[Pekka Väänänen] you have a Panasonic TV with a broken backlight that creates an uneven pink/green color. Although not a big deal in most films, black-and-white films tend to show the most impact. So, by modeling distortion as a function, [Pekka] set to receive a conversion function that corrects the distortion before it enters the TV.
He took a few pictures with his phone, adjusted his view, and used the blur. The camera can be distorted but works as a first approximation, but that’s not what it covers here. After that, he set up the web camera and pointed it at the TV, trying to get a good profit and reduce the prices with a little Python.
Now it becomes a problem of reducing the contrast of each pixel. In the end he just wanted a random route rather than an uphill or downhill route. Now that he had the application working, it was just a matter of adding a custom shader to his video player, which includes a live shader editor. He had to hack to support the external texture, but he’s kind enough to include the shader code and patch in the article.
The result is great, and a great use for an old TV. But maybe, in some cases, it might be worth changing the backlight completely.