- 1 Formats
- 1.1 Colour
- 1.2 SVG
- 1.3 TIFF
- 1.4 JPG
- 1.5 GIF
- 1.6 PNG
- 1.7 APNG
- 1.8 WebP
- 1.9 BPG
- 1.10 HVIF
- 1.11 HEIF
- 1.12 FLIF
- 1.13 ETC
- 1.14 PSD
- 1.15 PostScript
- 1.16 PDF
- 1.17 XPM
- 1.18 Other
- 1.19 ASCII
- 1.20 Web 1.0 stylee
- 2 Resources
- Photography Stack Exchange: terminology - What does "frequency" mean in an image?
- How media queries allow you to optimize SVG icons for several sizes - Opera, Oct 12, 2009
- About those vector icons - November 4th, 2011
- SVG, Use it Already - Apr 3rd, 2012
- How to work with Scalable Vector Graphics (SVG) in HTML 5
- Creating SVG vector graphics for maximum browser compatibility - Oct 19, 2012
- SVG and Browser Support (Part 2) - using object to display png fallback for ie8
- Ways to embed a Clickable SVG-Logo into Your Website - Sep 10 2012
- https://github.com/RazrFalcon/svgcleaner - svgcleaner could help you to clean up your SVG files from the unnecessary data.
- https://github.com/scour-project/scour - an SVG optimizer/cleaner that reduces the size of scalable vector graphics by optimizing structure and removing unnecessary data written in Python.It can be used to create streamlined vector graphics suitable for web deployment, publishing/sharing or further processing.
- canvas-svg - a set of related components that make canvas and SVG play together more. Notably, it allows you to save a canvas 2D context as SVG, and to have an SVG mirror of a canvas context.
var c = document.getElementById('canvas'); var ctx = c.getContext('2d'); ctx.drawSvg(SVG_XML_OR_PATH_TO_SVG, dx, dy, dw, dh);
- MagicMarkup - Easily create interactive mockups in Inkscape, without adding inline JS!
- Vector Magic - Automatically convert bitmap images like JPEGs, GIFs and PNGs to the crisp, clean, scalable vector art of EPS, SVG, and PDF with the world's best auto-tracing software.
- 1x1px - Ever needed a 1x1 transparent PNG pixel?
Like Sass for SVG.
- Open Clip Art Library 2.0 (at 417M)
- Vecto2000 is a collection of high quality free Vector Art, Vector Icons, Vector Patterns and Photoshop Brushes
- JPEGclub.org develops new JPEG features and maintains the Independent JPEG Group's (IJG) software.
- jpegoptim is a utility for optimizing JPEG files. It provides lossless optimization (based on optimizing the Huffman tables) and "lossy" optimization based on setting a maximum quality factor.
- Google advises; run with the --strip-all option
- Optimizing images for web with Google Page Speed and jpegoptim - 27 June, 2009
"when your JPEG image is under 10K, it’s better to be saved as baseline JPEG (estimated 75% chance it will be smaller) for files over 10K the progressive JPEG will give you a better compression (in 94% of the cases)"
- pngquant is a command-line utility and a library for converting 24/32-bit PNG images to paletted (8-bit) PNGs. The conversion reduces file sizes significantly (often as much as 70%) and preserves full alpha transparency. 
- https://blogs.dropbox.com/tech/2016/07/lepton-image-compression-saving-22-losslessly-from-images-at-15mbs/ 
- https://github.com/ImageOptim/gifski - GIF encoder based on libimagequant (pngquant, gifquant?). Squeezes maximum possible quality from the awful GIF format.
- http://mathgifs.blogspot.co.uk/ 
- http://i-am-fat.org/PNGRotateTrick/ - better compression of vertical gradients
- http://alphapun.ch/ - make transparent
- https://en.wikipedia.org/wiki/Ericsson_Texture_Compression - a lossy texture compression technique developed in collaboration with Ericsson Research in early 2005. It was originally developed under the name iPACKMAN and based on an earlier compression scheme called PACKMAN.
- https://github.com/google/etc2comp - converts textures (e.g. bitmaps) into the ETC2 format. The tool is built with a focus on encoding performance to reduce the amount of time required to compile asset heavy applications as well as reduce overall application size.
- https://en.wikipedia.org/wiki/PostScript - a page description language in the electronic publishing and desktop publishing business. It is a dynamically typed, concatenative programming language and was created at Adobe Systems by John Warnock, Charles Geschke, Doug Brotz, Ed Taft and Bill Paxton from 1982 to 1984.
- PostScript as a Programming Language - PostScript has all the programming functionality you would expect from an HP-caclulator, plus some interesting features hard to find in other languages. There are variables, loops, subroutines (of a sort), and an advanced idea for the scope of variables.
- https://en.wikipedia.org/wiki/Remote_Imaging_Protocol - associated Remote Imaging Protocol Scripting Language, RIPscrip, is a scripting language that provides a system for sending vector graphics over low-bandwidth links, notably modems. It was originally created by Jeff Reeder, Jim Bergman, and Mark Hayton of TeleGrafix Communications in Huntington Beach, California to enhance bulletin board systems and other applications.
Web 1.0 stylee
- Fontello - icon fonts generator
- Gnome Icons
- Tango Desktop Project exists to help create a consistent graphical user interface experience for free and Open Source software.
- Open Icon Library - Free for anyone to use on you computer, website or any other project.
- Famfamfam icons
- Chalkwork is a visually unified set of carefully designed icons.
- Modern UI Icons - Handcrafted pixel perfect vector icons.
- Glyphicons is a library of precisely prepared monochromatic icons and symbols, created with an emphasis on simplicity and easy orientation.
- The Noun Project
- GoSquared Resources
- flat.icns 
- Maki is a clean point of interest icon set made for web cartography.
- SJJB SVG Map Icons - an attempt to create a simple consistent set of vector icons suitable for cartographic use.
- Game-icons.net - free SVG and PNG icons for your games
- Climacons - climatically categorised pictographs for web and user interface designers.
- LivIcons - Truly animated icon pack with power of scalable vector graphic for clean and perfect look at any devices.
- Iconfinder - Browse free icon sets
- Icons Guide helps you to find the best stock icons shop you are looking for.
- Icon Pot lists free icons and stock web icons which are all great to use for your web design projects
- Find Icons - icon search engine
- Icon Fever - helping you find the best icons
- Icon Archive - icon search
- Icon Deposit - post your icons, designs, code, and screenshots to promote your work
- iconmelon - svg icons library for web
- Evil Icons - Lightweight SVG icons for your web project
- https://github.com/sixsixfive/Monotone - A Monotone icon theme that contains over 1300 scalable icons to cover more than 5500 icons from the last linux decade. Its mainly made for dark desktops or HTPC's however it can also be used as a pure action/toolbar icon theme, fallback icon theme or even on bright desktops after a color change.
Open and free
- OpenClipart - High Quality, Easy to Use, Free Support
- Pexels - Free stock photos
- Devices - Images and Sketch files of popular devices, by Facebook Design
- https://github.com/chrieke/awesome-satellite-imagery-datasets - List of aerial and satellite imagery datasets with annotations for computer vision and deep learning. Newest datasets at the top of each category (Instance segmentation, object detection, semantic segmentation, scene classification, other).
- IconDrop - A desktop app for searching and using free SVG icons
- https://github.com/EmbarkStudios/texture-synthesis - art Example-based texture synthesis written in Rust crab