Phototonic is an image viewer and organizer for Linux written in C++ and Qt5.

Features: - Light weight with a smooth and clear user interface - Does not depend on any desktop environment - Supports several customized thumbnail layouts - Load thumbnails and browse images recursively on a folder tree - Dynamic thumbnails loading, enables fast browsing of very large folders - Filter thumbnails by name - Image navigation and file management - Slide show - Transformation: rotation, flipping, cropping, image mirroring and scaling - Adjust image brightness, saturation, hue and contrast - Keep transformations, zoom and colors while browsing multiple images - Extensive automatic and manual zoom options - Supported image formats: BMP, GIF, ICO, JPEG, MNG, PBM, PGM, PNG, PPM, TGA, XBM, XPM and SVG, SVGZ, TIFF with plugins - Supports GIF animations - Keyboard shortcuts and mouse behavior customization - Load image files or folders from command line - Open images with external applications