Convert the transparent background of a PNG image to opaque while image to transparent
usage: png-background-to-img.py [-h] [-i INPUT_FILENAME]
[-a BACKGROUND_OPACITY] [-o OUTPUT_FILENAME]
optional arguments:
-h, --help show this help message and exit
-i INPUT_FILENAME, --input-filename INPUT_FILENAME
The Full Input Filename (Must Be *png)
-a BACKGROUND_OPACITY, --background-opacity BACKGROUND_OPACITY
The alpha value a of the background pixels where 0 ≤ a
≤ 255 (Default: 255)
-o OUTPUT_FILENAME, --output-filename OUTPUT_FILENAME
The Full Output Filename (Default: shadow-art.png)