Lets define some PHP functions we’ll be calling on for our PHP image tutorial series. We define all these functions in a file named functions.phtml and call it in our PHP code through a PHP include_once(), this way we don’t bother with the functions in our PHP image code.
This first function allows us to determine if the requested image file is an image is_image().
1 2 3 4 5 6 7 | /*Define is_image() ****************************************************************************************************/ function is_image($var1) { $t=strtoupper(substr($var1,-3,3)); $t2=strtoupper(substr($var1,-4,4)); if($t=="GIF" ||$t=="PNG" ||$t=="JPG" ||$t2=="JPEG") return true; return false; } |
This function returns the extension for any file getExtension().
1 2 3 4 5 6 7 | /*Define getExtension() ****************************************************************************************************/ function getExtension($file) { $pos = strrpos($file, '.'); if(!$pos) { $photosubmitted = 'Error: Unknown Filetype'; } $str = substr($file, $pos, strlen($file)); return $str; } |
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The next function allows us to call the proper MIME type, based on image type, in the header of the PHP code get_mime().
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | /*Define get_mime() ****************************************************************************************************/ function get_mime($var1) { $t=strtoupper(substr($var1,-4,4)); switch($t){ case ".JPG": case ".JPEG": return "image/jpeg"; break; case ".GIF": return "image/gif"; break; case ".PNG": return "image/png"; break; default: return ""; break; } } |
This fourth function allows for the use of the proper PHP image createfromxxx() call based on image type imagecreatefrom().
1 2 3 4 5 6 7 8 9 10 11 12 13 | /*Define imagecreatefrom() ****************************************************************************************************/ function imagecreatefrom($file) { if(strtoupper(substr($file,-3,3))=="JPG" || strtoupper(substr($file,-4,4))=="JPEG"){ $image=imagecreatefromjpeg($file); } if(strtoupper(substr($file,-3,3))=="PNG"){ $image=imagecreatefrompng($file); } if(strtoupper(substr($file,-3,3))=="GIF"){ $image=imagecreatefromgif($file); } return $image; } |
Lastly this functions will output the image to the browser image_same_type().
1 2 3 4 5 6 7 8 9 10 11 12 | /*Define image_same_type() ****************************************************************************************************/ function image_same_type($file,$image,$quality = 100) { if(strtoupper(substr($file,-3,3))=="JPG" || strtoupper(substr($file,-4,4))=="JPEG"){ imagejpeg($image,null,$quality); } if(strtoupper(substr($file,-3,3))=="PNG"){ imagepng($image); } if(strtoupper(substr($file,-3,3))=="GIF"){ imagegif($image); } } |
