Resize png seems doesn't work

[luX0r-reload]

Hi,
I'm using your plugin with ajax and multiupload with images redim.
Images are uploaded correctly but png images are not redim. With jpg all works fine.
This is my plugin call:

jQuery("#foto_upload").fileinput({theme: "fa", language:"it", allowedFileExtensions: ["jpg", "png", "gif"], uploadUrl: "<?php echo $someurl ?>", maxImageHeight: 768, maxFileCount: 5, resizeImage: true });

My environment:

• Mozilla Firefox 55.0.3
• Linux
• jQuery v1.12.4
• bootstrap fileinput v4.4.3

Attachment is one of the png I can try to upload already redim.

Thanks in advance.

EDIT: I'm try to upload attached png in demo plugin page too... same results. png is not resized:
http://plugins.krajee.com/file-image-management-demo

Luca