delphi Jpg和Bitmap相互转换

delphi Jpg和Bitmap互转转换的方法：

uses Jpeg;

procedure Bmp2Jpeg(const BmpFileName, JpgFileName: string);
var
  Bmp: TBitmap;
  Jpg: TJPEGImage;
begin
  Bmp := TBitmap.Create;
  Jpg := TJPEGImage.Create;
  try
    Bmp.LoadFromFile(BmpFileName);
    Jpg.Assign(Bmp);
    Jpg.SaveToFile(JpgFileName);
  finally
    Jpg.Free;
    Bmp.Free;
  end;
end;

procedure Jpeg2Bmp(const BmpFileName, JpgFileName: string);
var
  Bmp: TBitmap;
  Jpg: TJPEGImage;
begin
  Bmp := TBitmap.Create;
  Jpg := TJPEGImage.Create;
  try
    Jpg.LoadFromFile(JpgFileName);
    Bmp.Assign(Jpg);
    Bmp.SaveToFile(BmpFileName);
  finally
    Jpg.Free;
    Bmp.Free;
  end;
end;