inkmap v0.1.1

Fixes from Kestrel's review (#2613):

• --out on the input's own folder no longer overwrites the original: inkmap refuses (#664).
• Two inputs with the same name in one run no longer overwrite each other: the second fails (#665).
• A sketch with a transparent margin keeps its drawing; only a picture with no paper level is treated as a cutout (#666).

inkmap 0.1.0

First release.

Makes the ink of every pen sketch the same colour: each pixel becomes a coverage from paper to the picture's own darkest ink, then is painted as that much of your ink on your paper, so line weight is kept and hue and paper tint are replaced. Transparent cutouts keep their alpha.

Install: cargo install --git https://github.com/mackenziebowes/inkmap

Known: WebP is written lossless, so files grow (a 187 KB WebP came back at about 1.5 MB). Re-encode for the web with cwebp or magick.