1. A method of filtering using an approximated bilateral filter, the method comprising: adding a bilateral correction term to a first value of a signal at a point to produce a filtered signal value, the bilateral correction term being a product of a summation term and an approximation of a normalization factor of an exact bilateral filter, wherein the summation term comprises a summation of products of a convolution kernel coefficient, a photometric weight, and a difference between the first value of the signal and a second value of the signal at a neighboring point; and outputting the filtered signal value for one or more of storage and use by a user.