First of, really cool article. I love fun hacks like this. There's a few things I don't get. The first one is why he's using the same global scalar values for

First of, really cool article. I love fun hacks like this. There's a few things I don't get. The first one is why he's using the same global scalar values for gain and offset for the entire image, instead of pixel-wise values. The pattern isn't uniform, so why is the correction? The second is why the optimization is just randomizing new values instead of using a better algorithm like gradient decent. This kind of stochastic search seems really wasteful. The third is why it needs to be an optimization problem at all, why not just look at the blob image? Each pixel is supposed to be white, but we see (R_max, G_max, B_max), where both G_max and B_max is < R_max, making the pixel red. So just remap the green and blue channel for each pixel to [0, R_max] instead. Then each pixel will have the same gray value of (R_max, R_max, R_max) when displaying white. This should be really straight forward in a shader.