Test plan

• Toggle guides "G"
• Toggle anisotropic filtering "A"
• Toggle tile boundaries "B"
• Try to open a file that is not an image
• View exif orientation images from https://github.com/recurser/exif-orientation-examples
• View exif orientation images from https://zpl.fi/exif-orientation-in-different-formats/
• View panoramas in CrookedPanos - check for rectification
• View panoramas in 360GPanoReference

Compare features to other viewers:

• Irfanview
• Window photo viewer
• JPEGView https://sourceforge.net/projects/jpegview/ https://github.com/sylikc/jpegview
• ImageGlass https://imageglass.org/releases