Compress and RESCALE uploaded image - php

Question

I have a function that uploads files up to 8MB but now I also want to compress or at least rescale larger images, so my output image won't be any bigger than 100-200 KB and 1000x1000px resolution. How can I implement compress and rescale (proportional) in my function?
function uploadFile($file, $file_restrictions = '', $user_id, $sub_folder = '') {
global $path_app;
$new_file_name = generateRandomString(20);
if($sub_folder != '') {
if(!file_exists('media/'.$user_id.'/'.$sub_folder.'/')) {
mkdir('media/'.$user_id.'/'.$sub_folder, 0777);
}
$sub_folder = $sub_folder.'/';
}
else {
$sub_folder = '';
}
$uploadDir = 'media/'.$user_id.'/'.$sub_folder;
$uploadDirO = 'media/'.$user_id.'/'.$sub_folder;
$finalDir = $path_app.'/media/'.$user_id.'/'.$sub_folder;
$fileExt = explode(".", basename($file['name']));
$uploadExt = $fileExt[count($fileExt) - 1];
$uploadName = $new_file_name.'_cache.'.$uploadExt;
$uploadDir = $uploadDir.$uploadName;
$restriction_ok = true;
if(!empty($file_restrictions)) {
if(strpos($file_restrictions, $uploadExt) === false) {
$restriction_ok = false;
}
}
if($restriction_ok == false) {
return '';
}
else {
if(move_uploaded_file($file['tmp_name'], $uploadDir)) {
$image_info = getimagesize($uploadDir);
$image_width = $image_info[0];
$image_height = $image_info[1];
if($file['size'] > 8000000) {
unlink($uploadDir);
return '';
}
else {
$finalUploadName = $new_file_name.'.'.$uploadExt;
rename($uploadDirO.$uploadName, $uploadDirO.$finalUploadName);
return $finalDir.$finalUploadName;
}
}
else {
return '';
}
}
}

Answer 1

For the rescaling I use a function like this:
function dimensions($width,$height,$maxWidth,$maxHeight)
// given maximum dimensions this tries to fill that as best as possible
{
// get new sizes
if ($width > $maxWidth) {
$height = Round($maxWidth*$height/$width);
$width = $maxWidth;
}
if ($height > $maxHeight) {
$width = Round($maxHeight*$width/$height);
$height = $maxHeight;
}
// return array with new size
return array('width' => $width,'height' => $height);
}
The compression is done by a PHP function:
// set limits
$maxWidth = 1000;
$maxHeight = 1000;
// read source
$source = imagecreatefromjpeg($originalImageFile);
// get the possible dimensions of destination and extract
$dims = dimensions(imagesx($source),imagesy($source),$maxWidth,$maxHeight);
// prepare destination
$dest = imagecreatetruecolor($dims['width'],$dims['height']);
// copy in high-quality
imagecopyresampled($dest,$source,0,0,0,0,
$width,$height,imagesx($source),imagesy($source));
// save file
imagejpeg($dest,$destinationImageFile,85);
// clear both copies from memory
imagedestroy($source);
imagedestroy($dest);
You will have to supply $originalImageFile and $destinationImageFile. This stuff comes from a class I use, so I edited it quite a lot, but the basic functionality is there. I left out any error checking, so you still need to add that. Note that the 85 in imagejpeg() denotes the amount of compression.

Answer 2

you can use a simple one line solution through imagemagic library the command will like this
$image="path to image";
$res="option to resize"; i.e 25% small , 50% small or anything else
exec("convert ".$image." -resize ".$res." ".$image);
with this you can rotate resize and many other image customization

Answer 3

Take a look on imagecopyresampled(), There is also a example that how to implement it, For compression take a look on imagejpeg() the third parameter helps to set quality of the image, 100 means (best quality, biggest file) and if you skip the last option then default quality is 75 which is good and compress it.