Delphi常见图象格式转换技术(二)
2006-02-04 13:32:58 来源：WEB开发网Delphi常见图象格式转换技术(二)
作者:lyboy99
e-mail:lyboy99@sina.com
url: http://hnh.126.com
给大家提供几个常用的图象格式转换方法和其转换函数
希望可以对你有帮助
1.TxT 转换为 GIF
2.WMF格式转换为BMP格式
3.BMP格式转换为WMF格式
4.TBitmaps to Windows Regions
-----------------------------------------------------------------------
TxT 转换为 GIF
------------------------------------------------
PRocedure TxtToGif (txt, FileName: String);
var
temp: TBitmap;
GIF : TGIFImage;
begin
temp:=TBitmap.Create;
try
temp.Height :=400;
temp.Width :=60;
temp.Transparent:=True;
temp.Canvas.Brush.Color:=colFondo.ColorValue;
temp.Canvas.Font.Name:=Fuente.FontName;
temp.Canvas.Font.Color:=colFuente.ColorValue;
temp.Canvas.TextOut (10,10,txt);
Imagen.Picture.Assign(nil);
GIF := TGIFImage.Create;
try
GIF.Assign(Temp);
//保存 GIF
GIF.SaveToFile(FileName);
Imagen.Picture.Assign (GIF);
finally
GIF.Free;
end;
Finally
temp.Destroy;
End;
end;
---------------------------------------------------------------------
2.WMF格式转换为BMP格式
--------------------------------------------------------------------
procedure WmfToBmp(FicheroWmf,FicheroBmp:string);
var
MetaFile:TMetafile;
Bmp:TBitmap;
begin
Metafile:=TMetaFile.create;
{Create a Temporal Bitmap}
Bmp:=TBitmap.create;
{Load the Metafile}
MetaFile.LoadFromFile(FicheroWmf);
{Draw the metafile in Bitmap's canvas}
with Bmp do
begin
Height:=Metafile.Height;
Width:=Metafile.Width;
Canvas.Draw(0,0,MetaFile);
{Save the BMP}
SaveToFile(FicheroBmp);
{Free BMP}
Free;
end;
{Free Metafile}
MetaFile.Free;
end;
---------------------------------------------------------------------
3.BMP格式转换为WMF格式
---------------------------------------------------------------------
procedure BmpToWmf (BmpFile,WmfFile:string);
var
MetaFile : TMetaFile;
MFCanvas : TMetaFileCanvas;
BMP : TBitmap;
begin
{Create temps}
MetaFile := TMetaFile.Create;
BMP := TBitmap.create;
BMP.LoadFromFile(BmpFile);
{Igualemos tama?os}
{Equalizing sizes}
MetaFile.Height := BMP.Height;
MetaFile.Width := BMP.Width;
{Create a canvas for the Metafile}
MFCanvas:=TMetafileCanvas.Create(MetaFile, 0);
with MFCanvas do
begin
{Draw the BMP into canvas}
Draw(0, 0, BMP);
{Free the Canvas}
Free;
end;
{Free the BMP}
BMP.Free;
with MetaFile do
begin
{Save the Metafile}
SaveToFile(WmfFile);
{Free it...}
Free;
end;
end;
---------------------------------------------------------------------
4.TBitmaps to Windows Regions
---------------------------------------------------------------------
function BitmapToRegion(bmp: TBitmap; TransparentColor: TColor=clBlack;
RedTol: Byte=1; GreenTol: Byte=1; BlueTol: Byte=1): HRGN;
const
AllocUnit = 100;
type
PRectArray = ^TRectArray;
TRectArray = Array[0..(MaxInt div SizeOf(TRect))-1] of TRect;
var
pr: PRectArray;
h: HRGN;
RgnData: PRgnData;
lr, lg, lb, hr, hg, hb: Byte;
x,y, x0: Integer;
b: PByteArray;
ScanLinePtr: Pointer;
ScanLineInc: Integer;
maxRects: Cardinal;
begin
Result := 0;
{ Keep on hand lowest and highest values for the "transparent" pixels }
lr := GetRValue(TransparentColor);
lg := GetGValue(TransparentColor);
lb := GetBValue(TransparentColor);
hr := Min($ff, lr + RedTol);
hg := Min($ff, lg + GreenTol);
hb := Min($ff, lb + BlueTol);
bmp.PixelFormat := pf32bit;
maxRects := AllocUnit;
GetMem(RgnData,SizeOf(RGNDATAHEADER) + (SizeOf(TRect) * maxRects));
try
with RgnData^.rdh do
begin
dwSize := SizeOf(RGNDATAHEADER);
iType := RDH_RECTANGLES;
nCount := 0;
nRgnSize := 0;
SetRect(rcBound, MAXLONG, MAXLONG, 0, 0);
end;
ScanLinePtr := bmp.ScanLine[0];
ScanLineInc := Integer(bmp.ScanLine[1]) - Integer(ScanLinePtr);
for y := 0 to bmp.Height - 1 do
begin
x := 0;
while x < bmp.Width do
begin
x0 := x;
while x < bmp.Width do
begin
b := @PByteArray(ScanLinePtr)[x*SizeOf(TRGBQuad)];
// BGR-RGB: Windows 32bpp BMPs are made of BGRa quads (not RGBa)
if (b[2] >= lr) and (b[2] <= hr) and
(b[1] >= lg) and (b[1] <= hg) and
(b[0] >= lb) and (b[0] <= hb) then
Break; // pixel is transparent
Inc(x);
end;
{ test to see if we have a non-transparent area in the image }
if x > x0 then
begin
{ increase RgnData by AllocUnit rects if we exceeds maxRects }
if RgnData^.rdh.nCount >= maxRects then
begin
Inc(maxRects,AllocUnit);
ReallocMem(RgnData,SizeOf(RGNDATAHEADER) + (SizeOf(TRect) * MaxRects));
end;
{ Add the rect (x0, y)-(x, y+1) as a new visible area in the region }
pr := @RgnData^.Buffer; // Buffer is an array of rects
with RgnData^.rdh do
begin
SetRect(pr[nCount], x0, y, x, y+1);
{ adjust the bound rectangle of the region if we are "out-of-bounds" }
if x0 < rcBound.Left then rcBound.Left := x0;
if y < rcBound.Top then rcBound.Top := y;
if x > rcBound.Right then rcBound.Right := x;
if y+1 > rcBound.Bottom then rcBound.Bottom := y+1;
Inc(nCount);
end;
end; // if x > x0
if RgnData^.rdh.nCount = 2000 then
begin
h := ExtCreateRegion(nil, SizeOf(RGNDATAHEADER) + (SizeOf(TRect) * maxRects), RgnData^);
if Result > 0 then
begin // Expand the current region
CombineRgn(Result, Result, h, RGN_OR);
DeleteObject(h);
end
else // First region, assign it to Result
Result := h;
RgnData^.rdh.nCount := 0;
SetRect(RgnData^.rdh.rcBound, MAXLONG, MAXLONG, 0, 0);
end;
Inc(x);
end; // scan every sample byte of the image
Inc(Integer(ScanLinePtr), ScanLineInc);
end;
{ need to call ExCreateRegion one more time because we could have left }
{ a RgnData with less than 2000 rects, so it wasn't yet created/combined }
h := ExtCreateRegion(nil, SizeOf(RGNDATAHEADER) + (SizeOf(TRect) * MaxRects), RgnData^);
if Result > 0 then
begin
CombineRgn(Result, Result, h, RGN_OR);
DeleteObject(h);
end
else
Result := h;
finally
FreeMem(RgnData,SizeOf(RGNDATAHEADER) + (SizeOf(TRect) * MaxRects));
end;
----------------------------------------------------------------------------------
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