I just need to edit this image.

Etch is a fast, simple, native image editor for Linux, closer to Paint than to Photoshop. Open a PNG, JPEG, or BMP, draw with the pencil, brush, fill, lines, rectangles, ellipses, and text, select and move pixels, copy and paste with other apps, crop, resize, rotate, and flip, then save. Every step undoes.

Download for Linux

FamiliarTools on the left, colours at the bottom, Paint's keys: P, B, E, F, T, S, X.
ImmediateA stroke on an 8K image draws in about a millisecond a frame.
Sharp up closePixels stay square from 100% to 3200%.

Install

For your user, no sudo: the app and its menu entry. Start it from your app menu or with etch. Run the command again to update. It makes Etch the default app for PNG, JPEG, and BMP images, so double-clicking one opens it in Etch; other file types keep their apps, and removing Etch drops its defaults.

curl -fsSL https://this-site/install.sh | sh

It needs GTK 4, which GNOME desktops have; otherwise the installer says how to get it. Or download the tarball above and check it against the published sha256. To remove it:

curl -fsSL https://this-site/install.sh | sh -s -- --uninstall