We’ve had a lot of digital image processing tools for a long time: Photoshop, Lightroom, GIMP, PhotoScape, and many more. However, in the past few years, one became popular among non-expert users due to its easiness of use and social features: Instagram. Have you ever wondered how Instagram filters work? It is actually pretty simple matrix operations! So simple we can build our own without any external library, just pure and simple HTML + JS. Let’s build one now.