先将jpg图象转化为bmp,对bmp图象进行缩小操作,最后转化为jpg<br><br>var<br> jpg :TJpegImage;<br> bmp,tmpbmp :TBitmap;<br>begin<br> jpg :=TJpegImage.Create;<br> jpg.LoadFromFile(.....);<br> bmp :=TBitmap.Create;<br> bmp.Assign(jpg);<br> tmpbmp :=TBitmap.Create;<br> tmpbmp.Width :=bmp.Width div 2;<br> tmpbmp.Height :=bmp.Height div 2;<br> StretchBlt(tmpbmp.Canvas.Handle,0,0,tmpbmp.Width,tmpbmp.Height,<br> bmp.Canvas.Handle,0,0,bmp.Width,bmp.Height,SRCCOPY);<br> jpg.Assign(tmpbmp);<br> jpg.SaveToFile(........);<br> jpg.Free;<br> bmp.Free;<br> tmpbmp.Free;<br>end;