1. Image signal processing circuitry, comprising: an image processing pipeline configured to compute noise statistics associated with image data by: receiving a frame of the image data comprising a plurality of pixels acquired using a digital image sensor; identifying a plurality of portions of the frame of the image data, wherein each portion of the plurality of portions comprises a flat surface; calculating a plurality of gradients for each portion of the plurality of portions; determining one or more dominant gradient orientations for each portion of the plurality of portions; generating a histogram that represents a plurality of dominant gradient orientations that corresponds to the plurality of portions; and storing the histogram in a memory, wherein the histogram represents the noise statistics.