Crop from the center and resize in PHP - php

Question

I want to have a function that resizes to a specific height en weight of an image without losing the aspect ratio. So first i want to crop it and then resizing it.
This is what i got so far:
function image_resize($src, $dst, $width, $height, $crop=1){
if(!list($w, $h) = getimagesize($src)) return "Unsupported picture type!";
$type = strtolower(substr(strrchr($src,"."),1));
if($type == 'jpeg') $type = 'jpg';
switch($type){
case 'bmp': $img = imagecreatefromwbmp($src); break;
case 'gif': $img = imagecreatefromgif($src); break;
case 'jpg': $img = imagecreatefromjpeg($src); break;
case 'png': $img = imagecreatefrompng($src); break;
default : return "Unsupported picture type!";
}
// resize
if($crop){
if($w < $width or $h < $height) return "Picture is too small!";
$ratio = max($width/$w, $height/$h);
$h = $height / $ratio;
$x = ($w - $width / $ratio) / 2;
$w = $width / $ratio;
}
else{
if($w < $width and $h < $height) return "Picture is too small!";
$ratio = min($width/$w, $height/$h);
$width = $w * $ratio;
$height = $h * $ratio;
$x = 0;
}
$new = imagecreatetruecolor($width, $height);
// preserve transparency
if($type == "gif" or $type == "png"){
imagecolortransparent($new, imagecolorallocatealpha($new, 0, 0, 0, 127));
imagealphablending($new, false);
imagesavealpha($new, true);
}
imagecopyresampled($new, $img, 0, 0, $x, 0, $width, $height, $w, $h);
switch($type){
case 'bmp': imagewbmp($new, $dst); break;
case 'gif': imagegif($new, $dst); break;
case 'jpg': imagejpeg($new, $dst); break;
case 'png': imagepng($new, $dst); break;
}
return true;
}
The function is working fine, but its crops from the upper leftcorner.
I want it to crop from the center.

Answer 1

You have to calculate cropped image shift for imagecopyresampled():
Keep original size before you calculate new:
// resize
$originalW = $w;
$originalH = $h;
if ($crop) {
...
And replace Your imagecopyresampled by this:
imagecopyresampled($new, $img, 0, 0, ($originalW - $width)/2, ($originalH - $height)/2, $width, $height, $w, $h);
You can check manual here.

Answer 2

I solve the black areas in the image. Now this script resize, crop and center.
The final code is here:
if(!list($w, $h) = getimagesize($src)) return array(false,"Unsupported picture type!");
$type = strtolower(substr(strrchr($src,"."),1));
if($type == 'jpeg') $type = 'jpg';
switch($type){
case 'bmp': $img = imagecreatefromwbmp($src); break;
case 'gif': $img = imagecreatefromgif($src); break;
case 'jpg': $img = imagecreatefromjpeg($src); break;
case 'png': $img = imagecreatefrompng($src); break;
default : return array(false,"Unsupported picture type!");
}
// resize
$originalW = $w;
$originalH = $h;
if($crop){
if ($w < $width or $h < $height) return array(false,"Picture is too small! Min size $width px X $height px");
$ratio = max($width/$w, $height/$h);
$h = $height / $ratio;
$x = ($w - $width / $ratio) / 2;
$w = $width / $ratio;
} else {
if($w < $width and $h < $height) return array(false,"Picture is too small! Min size $width px X $height px");
$ratio = min($width/$w, $height/$h);
$width = $w * $ratio;
$height = $h * $ratio;
$x = 0;
}
$new = imagecreatetruecolor($width, $height);
// preserve transparency
if($type == "gif" or $type == "png"){
imagecolortransparent($new, imagecolorallocatealpha($new, 0, 0, 0, 127));
imagealphablending($new, false);
imagesavealpha($new, true);
}
imagecopyresampled($new, $img, 0, 0, ($w - $width)/2, ($h - $height)/2, $width, $height, $w - (($w - $width)/2), $h - (($h - $height)/2) );
switch($type){
case 'bmp': imagewbmp($new, $dst); break;
case 'gif': imagegif($new, $dst); break;
case 'jpg': imagejpeg($new, $dst); break;
case 'png': imagepng($new, $dst); break;
}
return array(true,$dst);