  We present Convolutional Mean (CM) - a simple and fast convolutional neural
network for illuminant estimation. Our proposed method only requires a small
neural network model (1.1K parameters) and a 48 x 32 thumbnail input image. Our
unoptimized Python implementation takes 1 ms/image, which is arguably 3-3750x
faster than the current leading solutions with similar accuracy. Using two
public datasets, we show that our proposed light-weight method offers accuracy
comparable to the current leading methods' (which consist of thousands/millions
of parameters) across several measures.
