lux is an image viewer for 'normal' images and the most common types of panoramic images, typically showing a 'rectilinear' view to the image data, which looks as if this view had been taken with an 'ordinary' lens. The view can be zoomed, panned, scrolled, rotated and modified in several ways. lux displays images, it does not modify them. But it can produce high-quality images from the view it shows. lux can also produce synoptic views of several images and do stitching, HDR blending, exposure fusions, focus stacks and deghosting, usually from 'PTO' files, processing a subset of the panotools standard used by panorama stitching software like hugin.
lux uses vigraimpex for image import, so it can open a variety of image file formats, including JPG, TIFF, PNG, and EXR. lux can also open PTO files - this is a format desribing synoptic views for panoramas, used by software like hugin. When displaying PTO files, lux will show a synoptic view of the set of images in the PTO file which can be manipulated like a single image. lux also has it's own file format, the 'lux ini file', or 'lux file' for short, using the .lux extension. It's a simple list of key-value pairs, like in 'regular' ini files, and it's used to bundle sets of parameters.
You'll get the hang of using lux quickly - if you've used other image viewers before, the basic UI should come naturally, but beyond that there is a lot more to discover, and viewing panoramic images goes beyond merely looking at a rectangular view of some larger rectangle - with a 'full spherical' you can 'look' all around you, and lux is a tool to let you do just that. The user interface is inspired by 360cities' QTVR mode and may feel strange to new users, but it's well-suited for panorama display.
