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().
/*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().
/*Define getExtension() ****************************************************************************************************/
function getExtension($file) {
$pos = strrpos($file, '.');
if(!$pos) { $photosubmitted = 'Error: Unknown Filetype'; }
$str = substr($file, $pos, strlen($file));
return $str;
}
The next function allows us to call the proper MIME type, based on image type, in the header of the PHP code get_mime().
/*Define get_mime() ****************************************************************************************************/
function get_mime($var1) {
$t=strtoupper(substr($var1,-4,4));
switch($t){
case ".JPG":
case ".JPEG":
return "image/jpeg";
break;
case ".GIF":
return "image/gif";
break;
case ".PNG":
return "image/png";
break;
default: return "";
break;
}
}This fourth function allows for the use of the proper PHP image createfromxxx call based on image type imagecreatefrom().
/*Define imagecreatefrom() ****************************************************************************************************/
function imagecreatefrom($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 $image;
}Lastly this functions will output the image to the browser image_same_type().
/*Define image_same_type() ****************************************************************************************************/
function image_same_type($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);
}
}Post your thoughts below…
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