PHP 7.1.0 Released

image_type_to_extension

(PHP 5 >= 5.2.0, PHP 7)

image_type_to_extensionObtiene la extensión de un tipo de imagen

Descripción

string image_type_to_extension ( int $imagetype [, bool $include_dot = TRUE ] )

Devuelve la extensión de la constante IMAGETYPE_XXX dada.

Parámetros

imagetype

Una de las constantes IMAGETYPE_XXX.

include_dot

Si le antecede un punto a la extensión. Por defecto es TRUE.

Valores devueltos

Una cadena con la extensión correspondiente al tipo de imagen dado.

Ejemplos

Ejemplo #1 Ejemplo de image_type_to_extension()

<?php
// Crear una instancia de imagen
$im imagecreatetruecolor(100100);

// Guardar imagen
imagepng($im'./prueba' image_type_to_extension(IMAGETYPE_PNG));
imagedestroy($im);
?>

Notas

Nota:

Esta función no requiere la librería GD image.

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User Contributed Notes 5 notes

up
4
Ian Paul Short chukdocsAtHotmailDotCom
10 years ago
To: mail at spybreak dot de

I noted  your solution was for mime_type_to_extension which is flawed because the MIME types to extensions are not unique. See my example to consider what I have observed.

This function performs image type or mime type to extension. With limitation it will not attempt to handle duplicated MIME types. NOT DEFINITIVE!
<?php
   
if(!function_exists('image_type_to_extension')){      

       
$extension;

        function
image_type_or_mime_type_to_extension($image_type, $include_dot) {
           
define ("INVALID_IMAGETYPE", '');
           
           
$extension = INVALID_IMAGETYPE;            /// Default return value for invalid input

           
$image_type_identifiers = array (                                                                ### These values correspond to the IMAGETYPE constants
                   
array (IMAGETYPE_GIF         => 'gif',     "mime_type" => 'image/gif'),                        ###  1 = GIF
                   
array (IMAGETYPE_JPEG        => 'jpg',     "mime_type" => 'image/jpeg'),                        ###  2 = JPG
                   
array (IMAGETYPE_PNG        => 'png',     "mime_type" => 'image/png'),                        ###  3 = PNG
                   
array (IMAGETYPE_SWF        => 'swf',     "mime_type" => 'application/x-shockwave-flash'),    ###  4 = SWF  // A. Duplicated MIME type
                   
array (IMAGETYPE_PSD        => 'psd',     "mime_type" => 'image/psd'),                        ###  5 = PSD
                   
array (IMAGETYPE_BMP        => 'bmp',     "mime_type" => 'image/bmp'),                        ###  6 = BMP
                   
array (IMAGETYPE_TIFF_II    => 'tiff',     "mime_type" => 'image/tiff'),                        ###  7 = TIFF (intel byte order)
                   
array (IMAGETYPE_TIFF_MM    => 'tiff',     "mime_type" => 'image/tiff'),                        ###  8 = TIFF (motorola byte order)
                   
array (IMAGETYPE_JPC        => 'jpc',     "mime_type" => 'application/octet-stream'),            ###  9 = JPC  // B. Duplicated MIME type
                   
array (IMAGETYPE_JP2        => 'jp2',     "mime_type" => 'image/jp2'),                        ### 10 = JP2
                   
array (IMAGETYPE_JPX        => 'jpf',     "mime_type" => 'application/octet-stream'),            ### 11 = JPX  // B. Duplicated MIME type
                   
array (IMAGETYPE_JB2        => 'jb2',     "mime_type" => 'application/octet-stream'),            ### 12 = JB2  // B. Duplicated MIME type           
                   
array (IMAGETYPE_SWC        => 'swc',     "mime_type" => 'application/x-shockwave-flash'),    ### 13 = SWC  // A. Duplicated MIME type
                   
array (IMAGETYPE_IFF        => 'aiff',     "mime_type" => 'image/iff'),                        ### 14 = IFF
                   
array (IMAGETYPE_WBMP        => 'wbmp',     "mime_type" => 'image/vnd.wap.wbmp'),                ### 15 = WBMP
                   
array (IMAGETYPE_XBM        => 'xbm',     "mime_type" => 'image/xbm')                            ### 16 = XBM
           
);                                                                                   
           
            if((
is_int($image_type)) AND (IMAGETYPE_GIF <= $image_type) AND (IMAGETYPE_XBM >= $image_type)){
               
$extension = $image_type_identifiers[$image_type-1]; // -1 because $image_type_identifiers array starts at [0]
               
$extension = $extension[$image_type];
            }
            elseif(
is_string($image_type) AND (($image_type != 'application/x-shockwave-flash') OR ($image_type != 'application/octet-stream'))){               
           
               
$extension match_mime_type_to_extension($image_type, $image_type_identifiers);
            }
            else
            {
               
$extension = INVALID_IMAGETYPE;
            }

               if(
is_bool($include_dot)){

                   if((
false != $include_dot) AND (INVALID_IMAGETYPE != $extension)){
                      
$extension = '.' . $extension;
                   }
               }
               else
               {
                  
$extension = INVALID_IMAGETYPE;
               }                 
      
           return
$extension;

           }
    }   

    function
match_mime_type_to_extension($image_type, $image_type_identifiers){
       
// Return from loop on a match
       
foreach($image_type_identifiers as $_key_outer_loop => $_val_outer_loop){           
            foreach(
$_val_outer_loop as $_key => $_val){
                if(
is_int ($_key)){             // Keep record of extension for mime check
                   
$extension = $_val;
                }
                if(
$_key == 'mime_type'){   
                    if(
$_val === $image_type){    // Found match no need to continue looping
                       
return $extension;        ### Return
                   
}                    
                }
            }
        }
       
// Compared all values without match
       
return $extension = INVALID_IMAGETYPE;   
    }
   
   
$extension = image_type_or_mime_type_to_extension($image_type, $include_dot);
     return
$extension;
}
?>
up
1
bimal at sanjaal dot com
4 years ago
<?php
/**
* Returns a COMMON extension with a dot
*/
function gd_extension($full_path_to_image='')
{
   
$extension = 'null';
    if(
$image_type = exif_imagetype($full_path_to_image))
    {
       
$extension = image_type_to_extension($image_type, false);
    }
   
$known_replacements = array(
       
'jpeg' => 'jpg',
       
'tiff' => 'tif',
    );
   
$extension = '.'.str_replace(array_keys($known_replacements), array_values($known_replacements), $extension);
   
    return
$extension;
}

# Testing
$images = glob('*');
foreach(
$images as $i => $image)
{
   
$extension = gd_extension($image);
    echo
"\r\n", $image, ': ', $extension;
}
?>

Sometimes, the extension is not as I expected, until I wrote this piece.
up
1
aleksandrs dot bogdanovs at gmail dot com
10 years ago
When I was writing a script for my photo website, it was necessary to write such function, which can get the extension of uploaded file (image), so the function is:

<?php
function get_extension($imagetype)
   {
       if(empty(
$imagetype)) return false;
       switch(
$imagetype)
       {
           case
'image/bmp': return '.bmp';
           case
'image/cis-cod': return '.cod';
           case
'image/gif': return '.gif';
           case
'image/ief': return '.ief';
           case
'image/jpeg': return '.jpg';
           case
'image/pipeg': return '.jfif';
           case
'image/tiff': return '.tif';
           case
'image/x-cmu-raster': return '.ras';
           case
'image/x-cmx': return '.cmx';
           case
'image/x-icon': return '.ico';
           case
'image/x-portable-anymap': return '.pnm';
           case
'image/x-portable-bitmap': return '.pbm';
           case
'image/x-portable-graymap': return '.pgm';
           case
'image/x-portable-pixmap': return '.ppm';
           case
'image/x-rgb': return '.rgb';
           case
'image/x-xbitmap': return '.xbm';
           case
'image/x-xpixmap': return '.xpm';
           case
'image/x-xwindowdump': return '.xwd';
           case
'image/png': return '.png';
           case
'image/x-jps': return '.jps';
           case
'image/x-freehand': return '.fh';
           default: return
false;
       }
   }
?>

It's useful for those, who upload files on server.
up
0
Ian Paul Short chukdocsAtHotmailDotCom
10 years ago
2006-09-29

A few notes about some contributions on this page.

1. It seemed to me that on the face it of all of the offerings to emulate "image_type_to_extension" function fell short of the mark in one way or another (See my comments below). That's why I wrote my own and submitted to this page below. In respect of my work any comments, bugs noted or improvements would be gratefully received.

2. Avoid using the Switch statement in an unconventional method to "Break" (I note the use of the return statement!). Also even if it does nothing at the inception of our code - Still put in the default case (It lets others realise that a default is not required or at worst forgotton.

3. In an environment that is under your control the risk of an error by determining the content by its extension or MIME type may seem an attractive solution to a problem. However, in the real world there's no guarantee that a MIME type or file extension is correct for it's associated file.

Consider using functions to get the image type:
      getimagesize or (This is available without GD)
      exif_imagetype

4. There's more to coding than just putting something together to do a job!!! But whatever is done is worthwhile - Hence expletives have no place in this forum!!

5. The idea from "oridan at hotmail dot com" is a very slick idea. I will be taking a closer look at this for my own project.
up
-3
mew at world dot org
8 years ago
There is no need to over complicated folks.

<?php

if ( !function_exists('image_type_to_extension') ) {

    function
image_type_to_extension ($type, $dot = true)
    {
       
$e = array ( 1 => 'gif', 'jpeg', 'png', 'swf', 'psd', 'bmp'
            'tiff'
, 'tiff', 'jpc', 'jp2', 'jpf', 'jb2', 'swc',
           
'aiff', 'wbmp', 'xbm');

       
// We are expecting an integer.
       
$type = (int)$type;
        if (!
$type) {
           
trigger_error( '...come up with an error here...', E_USER_NOTICE );
            return
null;
        }

        if ( !isset(
$e[$type]) ) {
           
trigger_error( '...come up with an error here...' E_USER_NOTICE );
            return
null;
        }

        return (
$dot ? '.' : '') . $e[$type];
    }
   
}

if ( !
function_exists('image_type_to_mime_type') ) {

    function
image_type_to_mime_type ($type)
    {
       
$m = array ( 1 => 'image/gif', 'image/jpeg', 'image/png',
           
'application/x-shockwave-flash', 'image/psd', 'image/bmp',
           
'image/tiff', 'image/tiff', 'application/octet-stream',
           
'image/jp2', 'application/octet-stream', 'application/octet-stream',
           
'application/x-shockwave-flash', 'image/iff', 'image/vnd.wap.wbmp', 'image/xbm');

       
// We are expecting an integer.
       
$type = (int)$type;
        if (!
$type) {
           
trigger_error( '...come up with an error here...', E_USER_NOTICE );
            return
null;
        }

        if ( !isset(
$m[$type]) ) {
           
trigger_error( '...come up with an error here...' E_USER_NOTICE );
            return
null;
        }

        return
$m[$type];
    }

}

?>
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