PHP | exif_imagetype() function

The exif_imagetype() function is an inbuilt function in PHP which is used to determine the type of an image.
Syntax:

int exif_imagetype( string $filename )

Parameters:This function accepts a single parameter $filename which holds the name or URL of the image.
Return Value: This function returns an integer corresponding to one of IMAGETYPE constants as given below: 

• IMAGETYPE_GIF (1)
• IMAGETYPE_JPEG (2)
• IMAGETYPE_PNG (3)
• IMAGETYPE_SWF (4)
• IMAGETYPE_PSD (5)
• IMAGETYPE_BMP (6)
• IMAGETYPE_TIFF_II (7)
• IMAGETYPE_TIFF_MM (8)
• IMAGETYPE_JPC (9)
• IMAGETYPE_JP2 (10)
• IMAGETYPE_JPX (11)
• IMAGETYPE_JB2 (12)
• IMAGETYPE_SWC (13)
• IMAGETYPE_IFF (14)
• IMAGETYPE_WBMP (15)
• IMAGETYPE_XBM (16)
• IMAGETYPE_ICO (17)
• IMAGETYPE_WEBP (18)

Below given programs illustrate the exif_imagetype() function in PHP: 
Program 1: In this example we will check the format of a image file. 

php

<?php
// Load an image from PNG URL
$type = exif_imagetype(
'https://media.geeksforgeeks.org/wp-content/uploads/geeksforgeeks-13.png');

echo $type;
?>

Output:

3 // which corresponds to IMAGETYPE_PNG

Program 2: In this example we will check if a image file is supported or not. 

php

<?php
// Load an image from JPEG URL
$type = exif_imagetype(
'https://media.geeksforgeeks.org/wp-content/uploads/20200123100652/geeksforgeeks12.jpg');

if($type > 0 || $type < 19)
{
    echo 'This is a supported image format.';
}
?>

Output:

This is a supported image format.

Reference: https://www.php.net/manual/en/function.exif-imagetype.php