PosterizeImager is a tool that can create images like poster or illustration from photos with a method to decrease number of colors.
Since the gradation of original image is restricted, flat coloring images like anime or comic can be got.
The degradation colors also can be converted to the different color of original image using user designed color table.
Since the app can draw edge lines on the boundary between same color areas, line drawing like manga can be created.
For the edge lines, line width, color, or shadow can be specified, and coordinate conversion - translate, rotate, or scaling also can be applied.
Moreover, copy and paste for edge lines are utilized, these can be drawn on the other images.
As optional functions, pen style, edge layout like annual rings, hatching (including maze pattern) and PDF export are equipped.
※You can see many samples on Instagram with #PosterizeImager.