基本图象处理代码(2)

[亮度、对比度、饱和度的调整]

//亮度调整
procedure BrightnessChange(const SrcBmp,DestBmp:TBitmap;ValueChange:integer);
var
  i, j: integer;
  SrcRGB, DestRGB: pRGBTriple;
  Table: array[0..255]of Byte;
begin
  if ValueChange > 0 then
    for i := 0 to 255 do
      Table[i]:=Byte(i + ((ValueChange * (i xor 255)) shr 8))
  else
    for i := 0 to 255 do
      Table[i]:=Byte(i - ((Abs(ValueChange) * i) shr 8));
  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
      DestRGB^.rgbtRed := Table[SrcRGB^.rgbtRed];
      DestRGB^.rgbtGreen := Table[SrcRGB^.rgbtGreen];
      DestRGB^.rgbtBlue := Table[SrcRGB^.rgbtBlue];
      Inc(SrcRGB);
      Inc(DestRGB);
    end;
  end;
end;

//对比度调整
procedure ContrastChange(const SrcBmp,DestBmp:TBitmap;ValueChange:integer);
var
  i, j: integer;
  SrcRow, DestRow: pRGBTriple;
begin
  for i := 0 to SrcBmp.Height - 1 do
  begin
    SrcRow := SrcBmp.ScanLine[i];
    DestRow := DestBmp.ScanLine[i];
    for j := 0 to SrcBmp.Width - 1 do
    begin
      if ValueChange>=0 then
      begin
      if SrcRow.rgbtRed >= 128 then
        DestRow.rgbtRed := Min(255, SrcRow.rgbtRed + (Abs(128 - SrcRow.rgbtRed) * ValueChange) div 128)
      else
        DestRow.rgbtRed := Max(0, SrcRow.rgbtRed - (Abs(128 - SrcRow.rgbtRed) * ValueChange) div 128);
      if SrcRow.rgbtGreen >= 128 then
        DestRow.rgbtGreen := Min(255, SrcRow.rgbtGreen + (Abs(128 - SrcRow.rgbtGreen) * ValueChange) div 128)
      else
        DestRow.rgbtGreen := Max(0, SrcRow.rgbtGreen - (Abs(128 - SrcRow.rgbtGreen) * ValueChange) div 128);
      if SrcRow.rgbtBlue >= 128 then
        DestRow.rgbtBlue := Min(255, SrcRow.rgbtBlue + (Abs(128 - SrcRow.rgbtBlue) * ValueChange) div 128)
      else
        DestRow.rgbtBlue := Max(0, SrcRow.rgbtBlue - (Abs(128 - SrcRow.rgbtBlue) * ValueChange) div 128);
      end
      else
      begin
      if SrcRow.rgbtRed >= 128 then
        DestRow.rgbtRed := Max(128, SrcRow.rgbtRed + (Abs(128 - SrcRow.rgbtRed) * ValueChange) div 128)
      else
        DestRow.rgbtRed := Min(128, SrcRow.rgbtRed - (Abs(128 - SrcRow.rgbtRed) * ValueChange) div 128);
      if SrcRow.rgbtGreen >= 128 then
        DestRow.rgbtGreen := Max(128, SrcRow.rgbtGreen + (Abs(128 - SrcRow.rgbtGreen) * ValueChange) div 128)
      else
        DestRow.rgbtGreen := Min(128, SrcRow.rgbtGreen - (Abs(128 - SrcRow.rgbtGreen) * ValueChange) div 128);
      if SrcRow.rgbtBlue >= 128 then
        DestRow.rgbtBlue := Max(128, SrcRow.rgbtBlue + (Abs(128 - SrcRow.rgbtBlue) * ValueChange) div 128)
      else
        DestRow.rgbtBlue := Min(128, SrcRow.rgbtBlue - (Abs(128 - SrcRow.rgbtBlue) * ValueChange) div 128);
      end;
      Inc(SrcRow);
      Inc(DestRow);
    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;

如果有些图像处理的基础，这些代码都比较好理解，主要是三原色的值不要超过(0-255)的范围，有些朋友没有注意这问题，当超过范围后，会出现些难看的“色斑”！

[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;

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