The getimagesizefromstring() function is an inbuilt function in PHP which is used to get the size of an image from a string. This function accepts the image data as a string parameter and determines the image size and returns the dimensions with the file type and height/width of the image.
Syntax:
array getimagesizefromstring( $imagedata, &$imageinfo )
Parameters: This function accepts two parameters as mentioned above and described below:
- $filename: It is a mandatory parameter which accepts image data as a string.
 - $imageinfo: It is an optional parameter which allows to extract some extended information from the image file such as the different JPG APP markers as associative array.
 
Return Value: This function returns the dimensions along with the file type and the height/width text string.
Below programs illustrate the getimagesizefromstring() function in PHP:
Image:
Example 1 :
<?php   $img =     // Open image as a string $data = file_get_contents($img);    // getimagesizefromstring function accepts image data as string $info = getimagesizefromstring($data);   // Display the image content var_dump($info); ?>  | 
Output:
array(6) { 
    [0]=> int(667) 
    [1]=> int(184) 
    [2]=> int(3) 
    [3]=> string(24) "width="667" height="184"" 
    ["bits"]=> int(8) 
    ["mime"]=> string(9) "image/png" 
} 
Example 2:
<?php $img =     // Open image as a string $data = file_get_contents($img);   // getimagesizefromstring function accepts image data as string list($width, $height, $type, $attr) = getimagesizefromstring($data);    // Displaying dimensions of the image  echo "Width of image: " . $width . "<br>";       echo "Height of image: " . $height . "<br>";       echo "Image type: " . $type . "<br>";       echo "Image attribute: " . $attr;  ?>  | 
Output:
Width of image: 667 Height of image: 184 Image type: 3 Image attribute: width="667" height="184"
Reference: http://php.net/manual/en/function.getimagesizefromstring.php

                                    