Comment by joshvm

> I am vaguely aware of stuff like Gaussian blur on Photoshop. But I never really knew what it does.

Blurring is a convolution or filter operation. You take a small patch of image (5x5 pixels) and you convolve it with another fixed matrix, called a kernel. Convolution says multiply element-wise and sum. You replace the center pixel with the result.

https://en.wikipedia.org/wiki/Box_blur is the simplest kernel - all ones, and divide by the kernel size. Every pixel becomes the average of itself and its neighbors, which looks blurry. Gaussian blur is calculated in an identical way, but the matrix elements follow the "height" of a 2D Gaussian with some amplitude. It results in a bit more smoothing as farther pixels have less influence. Bigger the kernel, more blurrier the result.There are a lot of these basic operations:

https://en.wikipedia.org/wiki/Kernel_(image_processing)

If you see "Gaussian", it implies the distribution is used somewhere in the process, but splatting and image kernels are very different operations.

For what it's worth I don't think the Wikipedia article on Gaussian Blur is particularly accessible.