Pictor (v 1.27.0) is an interesting image editor that while basic looking has some not often seen features.
Of these more unique features are 36 predefined collage shapes that arrange 2 to 25 images in different configurations. Plus a whole set of shapes (geometric, stars, arrows etc.) that can be added to images. Perhaps more unusual is the crop and erase features where an image can be cropped using a shape instead of a rectangular crop. Free hand cropping is also a less common option. In the screenshot below Crop —> Crop by shape is chosen and drawn on the image. After drawing the shape clicking enter crops the image leaving only the parts of the image within the triangular shape. The Erase option does the opposite by erasing a (triangular) shape and leaving the rest of the image intact. The crop has a few more options as well with one being crop by text whereby a typed text remains with the the rest of the image cropped.
The Add menu adds text and other images to the existing image. This feature includes a ‘Text Circle’ option where the text entered is drawn in a within a resizable circle, a less configurable feature of something seen in the likes of Photoshop. The Replace option is like overlaying the open image with another.
Pictor also does batch (resize, rotate, add image, etc) processing plus the expected gamma, brightness, grayscale, negative, emboss and others under the Color menu. It also features various pens for drawing on images with various thicknesses.
An important limitation seems to be that the program supports only one Undo level and further changes are therefore destructive.
Pictor is portable and less than 3MB unzipped. It supports most standard set of image formats including the likes of EJPG, WebP and PGM.