As designers, you most likely use many other tools or programs such as Adobe Photoshop or Adobe Flash Professional to create complex images and character animations. Edge Animate lets you reuse such creations by supporting the import of sprite sheets generated from such tools.
A sprite sheet is an image file that contains several smaller graphics in a tiled grid arrangement. By compiling several graphics into a single file, you enable Edge Animate and other applications to use the graphics while only needing to load a single file. This loading efficiency can be very helpful in situations such as building animations where performance is especially important.
Most tools let you export sprite sheets only as image files (PNG/JPEG). Adobe Flash Professional CC 2014 and later can generate Edge Animate-specific sprite sheets. You can import both types of sprite sheets - PNG/JPEG as well as the ones that are generated from Flash Professional - into Edge Animate.
You may see performance issues with Edge Animate compositions on devices if you import and use sprite sheets of size greater than 2048 X 2048 pixels.
Ensure that you have generated the sprite sheet by choosing the Edge Animate format in Adobe Flash Professional CC 2014 (or later).
For information on generating sprite sheets in Adobe Flash Professional CC, see Adobe Flash Professional CC Help.