Imagine (Version: 1.0.8 as of this post) is a full featured image viewer and thumbnail browser. It features rotate, flip, negative and other common effects and filters. Support for plugins and command line parameters as well. It also supports animation creation, a feature less common in image viewers.
Via Tools —> Animation Factory one can create animations. It supports setting delays between frames, setting transparency, resizing the animation, fliping frames horizontally or vertically and even manipulating the colors of the images. It is also possible to extract frames from an existing animation.
Another feature often missing or incomplete in many image viewers is to not only be able to open archive files but to be able to get proper thumbnail views of the images inside. Imagine supports this in ZIP, RAR, 7Z, ALZ, HV3, CBZ, CBR and CB7 formats and in my tests supports them well.
Imagine supports EXIF data and their retention when re-saving images. Shell extension support is here too. Via Options —> Shell Extension the preview of an image will be available when right clicking it.
Imagine can create multiple page images, do batch conversions, show slideshows and take screenshots. The latter was a bit different as it somehow proceeded to take many screenshots, not just one, when the trigger method was set to ‘automatically after X seconds’, it thus behaved as ‘automatically after every X seconds’.
Unicode and 64-bit versions are also available, it should run on all Windows versions and doesn’t write to the registry.
Imagine is highly recommended.