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    exif_imagetype

    (PHP 4 >= 4.3.0, PHP 5, PHP 7, PHP 8)

    exif_imagetype — Determine the type of an image

    Descrizione

    exif_imagetype(string $filename): int|false

    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.

    Elenco dei parametri

    filename
    The image being checked.

    Valori restituiti

    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.

    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
    18 IMAGETYPE_WEBP
    19 IMAGETYPE_AVIF

    Nota:

    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.

    Log delle modifiche

    Versione Descrizione
    7.1.0 Added WebP support.
    8.1.0 Added AVIF support.

    Esempi

    Example #1 exif_imagetype() example

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

    Vedere anche:

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    User Contributed Notes 7 notes

    up
    22
    Tim
    17 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
    24
    christophe dot tournayre at univ*bpclermont dot Fr
    11 years 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
    15
    admin at leonard !spam challis dot com
    14 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
    11
    tom dot ghyselinck at telenet dot be
    16 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
    -16
    vuatintac at yahoo dot com
    9 years ago
    to checking file is image, I used this:

    function is_image($path)
    {
        $a = getimagesize($path);
        $image_type = $a[2];

        if(in_array($image_type , array(IMAGETYPE_GIF , IMAGETYPE_JPEG ,IMAGETYPE_PNG , IMAGETYPE_BMP)))
        {
            return true;
        }
        return false;
    }
    up
    -19
    Anonymous
    18 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
    -23
    tom at tomvergote dot be
    20 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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