php man page for exif_imagetype

EXIF_IMAGETYPE(3)							 1							 EXIF_IMAGETYPE(3)

exif_imagetype - Determine the type of an image

SYNOPSIS
       int exif_imagetype (string  $filename)

DESCRIPTION
       exif_imagetype(3) reads the first bytes of an image and checks its signature.

       exif_imagetype(3)   can	 be  used  to  avoid  calls  to  other	exif  functions  with  unsupported  file  types  or  in  conjunction  with
       $_SERVER['HTTP_ACCEPT'] to check whether or not the viewer is able to see a specific image in the browser.

PARAMETERS
	      o $filename
		- The image being checked.

RETURN VALUES
	When a correct signature is found, the appropriate constant value will be returned otherwise the return value is FALSE. The  return  value
       is the same value that getimagesize(3) returns in index 2 but exif_imagetype(3) is much faster.

       Note

	      exif_imagetype(3)  will  emit an E_NOTICE and return FALSE if it is unable to read enough bytes from the file to determine the image
	      type.

CHANGELOG
       +--------+----------------------+
       |Version |		       |
       |	|		       |
       |	|     Description      |
       |	|		       |
       +--------+----------------------+
       | 5.3.0	|		       |
       |	|		       |
       |	|  Added icon support. |
       |	|		       |
       +--------+----------------------+
PREDEFINED CONSTANTS
	The following constants are defined, and represent possible exif_imagetype(3) return values:

       Imagetype Constants

       +------+-----------------------------------------+
       |Value | 					|
       |      | 					|
       |      | 	       Constant 		|
       |      | 					|
       +------+-----------------------------------------+
       |  1   | 					|
       |      | 					|
       |      | 					|
       |      | 	     IMAGETYPE_GIF		|
       |      | 					|
       |  2   | 					|
       |      | 					|
       |      | 					|
       |      | 	    IMAGETYPE_JPEG		|
       |      | 					|
       |  3   | 					|
       |      | 					|
       |      | 					|
       |      | 	     IMAGETYPE_PNG		|
       |      | 					|
       |  4   | 					|
       |      | 					|
       |      | 					|
       |      | 	     IMAGETYPE_SWF		|
       |      | 					|
       |  5   | 					|
       |      | 					|
       |      | 					|
       |      | 	     IMAGETYPE_PSD		|
       |      | 					|
       |  6   | 					|
       |      | 					|
       |      | 					|
       |      | 	     IMAGETYPE_BMP		|
       |      | 					|
       |  7   | 					|
       |      | 					|
       |      | 					|
       |      |  IMAGETYPE_TIFF_II (intel byte order)	|
       |      | 					|
       |  8   | 					|
       |      | 					|
       |      | 					|
       |      | IMAGETYPE_TIFF_MM (motorola byte order) |
       |      | 					|
       |  9   | 					|
       |      | 					|
       |      | 					|
       |      | 	     IMAGETYPE_JPC		|
       |      | 					|
       | 10   | 					|
       |      | 					|
       |      | 					|
       |      | 	     IMAGETYPE_JP2		|
       |      | 					|
       | 11   | 					|
       |      | 					|
       |      | 					|
       |      | 	     IMAGETYPE_JPX		|
       |      | 					|
       | 12   | 					|
       |      | 					|
       |      | 					|
       |      | 	     IMAGETYPE_JB2		|
       |      | 					|
       | 13   | 					|
       |      | 					|
       |      | 					|
       |      | 	     IMAGETYPE_SWC		|
       |      | 					|
       | 14   | 					|
       |      | 					|
       |      | 					|
       |      | 	     IMAGETYPE_IFF		|
       |      | 					|
       | 15   | 					|
       |      | 					|
       |      | 					|
       |      | 	    IMAGETYPE_WBMP		|
       |      | 					|
       | 16   | 					|
       |      | 					|
       |      | 					|
       |      | 	     IMAGETYPE_XBM		|
       |      | 					|
       | 17   | 					|
       |      | 					|
       |      | 					|
       |      | 	     IMAGETYPE_ICO		|
       |      | 					|
       +------+-----------------------------------------+
EXAMPLES
       Example #1

	      exif_imagetype(3) example

	      <?php
	      if (exif_imagetype('image.gif') != IMAGETYPE_GIF) {
		  echo 'The picture is not a gif';
	      }
	      ?>

SEE ALSO
       image_type_to_mime_type(3), getimagesize(3).

PHP Documentation Group 													 EXIF_IMAGETYPE(3)