图片格式转化的问题

[taoran12]

delphi中怎么在不知道源图片是什么格式的情况下 将其转化为另一种格式比如 bitmap

[dinoalex]

TImage或TBitmap或其它第三方(png,gif),A(jpg)导入后,B(bitmap)生成,然后load或assign,最后save,就行了

[Frank.WU]

每一种图片都有自己的独特格式的：

function ImageMIMEType(Source: string): string; 
var 
  Mem: TMemoryStream; 
  Buffer: Word; 
  i: integer; 
const 
  IMG_CLASS_UNKNOWN = 'unknown'; 
  IMG_CLASS_ERROR = 'error'; 
  IMG_CLASS_JPEG = 'image/jpeg'; 
  IMG_CLASS_BITMAP = 'image/bmp'; 
  IMG_CLASS_GIF = 'image/gif'; 
  IMG_CLASS_PNG = 'image/png'; 
  IMG_CLASS_PCX = 'image/pcx'; 
  IMG_CLASS_PSD = 'image/psd'; 
  IMG_CLASS_RAS = 'image/ras'; 
  IMG_CLASS_SGI = 'image/sgi'; 
  IMG_CLASS_TIFF = 'image/tiff'; 
 
begin 
  Mem := TMemoryStream.Create; 
 
  try 
    Mem.LoadFromFile(Source); 
    Mem.Position := 0; 
    if Mem.Size = 0 then 
    begin 
       //错误 
      Result := IMG_CLASS_ERROR; 
      Exit; 
    end; 
 
    Mem.ReadBuffer(Buffer, 2); 
 
    if Buffer = $4D42 then 
      Result := IMG_CLASS_BITMAP 
    else 
      if Buffer = $D8FF then 
        Result := IMG_CLASS_JPEG 
      else 
        if Buffer = $4947 then 
          Result := IMG_CLASS_GIF 
        else 
          if Buffer = $050A then 
            Result := IMG_CLASS_PCX 
          else 
            if Buffer = $5089 then 
              Result := IMG_CLASS_PNG 
            else 
              if Buffer = $4238 then 
                Result := IMG_CLASS_PSD 
              else 
                if Buffer = $A659 then 
                  Result := IMG_CLASS_RAS 
                else 
                  if Buffer = $DA01 then 
                    Result := IMG_CLASS_SGI 
                  else 
                    if Buffer = $4949 then 
                      Result := IMG_CLASS_TIFF 
                    else 
                      Result := IMG_CLASS_UNKNOWN; 
 
 
  finally 
 
    Mem.Free; //释放内存流对象 
 
  end; 
end;

[lyhoo163]

[Quote=引用 2 楼 sailxia 的回复:]
每一种图片都有自己的独特格式的：

Delphi(Pascal) code
function ImageMIMEType(Source: string): string;
var
Mem: TMemoryStream;
Buffer: Word;
i: integer;
const
IMG_CLASS_UNKNOWN = 'unknown';
……
[/Quote]

帮顶。。。

[无条件为你]

不知道格式的话可以直接载入到GDI+中显示，然后转换。加上容错处理就可以了。主要是防止非识别格式的文件。比如你将一个EXE换掉扩展名来转。