGB.rgbtBlue]; if Gray +Alpha[SrcRGB.rgbtRed]>0 then DestRGB.rgbtRed := Min(255,Gray +Alpha[SrcRGB.rgbtRed] else DestRGB.rgbtRed := 0; if Gray +Alpha[SrcRGB.rgbtGreen]>0 then DestRGB.rgbtGreen := Min(255,Gray +Alpha[SrcRGB.rgbtGreen] else DestRGB.rgbtGreen := 0; if Gray +Alpha[SrcRGB.rgbtBlue]>0 then DestRGB.rgbtBlue := Min(255,Gray +Alpha[SrcRGB.rgbtBlue] else DestRGB.rgbtBlue := 0; Inc(SrcRGB; Inc(DestRGB; end; end; end; //RGB调整 procedureRGBChange(SrcBmp,DestBmp:TBitmap;RedChange,GreenChange,BlueChange:integer; var SrcRGB, DestRGB: pRGBTriple; i,j:integer; begin for i := 0 to SrcBmp.Height- 1 dobegin SrcRGB := SrcBmp.ScanLine[i]; DestRGB :=DestBmp.ScanLine[i]; for j := 0 to SrcBmp.Width - 1 do begin if RedChange> 0 then DestRGB.rgbtRed:= Min(255, SrcRGB.rgbtRed + RedChange else DestRGB.rgbtRed := Max(0, SrcRGB.rgbtRed + RedChange; if GreenChange> 0 then DestRGB.rgbtGreen :=Min(255, SrcRGB.rgbtGreen + GreenChange else DestRGB.rgbtGreen := Max(0, SrcRGB.rgbtGreen + GreenChange; if BlueChange> 0 then DestRGB.rgbtBlue :=Min(255, SrcRGB.rgbtBlue + BlueChange else DestRGB.rgbtBlue := Max(0, SrcRGB.rgbtBlue + BlueChange; Inc(SrcRGB; Inc(DestRGB; end; end; end; [颜色调整] //RGB<=>BGR procedure RGB2BGR(const Bitmap:TBitmap; var X: Integer; Y: Integer; PRGB: pRGBTriple; Color: Byte; begin for Y := 0 to (Bitmap.Height - 1 do begin forX := 0 to (Bitmap.Width - 1 do begin Color := PRGB^.rgbtRed; PRGB^.rgbtRed := PRGB^.rgbtBlue; PRGB^.rgbtBlue := Color; Inc(PRGB; end; end end; end; //灰度化(加权 procedure Grayscale(const Bitmap:TBitmap; var X: Integer; Y: Integer; PRGB: pRGBTriple; Gray: Byte; begin for Y := 0 to (Bitmap.Height - 1 do begin PRGB := Bitmap.ScanLine[Y]; for X := 0 to (Bitmap.Width - 1 do begin Gray := (77 * Red + 151 * Green + 28 * Blue shr 8; PRGB^.rgbtRed:=Gray; PRGB^.rgbtGreen:=Gray;PRGB^.rgbtBlue:=Gray; Inc(PRGB; end; end; end; 绘图区-即窗口显示图像的区域,亦可为全屏幕(在全屏幕下绘图的效果比一般窗口下好)中心点-即要绘图区显示的中心点在原始图像的坐标(声明:这个概念特别重要)先说说图像的放大,要放大一张图片,我们一般的做法是直接放大图像,但本文介绍的方法仅放大我们能够看到的部分,放大分两种情况,一种是放大后比绘图区还要小,这种情况没什么好说,当然是显示全部的图像;第二种是放大后的图像比绘图区大,这才是我们今天要讨论的重点话题,这种情况下我们先要确定图像放大后的大小,然后根据“中心点”计算在原始图像的位置和大小,最后把截取的图像放大到绘图区。
Delphi中GDI+实现图像二值化

Delphi中GDI+实现图像⼆值化// 灰度或者⼆值化彩⾊图像procedure GrayImage(Image: TGpImage; Threshold: Single = 0.0);constColorMatrix: TColorMatrix =((0.3, 0.3, 0.3, 0.0, 0.0),(0.59, 0.59, 0.59, 0.0, 0.0),(0.11, 0.11, 0.11, 0.0, 0.0),(0.0, 0.0, 0.0, 1.0, 0.0),(0.0, 0.0, 0.0, 0.0, 1.0));varTmp: TGpImage;attr: TGpImageAttributes;g: TGpGraphics;beginTmp := Image.Clone;g := TGpGraphics.Create(Image);attr := TGpImageAttributes.Create;tryattr.SetColorMatrix(ColorMatrix); // 灰度化if Threshold > 0.0then // 如果给出了阀值,在灰度图基础上⼆值化attr.SetThreshold(Threshold);g.DrawImage(Tmp, GpRect(0, 0, Image.Width, Image.Height),0, 0, Tmp.Width, Tmp.Height, utPixel, attr);finallyg.Free;attr.Free;Tmp.Free;end;end;procedure TForm1.Button1Click(Sender: TObject);varImage: TGpImage;g: TGpGraphics;beginImage := TGpImage.Create('..mediaFRUIT.jpg');g := TGpGraphics.Create(Handle, False);g.DrawImage(Image, 10, 10, Image.Width, Image.Height);GrayImage(Image, 0.5);g.DrawImage(Image, 220, 10, Image.Width, Image.Height);g.Free;image.Free;end;从例⼦可以看出,彩⾊图像⼆值化,就是在其灰度化基础上给定⼀个0 - 1之间的阀值,所谓阀值就是每种颜⾊成分的分界点。
Delphi的图形处理

Delphi的图形处理Delphi的图形处理......................................................................................................- 1 - 第一章图像处理在可视化编程中的作用及其应用价值.................................- 2 - 第二章图像处理函数.......................................................................................- 2 -2.1 为什么选择Delphi..............................................................................- 2 -2.2 Delphi中用于图形处理的类...............................................................- 2 -2.3 GDI及Canvas类简介.........................................................................- 4 -第三章基本图像处理算法.............................................................................- 13 -3.1柔化和锐化处理.........................................................................................- 13 -3.2 图像混合(透明度)效果..............................................................................- 19 -3.3 转为灰度图像............................................................................................- 22 -3.4 对比度调整和反色处理.............................................................................- 23 -3.5 亮度的调整................................................................................................- 25 -3.6 浮雕效果....................................................................................................- 28 -3.7 马赛克效果................................................................................................- 31 -第一章图像处理在可视化编程中的作用及其应用价值图像处理,是可视化编程的基础内容。
delphi中的图像处理

图像处理基本知识彩色变灰度把一图由彩色变成灰度,也就是把每个像素的RGB各分量变为相同的,就成了灰度图像了pf24bit 模式下用BMP 的ScanLine 可以读取每一行的RGB数据.得到的是一个指针字节顺序是B,G,R亮度Y = 0.229R + 0.587G + 0.114B这个公式相当重要.以后很多图像处理都要用到它.方法1:方法一很简单,把RGB各分量相加,计算平均值,再设为新的RGB方法2:找出RGB 各分量中最大的.再设成新的RGB 值方法3:根据工式: Y = 0.229R + 0.587G + 0.114B算出亮度.新的RGB 各分量都为这个值.(个人认为第三种方法比较科学)代码:(方法一. 其它方法类似)bmp := TBitmap.Create;Bmp.Assign(Image1.Picture.Bitmap);bmp.HandleType :=bmDIB;bmp.PixelFormat := pf24bit;for j := 0 to bmp.Height -1 dobeginp := bmp.ScanLine[j];for i := 0 to Bmp.Width - 1 dobegingray1 :=Byte( (p[i*3] + p[i*3+1] + p[i*3+2]) div 3);p[i*3] := gray1;p[i*3+1]:= gray1;p[i*3+2] := gray1;end;end;Image2.Picture.Bitmap.Assign(bmp);bmp.free;==============================二值化:与灰度不同,二值化只有两种颜色.一般在做一些识别时用得比较多.方法:1, 计算出像素的亮度, 定义一个亮度阈值.2. 亮度大于这个阈值的像素,颜色为白,小于这个阈值的像素,颜色为黑.=======================================亮度调节取各个像素的RGB值,按比例加/减一个增量.也许用亮度公式来算出这个比例,比较科学.按一定比例,把部分的RGB 提升,一部分下降.================================-====Gamma校正(不太明白用在哪里.)分别把RGB 设为Min(255, round(255 * Power((OldValue / 256), 0.45))); NewValue := 255 乘(OldValue /256) 的 0.45 次方======================反色各分量取反.======================爆光小于128的取反。
基于Delphi语言的数字图像处理实验系统设计

基于Delphi语言的数字图像处理实验系统设计刘书杰;周晓峰【摘要】介绍了一种利用Object Pascal面向对象语言Delphi 7.0软件开发平台,并结合Bussiness Skin Form界面控件,实现基本的图像处理,并可以对学生信息的添加、修改、保存、删除、按条件对学生信息进行查询管理的实验系统。
【期刊名称】《长春大学学报》【年(卷),期】2012(022)008【总页数】4页(P945-948)【关键词】数字图像处理;实验系统;Delphi;7.0【作者】刘书杰;周晓峰【作者单位】长春中医药大学附属医院,长春130117【正文语种】中文【中图分类】TP317.4数字图像处理作为一门学科大约形成于20世纪60年代初期。
早期图像处理的目的是改善图像的质量,它以人为对象,以改善人的视觉效果为目的。
随着计算机技术的发展,图像处理技术已经运用到了工业、军事、医学等很多方面。
而图像处理也变成了一个复杂而繁琐的过程,常常一项简单的图像处理过程需要多个图像处理算法共同完成。
如果临时编写算法的话不仅算法的正确性难以保证,而且对于不熟悉编程的人来说是件困难的事。
本文给出一种基于Dlephi语言的数字图像处理系统。
给学生提供一个不受时间地点、实验设备限制的实验环境,还能提供多种算法,对数字图像进行效果的美化加工。
\[11\]数字图像管理实验系统是图像处理实验系统与管理实验系统相结合的数据库应用程序。
根据数字图像处理实验系统的具体实现情况,实验系统的主要功能应包括:\[5\]\[7\](1)登录功能:分教师登录与学生登录;(2)管理功能:教师登录后能管理学生信息,可评分;(3)程序基本功能:打开、关闭、保存、另存为、退出;(4)处理数字图像功能:图像编辑:图像的单步撤销和重做;整幅图的复制,剪切,粘贴,清除;图像调整:位图变换(90度旋转,水平翻转,垂直翻转),取反色,取黑白两色,灰度图变换。
可以用滑动工具条改变参数的有对比度,亮度,饱和度,RGB;图像滤镜:曝光效果,浮雕效果。
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CSDN - 专家门诊 - Delphi 图形处理/多媒体问题推荐 | 保存 | 关闭窗口主题:由Delphi中的图像灰度化代码看基本图像处理~~~作者: ehom (?!)等级:信誉值: 190所属论坛: Delphi 图形处理/多媒体问题点数: 33回复次数: 23发表时间: 2003-02-27 12:48:11Z[基础篇]首先看一段实现24位色图像灰度化转换的代码procedure Grayscale(const Bitmap:TBitmap);varX: Integer;Y: Integer;R,G,B,Gray: Byte;Color: TColor;beginfor Y := 0 to (Bitmap.Height - 1) dobeginfor X := 0 to (Bitmap.Width - 1) dobeginColor := Bitmap.Canvas.Pixels[X,Y];R := Color and $FF;G := (Color and $FF00) shr 8;B := (Color and $FF0000) shr 16;Gray := Trunc(0.3 * R + 0.59 * G + 0.11 * B);Bitmap.Canvas.Pixels[X,Y] := Gray shl 16 or Gray shl 8 or Gray; endendend;{这段代码效率是非常低的,但可以方便我们理解同时一些问题}Delphi的帮助中对TColor已经有了详细的描述,这可以方便我们理解上面的代码!首先看:R := Color and $FF;G := (Color and $FF00) shr 8;B := (Color and $FF0000) shr 16;这是段常见的从TColor中提取三原色的代码,但它是什么意思呢?首先应该知道and是与(.)运算,0.1=0,0.0=0,1.1=1,以取绿色为例:$FF00实际上就是$00FF00,它与一个TColor类型数按位进行与运算后,表示红色和绿色的位都变为了$00,而表示绿色的部分不变(0,1和1进行与运算值都不变),再右移8位,自然就获得了绿色值的8位表示!再获得三原色的值后,就是计算灰度值,0.3 * Red + 0.59 * Green + 0.11 * Blue 这是求加权平均值的公式。
(因为人眼对颜色的敏感度不同,所以权值不同,就像在pf16bit中用了6位表示绿色,其它两种颜色只用了5位,这问题以后另写文章说明)然后就是像素颜色信息的写回,刚才是右移,现在自然就是左移,而或(+)运算就是(0+1=1,0+0=0,1+1=1),举个简单例子就是:($FF shl 16 = $FF0000) or ($FF shl 8 = $FF00) or $FF = $FFFFFF ,其实这里的或运算当然也可以用 + 代替。
虽然上面的代码实现了24位色图像的灰度化,但当图像比较大时,速度非常慢,为什么?查看相关VCL代码可知调用Bitmap.Canvas.Pixels获取,写入像素的颜色信息实际上是利用了API GetPixel、SetPixel,这种方法是非常低效的!(唯一的好处是在进行一些和颜色无关的操作,如图像的旋转,翻转时不需要因为PixelFormat的不同而修改代码)所以应该换一种更高效的访问像素点数据的方法,如用API GetDIBits、SetDIBits,但这种方法比较复杂,好在Delphi3以后版本的TBitmap 中提供了Scanline。
利用Scanline可以快速对像素进行访问!还是以24位色(PixelFormats=pf24bit)为例,可改写为:procedure Grayscale(const Bitmap:TBitmap);constPixelCountMax = 32768;typepRGBTripleArray = ^TRGBTripleArray;TRGBTripleArray = ARRAY[0..PixelCountMax-1] OF TRGBTriple;varRow: pRGBTripleArray;X: Integer;Y: Integer;Gray: Byte;beginfor Y := 0 to (Bitmap.Height - 1) dobeginRow := Bitmap.ScanLine[Y];for X := 0 to (Bitmap.Width - 1) dobeginGray := Trunc(0.3 * Row^[X].rgbtRed + 0.59 * Row^[X].rgbtGreen + 0.11 *Row^[X].rgbtBlue);Row^[X].rgbtRed:=Gray;Row^[X].rgbtGreen:=Gray;Row^[X].rgbtBlue:=Gray;end;end;end;上面的例子用了一个TRGBTriple数组PRGBTriple = ^TRGBTriple;tagRGBTRIPLE = packed recordrgbtBlue: Byte;rgbtGreen: Byte;rgbtRed: Byte;end;TRGBTriple = tagRGBTRIPLE;这种方法会限制位图的大小,但一般不用理会,直接用TBitmap可处理不了那么大的位图当然也可用指针的移动实现,实测结果这样更快~~~procedure Grayscale(const Bitmap:TBitmap);varX: Integer;Y: Integer;PRGB: pRGBTriple;Gray: Byte;beginfor Y := 0 to (Bitmap.Height - 1) dobeginPRGB := Bitmap.ScanLine[Y];for X := 0 to (Bitmap.Width - 1) dobeginGray := Trunc(0.3 * PRGB^.rgbtRed + 0.59 * PRGB^.rgbtGreen + 0.11 * PRGB^.rgbtBlue); PRGB^.rgbtRed:=Gray;PRGB^.rgbtGreen:=Gray;PRGB^.rgbtBlue:=Gray;Inc(PRGB);end;end;end;[颜色篇]在上面提到了,那灰度化代码只能适用于24位色(PixelFormats=pf24bit),为什么?看看记录类型tagRGBTRIPLE,正好24位,所以这样只能处理24位色图!那怎么处理其他的位图呢?先对这各种类型的位图做些简单的介绍~~~pf1bit:每个像素只需要用一位表示,如调色板定义的是黑白两种颜色(0为黑,1为白),这时只能用位操作访问像素信息!如定义var P:PBytefor Y := 0 to (Bitmap.Height - 1) dobeginp := Bitmap.ScanLine[Y];for X := 0 to (Bitmap.width - 1) DIV 8 + 1 dobeginp^:=1 or 2 or 4 or 8 or 16 or 32 or 64 or 128;Inc(PRGB,3);end;end;p^:=1 or 2 or 4 or 8 or 16 or 32 or 64 or 128;这行代码什么意思呢?1=1(二进制),2=10(二进制),4=100(二进制),8=1000(二进制)...结合上篇中解释了的或运算,很容易理解就以八个字位为单位,给其赋上颜色信息!pf4bit:和pf1bit位图一样,操作pf4bit位图也需要用位操作。
pf8bit:可直接利用Byte、TByteArray,但用Scanline取的值表示的只是调色板上颜色的索引。
pf15bit和pf16bit:这两种位图都是16位的,pf15bit是第一位为0,后15位的每5位分别表示红、绿、蓝。
而pf16bit 中绿色占6位,其它两种颜色占用5位(人眼对绿色比较敏感)!pf24bit位图转pf15bit位图代码varRow24:pRGBTriple;Row15:PWord;for j := 0 TO Bitmap.Height-1 DObeginRow15 := Bitmap15.Scanline[j];Row24 := Bitmap24.Scanline[j];for i := 0 TO Bitmap.Width-1 DObeginwith Row24^ doRow15^ := (rgbtRed Shr 3) Shl 10 or (rgbtGreen Shr 3) Shl 5 or (rgbtBlue Shr 3);Inc(Row24);Inc(Row15);endend;pf24bit和pf32bit:pf24bit上面的已多次用到,就不多说了。
而pf32bit和pf24bit一样,用24位(前24位)来记录三原色的颜色信息!PRGBQuad = ^TRGBQuad;tagRGBQUAD = packed recordrgbBlue: Byte;rgbGreen: Byte;rgbRed: Byte;rgbReserved: Byte;end;TRGBQuad = tagRGBQUAD;如果要修改上面的程序,就是简单的PRGBQuad替换PRGBTriple,TRGBQuad替换TRGBTriple的过程~测试表明在pf32bit中利用Scanline处理图像要比pf24bit快。
所以除了单色图(PixelFormats=pf1bit)外(没必要),其它都可转外32位色实现灰度化。
这也是一种比较可行的方法![优化篇]还以上篇中给出的灰度化代码为例procedure Grayscale(const Bitmap:TBitmap);varX: Integer;Y: Integer;PRGB: pRGBTriple;Gray: Byte;beginfor Y := 0 to (Bitmap.Height - 1) dobeginPRGB := Bitmap.ScanLine[Y];for X := 0 to (Bitmap.Width - 1) dobeginGray := Trunc(0.3 * PRGB^.rgbtRed + 0.59 * PRGB^.rgbtGreen + 0.11 * PRGB^.rgbtBlue); PRGB^.rgbtRed:=Gray;PRGB^.rgbtGreen:=Gray;PRGB^.rgbtBlue:=Gray;Inc(PRGB);end;end;end;实际应用中,这种方法已经很快了,但实际上还存在可以优化的余地,什么呢?Gray := Trunc(0.3 * Red + 0.59 * Green + 0.11 * Blue);//这句用的是浮点运算在图像处理中,速度就是生命,能不用浮点运算,就最好不要用!Gray := (30 * Red + 59 * Green + 11 * Blue) div 100;虽然这样一改,运算次数多了一次,但在我的雷鸟1.1G上,处理速度大概能提高5%左右!而同主频下(或略低,如Athlon 1600+相当于P4 1.6G)AMD的CPU浮点运算能力比Intel的较强,整数运算能力较弱,所以用Intel的CPU在这里更能体现出优势!注:x div 100 和 Trunc(x/100)的效果是相同的,但查看其汇编代码可知一个用的指令是div,而另一个是fdiv(即进行浮点运算),还要调用函数Trunc,其处理速度差距非常大,所以能用 x div 100 的时候就不要用 Trunc(x/100)。