|DDS Image Format|
The DirectDraw Surface container file format (uses the filename extension DDS), is a Microsoft format for storing data compressed with the proprietary S3 Texture Compression algorithm (Like JPEG's), which can be decompressed in hardware by GPUs. This makes the format useful for storing graphical textures and cubic environment maps as a data file, both compressed and uncompressed. DDS files are usually contained in special BIN file's. Keep in mind this file type uses Lossy Compression which means you'll lose quality every time you save it. Persona 5 saves them in multiple images to hide the Lossy Compression.
Paint.NET fully supports DDS editing and saving.
DDS2Tool can extract and combine DDS file's to save time. It was made by Ryan ShrineFox
Windows Texture Viewer
Nvidia's texture viewer for Windows users accessible | here.
RenderDoc can also be used as an image viewer for DDS when set as the primary application for DDS files.