Atkinson

"Atkinson" outputs the photo processced by Atkinson dithering algorithm.
Atkinson dithering algorithm was used to display photo with black and white color on old Macintosh.
And also, the file size of photos with processed by "Atkinson" are small.

# Features
- process with Atkinson dithering algorithm
- square photo
- rounded corner (you can turn on/off)
- white border
- realtime preview