This class can resize an image keeping the size proportions.
It can open an uploaded file image in either JPEG, PNG or GIF format and resize it to given width and height.
Either the width and height can be set to auto, so it gets adjusted to keep the original image proportion based on the value set to the other dimension value.
The processed image can be saved to a new file in a given target directory with the JPEG format. The compression quality of the saved image is configurable.