PHP 5.4.33 Released

exif_imagetype

(PHP 4 >= 4.3.0, PHP 5)

exif_imagetypeDetermine the type of an image

Descrierea

int exif_imagetype ( string $filename )

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

exif_imagetype() 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.

Parametri

filename
The image being checked.

Valorile întoarse

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() returns in index 2 but exif_imagetype() is much faster.

Notă:

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

Istoria schimbărilor

Versiunea Descriere
5.3.0 Added icon support.

Constante predefinite

The following constants are defined, and represent possible exif_imagetype() 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

Exemple

Example #1 exif_imagetype() example

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

Vedeți de asemenea

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User Contributed Notes 7 notes

up
14
admin at leonard !spam challis dot com
3 years ago
Windows users: If you get the fatal error "Fatal error:  Call to undefined function exif_imagetype()", and you have enabled php_exif.dll, make sure you enable php_mbstring.dll. You must put mbstring before exif in the php.ini, i.e.:

extension=php_mbstring.dll
extension=php_exif.dll

You can check whether this has worked by calling phpinfo() and searching for exif.
up
3
tom dot ghyselinck at telenet dot be
6 years ago
If the function exif_imagetype() is not available,
you can try the following workaround:

if ( ! function_exists( 'exif_imagetype' ) ) {
    function exif_imagetype ( $filename ) {
        if ( ( list($width, $height, $type, $attr) = getimagesize( $filename ) ) !== false ) {
            return $type;
        }
    return false;
    }
}
up
2
christophe dot tournayre at univ*bpclermont dot Fr
1 year ago
Because I only want to check for jpeg or png from a memory string, this is my 2 functions that are quick and don't have any dependencies :

<?php
 
function is_jpeg(&$pict)
  {
    return (
bin2hex($pict[0]) == 'ff' && bin2hex($pict[1]) == 'd8');
  }

  function
is_png(&$pict)
  {
    return (
bin2hex($pict[0]) == '89' && $pict[1] == 'P' && $pict[2] == 'N' && $pict[3] == 'G');
  }
?>
up
1
Tim
6 years ago
By trial and error, it seems that a file has to be 12 bytes or larger in order to avoid a "Read error!".  Here's a work-around to avoid an error being thrown:

// exif_imagetype throws "Read error!" if file is too small
if (filesize($uploadfile) > 11)
    $mimetype = exif_imagetype($uploadfile);
else
    $mimetype = false;
up
-1
Anonymous
7 years ago
Seems to give a 'Read error' warning if the size of the file is very small (2 bytes). I think this is because it needs a min 3 bytes to determine the file type
up
-1
sourabh dot deshmukh at snstech dot com
9 months ago
This functions showing up a warning message that "warnings stream does not support seeking". Is it related to size of file which you mentioned in earlier post or something else. Also how do I get rid of that warning?
up
-1
tom at tomvergote dot be
10 years ago
libexif can also be used to parse image info out of id3 tags:

exif_read_data("mp3_with_2.4ID3TAGS, '', true, false);
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