I don't know much about Embromix but I know about Advanced Embroidery Designs. They have created lots of photo stitch designs, maybe they can help you. The link os below.
Yes that is the site I had ordered the Westie dog pattern from and it stitched out wonderful
Just looking at the site and having downloaded free designs I would trust it. Hopefully someone else will come along and comment. I believe I bought a dog pattern once at the beginning when I did not mark where it came from.