Exif Funzioni
PHP Manual

exif_imagetype

(PHP 4 >= 4.3.0, PHP 5)

exif_imagetypeDetermine the type of an image

Descrizione

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.

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.

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
5.3.0 Added icon support.
4.3.2 Support for JPC, JP2, JPX, JB2, XBM, and WBMP
4.3.0 Support for SWC

Costanti 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

Esempi

Example #1 exif_imagetype() example

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

Vedere anche:


Exif Funzioni
PHP Manual