*** UPDATE ***
There is a new .NET version here:
InView - The .NET Image Viewer
I've resumed an old project back from 2016. With a few changes now the application does work also on Windows 10.
This is an image viewer with minimalistic UI (just a shortcuts menu) and interesting features: zoom with mouse wheel and centered on the mouse pointer, zoom with a rectangle, load and display several images at the same time (multiple windows, just drag & drop the files), pan, rotation of 90°, pixel color info, copy and paste, mouse coordinates, crop the image (with zoom rect+copy and paste), flip horizontal and vertical.
Supported formats (single image): bmp, cur, emf, gif, ico, jpg, png, tif, wmf.
The application implements a simple double buffer drawing system for the image with a hidden picture box.
For the other graphics it uses the "standard" VB6 double buffer: AutoRedraw = True on the form.
In this way there are two independent drawing "layers": one for the background (image) and one for the foreground (other graphics).
Futhermore, the drawing routine is optimized to draw only the visible part of the image on the screen.
Fully portable, only the exe is required. The .manifest file is optional and is needed only if you want to inherit the display settings from the installed Windows version.