Possible to resize an image (client side) on an html form before upload?

I have a standard html input form that includes a field for uploading a file (image).

I unfortunatly cannot edit the backend php that processes the file, but I need to resize the images to a certain size.

I was thinking I could pull off this trick by having the images resized by jquery or alternative client side methods, on the form, before the actual submission to the PHP form.

Is this possible? Anyone know of a good method?

Thanks!!!