This is one of the best manipulation programmes for turning photos into stitches. It can only be used online and not as a download to your computer. Type Atkinson dithering into Google
On opening you c an see it asks you to choose an image which you can do from a file on your computer. Then choose the photo you want to convert.
Open the image with a Gimp, Paint or another such image manipulation software or once you have saved the image into a folder you can open it directly into DAK Graphic Studio or img2track. As you can see it uses a series of dots so you won't have long floats across the knitting or if doing dbj then it will evenly distribute the yarn across the fabric.