Click Open File....

At the bottom of the save dialog change the Files of Type to Image. Select your jpg, png, bmp, or gif.

Play with Conversion Options until the preview looks appealing. There are several major styles.

Some styles are iterative and take time to generate results - let them run until you are satisfied. Others may have sub-options for tweaking.

Close the Conversion Options dialog. Your image is ready to Run.

Here's a Youtube example of the same lesson.