I wanted a one-line answer to a small question: when I shrink a PNG that has a cut-out edge, which of the browser and Node resize calls quietly mix the colour stored under the transparent pixels into the edge? I answered it with a table built from one image. I am a tool person, not an imaging person, so everything below comes from what the pixels did, not from reading library source.

The test image is a portrait from Wikimedia Commons (CC BY-SA 4.0, by Dmitry Makeev), scaled to 1330×2000 and cut out with ImgIng (图映), a browser tool at https://imging.ai/ that I used on a desktop.…