Gaussian blur alternative for bloom effects

Johannes Solidakis · 2019-05-06T16:50:49

Perusing various articles on different blur algorithms for a bloom step, they all seem to regard a gaussian blur as the convolution of choice. However, after putting it to the test with a large array of conditions, I came to the conclusion that a gaussian blur isn't as visually appealing as one would expect, not even taking artifacts incurred by cheap approximations into account. No matter how large a kernel and standard deviation I use, the bloom cuts off way too abruptly in a circle around bright centers. By artificially deviating from a standard gaussian curve and adding more weight to the center of a kernel without reducing the tail too much, I achieve results that I find to be more pleasing and in line with what I expect bloom to look like. Now, arbitrarily tuning the weights with no physical or mathematical basis isn't exactly ideal, so I am wondering if there is an appropriate alternative to the good old bell curve for this purpose.