Free Photo Editing Software
Flickr
Flickr is home to millions of people who share billions of photos with each other and the world. It's a photo and video sharing social network that can be used to host, share and promote images and videos. Flickr is mainly used by passionate photographers who use to platform to host their material, reach a broader audience and make new connections.
gThumb
gThumb is a free and open-source image viewer and Image organizer for the GNOME Desktop. The software can be used to view, orginize and edit BMP, GIF, ICO, JPEG, PNG, TIFF, XPM files. An importer tool is also include, it can be used for transferring photos from cameras. With the editing tool, photos can be rotated, flipped and cropped, or optimized for the right contrast ratio. gThumb is developed by the The GNOME Project and released under the GNU General Public License.
PhotoQt
PhotoQt is a free and open-source, simple yet powerful image viewer, based on Qt/QML. It mprovides provides a simple and uncluttered interface filled powerful features. PhotoQt supports GraphicsMagick, Libraw, FreeImage, DevIL, Poppler, libarchive.
MyPaint
MyPaint is a free and open-source raster grahics editor use for digital painting. The software is easy to use and works well with graphics tablets such as Wacom and the likes. MyPaint comes with a builtin brush engines that is highly configurable and allows the user to experiment by creating own brushes that can be used to create unique digital paintings.
XnResize
With XnResize you can batch resize, rotate or convert images, cross-platform. XnResize is a fast, powerful and free batch image processing tool. It allows you to adjust image height and width, apply predefined sizes, adjust wrong image orientation, choose the output filenames, all within a drag and drop interface. XnResize supports all common picture and graphic formats are supported (JPEG, TIFF, PNG, GIF, WEBP, PSD, JPEG2000, OpenEXR, camera RAW, HEIC, PDF, DNG, CR2).
FireAlpaca
FireAlpaca is the free digital painting software that is compatible with both macOS and Windows.
Phototonic
Phototonic is a fast and functional, open source image viewer and organizer. The software is written in C++/Qt and released for free under GNU General Public License v3. Phototonic takes inpiration from traditional image views and provides overview of your inventory with thumbnails and organized layouts.
Eye of Gnome
The classic Eye of GNOME is the official and default image viewer for the free and open source desktop environment GNOME. The application comes bundled with GNOME and is in later releases known as Image Viewer. However, Eye of GNOME can be used in any Linux operating system or distribution. It also share many similarities with another official image viewer for GNOME called gThumb
TinyPNG
TinyPNG is a free web-based compression tool for images. With TinyPNG you can compress images (.png, .gif and .jpg) and reduce the file size between 50-80%, without loosing any visual quality and perseving full transperancy. Perfect for people looking to host or share images online via their website. Image file size stands for about 50% of the loading time of a general website, so by decreasing the size of images will have a great impact on performance. TinyPNG also provides various plugins for platforms like Adobe Photoshop and Wordpress.