//浮雕
procedure Emboss(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 then
SrcRGB1 := 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) 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 < -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 >= 45) and (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;
procedure Emboss(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
begin
PRGB^.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;
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
begin
if PRGB^.rgbtRed<128 then
PRGB^.rgbtRed :=not PRGB^.rgbtRed ;
if PRGB^.rgbtGreen<128 then
PRGB^.rgbtGreen :=not PRGB^.rgbtGreen;
if PRGB^.rgbtBlue<128 then
PRGB^.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]
else
SrcNextRGB:=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 then IncRGB;
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
procedure Sharpen(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
begin
rowOut := Bmp.ScanLine[i];
Inc(rowOut,Height - j);
rowOut^ := rowIn^;
Inc(rowIn);
end;
end;
Bitmap.Assign(Bmp);
end;
//旋转180度
procedure Rotate180(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[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
function RotateBitmap(Bitmap:TBitmap;Angle:Integer;BackColor:TColor):TBitmap;
var
i,j,iOriginal,jOriginal,CosPoint,SinPoint : integer;
RowOriginal,RowRotated : pRGBTriple;
SinTheta,CosTheta : Extended;
AngleAdd : integer;
begin
Result:=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
begin
SinPoint:=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-1)and
(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
procedure FlipVert(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[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(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
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);
if SrcRGB.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 then
DestRGB.rgbtBlue := Max(128, SrcRGB.rgbtBlue + ValueChange)
else
DestRGB.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
procedure RGBChange(SrcBmp,DestBmp:TBitmap;RedChange,GreenChange,BlueChange:integer);
var
SrcRGB, DestRGB: pRGBTriple;
i,j:integer;
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 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
for X := 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;
理论篇：
关键词：
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。
再说说图像的漫游，当显示的图像超过绘图区时，我们需要对图像进行漫游，以便看到全部的图像。原理是：当鼠标在绘图区进行单击时，这时开始漫游，先记录鼠标的单击位置，然后检测鼠标的移动，根据鼠标和上次的位移计算出“中心点”（需要将屏幕坐标转换为原始图像坐标），根据在上面放大的原理到原始图像中取出要显示的部分，放大显示到绘图区。
算法实现篇：
1.图像放大
变量定义：
PZoom:放大率(整数:100时为100%，根据需要可以将 100 该为 10000 或者更大些，但不推荐使用浮点数)
a,b:中心点
w,h:要截取原始图像的宽和高
x,y:要截取的位置(左上角)
sw,sh:原始图像的宽和高
p1,p2:放大比例
aw,ah:放大后图像的大小
pw,ph:绘图区大小
vx,vy:在绘图区显示的位置（左上角）
vw,vh:在绘图区显示的大小
ptx,pty:临时变量
已知的变量：PZoom,(a,b),(sw,sh),(p1,p2),(aw,ah),(pw,ph)
要计算的变量：(x,y),(w,h),(vx,vy),(vw,vh)
开始计算：
aw=Round(PZoom*sw/100);
ah=Round(PZoom*sh/100);
p1=aw/pw
p2=ah/ph
// 注：Round 用于取整，如其他语言的Int(),Fix()等
if p1>1 then w=Round(sw/p1) else w=sw
if p2>1 then h=Round(sh/p2) else h=sh
// 注：shr 为右移运算符，可以使用“>>1”、“div 2”、“2”或“Round(w/2)”代替
x=a-w shr 1
y=b-h shr 1
// 注：div 为整除运算符
ptx=(w*PZoom) div 100
pty=(h*PZoom) div 100
// 以下计算在绘图区显示的图像大小和位置
变量
Pencent:double; // 缩放比
wx:double; // 宽缩放比
hx:double; // 高缩放比
// 获得缩放比
wx:=pw/ptx
hx:=ph/pty
if wx>hx then Pencent:=hx
else Pencent:=wx;
// 获得图片最后的大小
vw:=Round(Pencent*ptx);
vh:=Round(Pencent*pty);
// 计算出图片的位置
vx:=(pw-vw) div 2;
vy:=(ph-vh) div 2;
// ------------------------------------
好了，两个重要的任务完成(x,y),(w,h),(vx,vy),(vw,vh)已经全部计算得出，下面的工作就是显示了，我们选择 Windows API 进行操作
// 以下显示图像 -----------------------
变量
sDC 为原始图片的设备句柄(DC)
tDC 为临时设备句柄
dDC 最终设备句柄
BitBlt(tDC,0,0,w,h,sDC,0,0,SRCCOPY);
SetStretchBltMode(dDC,STRETCH_DELETESCANS);
StretchBlt(dDC,0,0,vw,vh,tDC,0,0,w,h,SRCCOPY);
最后绘制到显示的区域即可：
例如：BitBlt(GetDC(0),vx,vy,vx+vw,xy+vh,dDC,0,0,SRCCOPY);
// ------------------------------------
2.图像漫游
先定义三个全局变量：
FBeginDragPoint :TPoint; // 记录鼠标开始拖动的位置
FBeginDragSBPoint :TPoint; // 记录“中心点”位置
FBeginDrag :boolean; // 是否已经开始“拖动”
a,b :integer; // “中心点”位置
在鼠标左键点击时，记录鼠标的位置和“中心点”的位置，同时设置 FBeginDrag 为真
当鼠标右键弹起时，设置 FBeginDrag 为假
鼠标移动时，判断 FBeginDrag ，如果为假不进行处理，如果为真进行下面处理：
假设 X,Y 为鼠标当前的位置
a=FBeginDragPoint.X-((X-FBeginDragPoint.X)*100) div PZoom
b=FBeginDragPoint.Y-((Y-FBeginDragPoint.Y)*100) div PZoom
最后使用上面介绍的图像放大显示出图像
技巧篇：
1.如果图像较大，使用 delphi 的 位图对象会出现内存溢出错误，这时可以进行如下设置：
bitImage:=TBitmap.Create;
bitImage.PixelFormat:=pf24bit;
bitImage.ReleaseHandle;
2.如果要让图像自动适应窗口的大小，参考以下代码：
var
p1,p2 :double;
begin
p1:=pw/sw;
p2:=ph/sw;
if p1>p2 then PZoom:=Round(p2*100)
else PZoom:=Round(p1*100);
if PZoom=0 then PZoom:=100;
end;
Delphi灰度图像像素颜色亮度处理
在图像处理中，速度是很重要的。因此，我们得重新处理一下TBitmap,得到TVczhBitmap。这只是因为GetPixels和SetPixels的速度太慢，换一个方法而已。
unit untBitmapProc;
interface
uses Graphics, SysUtils;
type
TVczhBitmap=class(TBitmap)
private
Data:PByteArray;
Line:Integer;
procedure SetFormat;
function GetBytePointer(X,Y:Integer):PByte;
procedure SetBytes(X,Y:Integer;Value:Byte);
function GetBytes(X,Y:Integer):Byte;
protected
published
constructor Create;
public
property Bytes[X,Y:Integer]:Byte read GetBytes write SetBytes;
procedure LoadFromFile(FileName:String);
procedure ToGray;
end;
implementation
procedure TVczhBitmap.SetFormat;
begin
HandleType:=bmDIB;
PixelFormat:=pf24bit;
end;
function TVczhBitmap.GetBytePointer(X,Y:Integer):PByte;
begin
if Line<>Y then
begin
Line:=Y;
Data:=ScanLine[Y];
end;
Longint(result):=Longint(Data)+X;
end;
procedure TVczhBitmap.SetBytes(X,Y:Integer;Value:Byte);
begin
GetBytePointer(X,Y)^:=Value;
end;
function TVczhBitmap.GetBytes(X,Y:Integer):Byte;
begin
result:=GetBytePointer(X,Y)^;
end;
constructor TVczhBitmap.Create;
begin
inherited Create;
SetFormat;
Line:=-1;
end;
procedure TVczhBitmap.LoadFromFile(FileName:String);
begin
inherited LoadFromFile(FileName);
SetFormat;
Line:=-1;
end;
procedure TVczhBitmap.ToGray;
var X,Y,R:Integer;
B:Byte;
begin
for Y:=0 to Height-1 do
for X:=0 to Width-1 do
begin
R:=0;
for B:=0 to 2 do
R:=R+GetBytes(X*3+B,Y);
for B:=0 to 2 do
SetBytes(X*3+B,Y,R div 3);
end;
end;
end.
此后，我们需要建立几个窗体。第一个用来显示图片，第二个用来处理图片，其他的窗体都继承自第二个窗体，包含实际的处理方法。
先看第二个窗口：
unit untProc;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, ExtCtrls, untBitmapProc, StdCtrls, ComCtrls;
type
TfrmProcessor = class(TForm)
pbBar: TPaintBox;
gpProc: TGroupBox;
Button1: TButton;
procedure FormCreate(Sender: TObject);
procedure FormDestroy(Sender: TObject);
procedure FormShow(Sender: TObject);
procedure pbBarPaint(Sender: TObject);
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
BarData:array[0..255]of Byte;
Bar:TVczhBitmap;
procedure DrawBar;
end;
var
frmProcessor: TfrmProcessor;
implementation
{$R *.dfm}
uses untViewer;
procedure TfrmProcessor.DrawBar;
var I:Integer;
begin
Bar.Canvas.FillRect(Bar.Canvas.ClipRect);
Bar.Canvas.MoveTo(0,255-BarData[0]);
for I:=1 to 255 do
Bar.Canvas.LineTo(I,255-BarData[I]);
end;
procedure TfrmProcessor.FormCreate(Sender: TObject);
begin
Bar:=TVczhBitmap.Create;
Bar.Width:=256;
Bar.Height:=256;
Bar.Canvas.Brush.Color:=clWhite;
Bar.Canvas.Brush.Style:=bsSolid;
end;
procedure TfrmProcessor.FormDestroy(Sender: TObject);
begin
Bar.Free;
end;
procedure TfrmProcessor.FormShow(Sender: TObject);
var I:Integer;
begin
for I:=0 to 255 do
BarData[I]:=I;
DrawBar;
end;
procedure TfrmProcessor.pbBarPaint(Sender: TObject);
begin
pbBar.Canvas.Draw(0,0,Bar);
end;
procedure TfrmProcessor.Button1Click(Sender: TObject);
var X,Y:Integer;
begin
for Y:=0 to Buffer.Height-1 do
for X:=0 to Buffer.Width*3-1 do
Played.Bytes[X,Y]:=BarData[Buffer.Bytes[X,Y]];
frmViewer.FormPaint(frmViewer);
end;
end.
之后，做一个窗口继承自它，则调整BarData[]后，按Apply即可看到结果。
现在开始将图像处理。具体效果见示例程序。
一、颜色反转。
灰度图像的颜色都是从0~255，所以，为了使颜色反转，我们可以用255减去该颜色值以得到反转后的颜色。
var I:Integer;
begin
inherited;
for I:=0 to 255 do
BarData[I]:=255-I;//用255减去该颜色值
DrawBar;
pbBarPaint(pbBar);
end;
二、缩小颜色范围以增强或减弱亮度
颜色本来是从0~255的。如果调节它的范围，例如从0~16，则会是图像明显变暗。我们可以把起始值设为a，把终止值设为b，则新的颜色值New=a+(b-1)*Old/255。这样做的话可以改变亮度，并且不会破坏原先颜色的顺序。代码如下
var I:Integer;
begin
for I:=0 to 255 do
BarData[I]:=(255-sbMin.Position)+Round((sbMin.Position-sbMax.Position)/255*I);
DrawBar;
pbBarPaint(pbBar);
Button1Click(Button1);
end;
这里的sbMin.Position和sbMaxPosition都是反转过的。所以使用时要用255去减
三、增加某个范围内的颜色范围
如果图像本身的颜色范围很小的画，你可以通过这种方法来加大图像的对比度，有利于对图像的分析。具体做法：
选取一个值a做为起始值，选取一个值b做为终止值，然后按以下公式变形：
| 0 (X<=a)
f(X)= | 255/(b-a)*(X-a)
| 255(X>=b)
var I:Integer;
begin
for I:=0 to 255 do
begin
if I<=sbMin.Position then
BarData[I]:=0
else if I>=sbMax.Position then
BarData[I]:=255
else
BarData[I]:=Round(255/(sbMax.Position-sbMin.Position)*(I-sbMin.Position));
end;
DrawBar;
pbBarPaint(pbBar);
Button1Click(Button1);
end;
四、变为黑白图片
在使用第三个功能的时候，你会发现当b<=a时，图像上的颜色除了黑色就是白色。这样操作的好处是不能直接显示出来的。这只要到了比较高级的图像处理如边缘检测等，才有作用。本例可以拿第三种方法的公式再变形，因此不作详细阐述。
五、指数级亮度调整
我们假设这个图的定义域是[0,1]，值域也是[0,1]。那么，定义函数f(x)=x^c，则f(x)的图像有一段如上图。我们再用鼠标操作时，可以在上面取一点P(a,b)，然后使f(x)通过点P，则c=ln(b)/ln(a)。有了c之后，我们就可以对颜色进行操作了：
New=(Old/255)^c*255=exp(ln(old/255)*c)*255
var ea,eb,ec:Extended;
I:Integer;
begin
ea:=A/255;
eb:=B/255;
ec:=Ln(eb)/Ln(ea);
for I:=1 to 255 do
BarData[I]:=Round(Exp(Ln((I/255))*ec)*255);
DrawBar;
pbBarPaint(pbBar);
Button1Click(Button1);
end;
这样做可以调节图像的亮度。
Delphi图形显示特效的技巧
概述
----目前在许多学习软件、游戏光盘中，经常会看到各种
图形显示技巧，凭着图形的移动、交错、雨滴状、百页窗、积木堆叠等显现方式，使画面变得更为生动活泼，更 能吸引观众。本文将探讨如何在delphi中实现各种图形显示技巧。
基本原理
----在delphi中，实现一副图象的显示是非常简单的，只要在form中定义一个timage组件，设置其picture属性，然后选 择任何有效的.ico、.bmp、.emf或.wmf文件，进行load，所选文 件就显示在timage组件中了。但这只是直接将图形显示在窗体中，毫无技巧可言。为了使图形显示具有别具一格的效果，可以按下列步骤实现：
----定义一个timage组件，把要显示的图形先装入到timage组件中，也就是说，把图形内容从磁盘载入内存中， 做为图形缓存。
----创建一新的位图对象，其尺寸跟timage组件中的图形一样。
----利用画布(canvas)的copyrect功能(将一个画布的矩形区域拷贝到另一个画布的矩形区域)，使用技巧，动态形
成位图文件内容，然后在窗体中显示位图。
----实现方法
下面介绍各种图形显示技巧：
1.推拉效果
将要显示的图形由上、下、左、右方向拉进屏幕内显示，同时将屏幕上原来的旧图盖掉，此种效果可分为四
种，上拉、下拉、左拉、右拉，但原理都差不多，以上拉 效果为例。
原理：首先将放在暂存图形的第一条水平线，搬移至要显示的位图的最后一条，接着再将暂存图形的前两条水平线，依序搬移至要显示位图的最后两条水平线，然后搬移前三条、前四条叄?直到全部图形数据搬完为止。在搬移的过程中即可看到显示的位图由下而上浮起，而达到上拉的效果。
程序算法：
procedure tform1.button1click(sender: tobject);
var
newbmp: tbitmap;
i,bmpheight,bmpinteger;
begin
newbmp:= tbitmap.create;
newbmp.=image1.width;
newbmp.height:=image1.height;
bmpheight:=image1.height;
bmp=image1.width;
for i:=0 to bmpheight do
begin
newbmp.canvas.copyrect(rect
(0,bmpheight-i,bmpwidth,bmpheight),
image1.canvas,
rect(0,0,bmpwidth,i));
form1.canvas.draw(120,100,newbmp);
end;
newbmp.free;
end;
2.垂直交错效果
原理：将要显示的图形拆成两部分，奇数条扫描线由上往下搬移，偶数条扫描线的部分则由下往上搬移，而且两者同时进行。从屏幕上便可看到分别由上下两端出现的较淡图形向屏幕中央移动，直到完全清楚为止。
程序算法：
procedure tform1.button4click(sender: tobject);
var
newbmp:tbitmap;
i,j,bmpheight,bmpinteger;
begin
newbmp:= tbitmap.create;
newbmp.=image1.width;
newbmp.height:=image1.height;
bmpheight:=image1.height;
bmp=image1.width;
i:=0;
while i< =bmpheight do
begin
j:=i;
while j >0 do
begin
newbmp.canvas.copyrect(rect(0,j-1,bmpwidth,j),
image1.canvas,
rect(0,bmpheight-i+j-1,bmpwidth,bmpheight-i+j));
newbmp.canvas.copyrect(rect
(0,bmpheight-j,bmpwidth,bmpheight-j+1),
image1.canvas,
rect(0,i-j,bmpwidth,i-j+1));
j:=j-2;
end;
form1.canvas.draw(120,100,newbmp);
i:=i+2;
end;
newbmp.free;
end;
3.水平交错效果
原理：同垂直交错效果原理一样，只是将分成两组后的图形分别由左右两端移进屏幕。
程序算法：
procedure tform1.button5click(sender: tobject);
var
newbmp:tbitmap;
i,j,bmpheight,bmpinteger;
begin
newbmp:= tbitmap.create;
newbmp.=image1.width;
newbmp.height:=image1.height;
bmpheight:=image1.height;
bmp=image1.width;
i:=0;
while i< =bmpwidth do
begin
j:=i;
while j >0 do
begin
newbmp.canvas.copyrect(rect(j-1,0,j,bmpheight),
image1.canvas,
rect(bmpwidth-i+j-1,0,bmpwidth-i+j,bmpheight));
newbmp.canvas.copyrect(rect
(bmpwidth-j,0,bmpwidth-j+1,bmpheight),
image1.canvas,
rect(i-j,0,i-j+1,bmpheight));
j:=j-2;
end;
form1.canvas.draw(120,100,newbmp);
i:=i+2;
end;
newbmp.free;
end;
4.雨滴效果
原理：将暂存图形的最后一条扫描线，依序搬移到可视位图的第一条到最后一条扫描线，让此条扫描线在屏幕上留下它的轨迹。接着再把暂存图形的倒数第二条扫描线，依序搬移到可视位图的第一条到倒数第二条扫描线。其余的扫描线依此类推。
程序算法：
procedure tform1.button3click(sender: tobject);
var
newbmp:tbitmap;
i,j,bmpheight,bmpinteger;
begin
newbmp:= tbitmap.create;
newbmp.=image1.width;
newbmp.height:=image1.height;
bmpheight:=image1.height;
bmp=image1.width;
for i:=bmpheight downto 1 do
for j:=1 to i do
begin
newbmp.canvas.copyrect(rect(0,j-1,bmpwidth,j),
image1.canvas,
rect(0,i-1,bmpwidth,i));
form1.canvas.draw(120,100,newbmp);
end;
newbmp.free;
end;
5.百叶窗效果
原理：将放在暂存图形的数据分成若干组，然后依次从第一组到最后一组搬移，第一次每组各搬移第一条扫描线到可视位图的相应位置，第二次搬移第二条扫描线，接着搬移第三条、第四条扫描线.
程序算法：
procedure tform1.button6click(sender: tobject);
var
newbmp:tbitmap;
i,j,bmpheight,bmpinteger;
xgroup,xcount:integer;
begin
newbmp:= tbitmap.create;
newbmp.=image1.width;
newbmp.height:=image1.height;
bmpheight:=image1.height;
bmp=image1.width;
xgroup:=16;
xcount:=bmpheight div xgroup;
for i:=0 to xcount do
for j:=0 to xgroup do
begin
newbmp.canvas.copyrect(rect
(0,xcount*j+i-1,bmpwidth,xcount*j+i),
image1.canvas,
rect(0,xcount*j+i-1,bmpwidth,xcount*j+i));
form1.canvas.draw(120,100,newbmp);
end;
newbmp.free;
end;
6.积木效果
原理：是雨滴效果的一种变化，不同之处在于，积木效果每次搬移的是一块图形，而不只是一根扫描线。
程序算法：
procedure tform1.button7click(sender: tobject);
var
newbmp:tbitmap;
i,j,bmpheight,bmpinteger;
begin
newbmp:= tbitmap.create;
newbmp.=image1.width;
newbmp.height:=image1.height;
bmpheight:=image1.height;
bmp=image1.width;
i:=bmpheight;
while i>0 do
begin
for j:=10 to i do
begin
newbmp.canvas.copyrect(rect(0,j-10,bmpwidth,j),
image1.canvas,
rect(0,i-10,bmpwidth,i));
form1.canvas.draw(120,100,newbmp);
end;
i:=i-10;
end;
newbmp.free;
end;
结束语
上述图形显示效果均已上机通过。使用效果很好。
用Delphi实现图像放大镜
向窗体上添加两个TImage组件，其中一个TImage组件的Name属性设置为Image1，它充当原图片显示的载体。另一个TImage组件的Name属性设置为Image2，它可以显示放大后的图像。添加组件后的窗体如图1所示。
图1 添加组件后的窗体
本例的核心是StretchBlt函数，利用StretchBlt函数实现局部图像放大，响应代码如下：
procedure TForm1.Image1MouseMove(Sender: TObject; Shift: TShiftState; X, Y: Integer);
begin
StretchBlt(Image2.Canvas.Handle,0,0,Image2.Width,Image2.Height,
Image1.Canvas.Handle, X-20,Y-20,40,40,SRCCOPY);
Image2.Refresh;
Screen.Cursors[1]:=LoadCursorFromFile(’MAGNIFY.CUR’);
Self.Cursor:=1;
end;
程序首先会调用StretchBlt函数，以鼠标当前位置作为中心点，以边长为40选中Image1组件上的局部图像，并放大此局部图像到Image2组件上。然后通过调用Image2组件的Refresh方法以刷新Image2组件的显示。最后设置鼠标指针为新的形状。
程序代码如下：
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, ExtCtrls, StdCtrls;
type
TForm1 = class(TForm)
Image1: TImage;
Image2: TImage;
procedure Image1MouseMove(Sender: TObject; Shift: TShiftState; X,Y: Integer);
procedure FormMouseMove(Sender: TObject; Shift: TShiftState; X,Y: Integer);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
procedure TForm1.Image1MouseMove(Sender:TObject;Shift:TShiftState;X,Y: Integer);
begin
StretchBlt(Image2.Canvas.Handle,0,0,Image2.Width,Image2.Height,Image1.Canvas.Handle, X-20,Y-20,40,40,SRCCOPY);
Image2.Refresh;
Screen.Cursors[1]:=LoadCursorFromFile(’MAGNIFY.CUR’);
Self.Cursor:=1;
end;
procedure TForm1.FormMouseMove(Sender: TObject; Shift: TShiftState; X,Y: Integer);
begin
Screen.Cursors[1]:=crDefault;
Self.Cursor:=1;
end;
end.
保存文件，然后按F9键运行程序，程序运行结果如图2所示。
图2 程序运行结果
放大图像是一个优秀的看图软件必备的功能，本实例提供了一种非常简便易行的方法，不但代码数量少，而且执行效率高。