Declaration

function FindFileFormat(const FileName: WideString; FindMethod: TIEFindFormatMethod = ffContentOnly): TIOFileType;

Description

Returns the file format of the specified file by reading the file and trying to recognize the file header.

FindMethod determines how the file extension is used to aid or confirm format detection:
Some formats cannot be detected by content alone. Sony ARW and Kodak DCR are TIFF internally so will return as ioTIFF. WBMP and Implicit Dicom will return as ioUnknown.

Note: FindFileFormat uses FindStreamFormat to detect the image format. To detect the format using a file name alone, use IEFilenameToFileFormat

Examples

// Determine the file type only by examining the file header/content
if FindFileFormat( sFilename, ffContentOnly ) = ioJPEG then
  ShowMessage( 'File content is JPEG' );

// Determine the file type by examining the file header/content, check it has the correct file extension
if FindFileFormat( sFilename, ffVerifyByExtension ) = ioJPEG then
  ShowMessage( 'File content is JPEG and it has a JPEG extension' );

// Determine the file type by examining the file header/content. If that fails use the correct file extension
if FindFileFormat( sFilename, ffFallbackToExtension ) = ioDICOM then
  ShowMessage( 'File appears to be a DICOM' );

var
  ss: TIOFileType;
begin
  ss := FindFileFormat('C:\myfile.dat', ffContentOnly);
  if ss = ioGIF then
    ImageEnView1.IO.LoadFromFileGIF('C:\myfile.dat')
  else
  if ss = ioJPEG then
    ImageEnView1.IO.LoadFromFileJpeg('C:\myfile.dat');
end;

See Also

◼FindStreamFormat
◼IEFilenameToFileFormat
◼IEExtToFileFormat

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