Shrink large images on upload

Panel hooks and the resize() function make this easy. This function deletes the original image and cleans up extraneous thumbnail files to save disk space.


EXACTLY what I was looking for. :slight_smile:
Thanks for share it.

Please, if it is possible, how would you create an execption for an image name?

You could change line 12 of the code above to add another condition to the if statement.

Change this:

if ($file->type() == 'image' and ($file->width() > $maxDimension or $file->height() > $maxDimension)) {

to this:

if ($file->filename() != 'dontResizeMe.jpg' and ($file->type() == 'image' and ($file->width() > $maxDimension or $file->height() > $maxDimension))) {

Note the extra set of brackets to keep the and / or logic in line.

I’m sure there’s a more elegant way to do this, but you can use any of the $file-> methods here.

Edit: changed the or/and logic as per Lukas’ comment.

Maybe turn this into a plugin? Then it would separate logic from config.

Thank you @samnabi, this is very helpful.

You can also use

function shrinkImage($file, $maxDimension = c::get('images.maxWidth', 1000)) {

that way you can set the max. width for every environment.

1 Like

hm it seems that dontResizeMe.jpg is still resized:

 kirby()->hook('panel.file.upload', 'shrinkImage');
 kirby()->hook('panel.file.replace', 'shrinkImage');

function shrinkImage($file, $maxDimension = 1000) {

  try {      
  if ($file->filename() != 'dontResizeMe.jpg' or ($file->type() == 'image' and ($file->width() > $maxDimension or $file-        >height() > $maxDimension))) {
       $originalPath = $file->dir().'/'.$file->filename();
  $resized = $file->resize($maxDimension,$maxDimension);
  $resizedPath = $resized->dir().'/'.$resized->filename();     
  copy($resizedPath, $originalPath);
  } catch(Exception $e) {
  return response::error($e->getMessage());

I believe the or must be an and:

$file->filename() != 'dontResizeMe.jpg' and
1 Like

@lukasbestle That’s it. :slight_smile:

I also tried with @Pascalmh exemple:

   function shrinkImage($file, $maxDimension = c::get('images.maxWidth', 1000)) {

but get an error :
Parse error: syntax error, unexpected ‘(’, expecting ‘)’ in A:\UwAmp\www

The issue here is that you can’t call functions in default values. It has to be:

function shrinkImage($file, $maxDimension = null) {
  if(!$maxDimension) $maxDimension = c::get('images.maxWidth', 1000);

Perfect, thank you all, for explications and solutions.

The resize feature is great. I just wanted to add that it’s also possible to limit file sizes in the blueprint. It will not resize, just prevent too large images from ever being uploaded.

  width: 150
  height: 200

1 Like

Hi! Just came across this – it’s a great addon and easy to use for noobs like me with no Php experience.

I was wondering if there was an easy way to adjust the compression level of the JPG while the resize is taking place? Most of the images I’m looking to upload are high res photos with a great level of detail, and while the max width works great, they do lose a lot of resolution in the process.

Could you guys help me with that?


You can add a third argument to Line 18 of the gist.

$resized = $file->resize($maxDimension,$maxDimension,100);

The 100 is the image quality, anywhere from 0 to 100. Default is 80.

1 Like

thanks a lot @samnabi!

Hello and thank you for share it.
I’ve got one Problem. The images will be scaled down, but when I upload an image in portrait format, it will be rotated by 90 degrees.

Do images in portrait format get uploaded correctly if you disable resizing?

Yes they do. I also activated ImageMagic. But that did not solve the problem either.

not working for me, tried with GD and IM…

at any circumstance the original file will not be resized…

Seems to be working still for me. Are you on Kirby 2.4.1?