Summary of various methods for php to determine image formats

The following describes how to determine the image format in php:

The first method is to treat the image path as a string, so the image format is changed to a string for searching for a. Number.

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$ File = "test.jpg "; $ Filetype = strtolower (strrchr ($ file ,".")); $ Arrtype = array (". jpeg", ". bmp", ". gif", ". jpg "); If (! In_array ($ filetype, $ arrtype )) { Echo 'invalid format '; Exit; }

Getimagesize is used to obtain the image size format. This is not a function of the gd class library. This method is very classic. It can be used to determine the image format and obtain the image length and width.

An example is as follows:

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$ Array = getimagesize ("images/flower_1.jpg "); Print_r ($ array );

The return value of this function is an array with the following content:

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Array ( [0] = & gt; 350 [1] => 318. [2] => 2 [3] => width = "350 & Prime; height =" 318 & Prime; [Bits] => 8 [Channels] => 3 [Mime] => image/jpeg )