Abstract: A visual sensor has a first portion and a second portion. The sensor is able to detect the state of one or more imaging parameters such as exposure setting, pulse width modulation, focus, balance, spot ellipticity, sidelobe size, shape, and intensity, media gamma, edge sharpness, dot gain, uniformity, ink receptivity, physical changes in the media, pattern dependent effects such as dot gain or tone resolution compared to the type of halftone used, and sensitivity to calibrated position or exposure errors. The first image portion has a first imaging characteristic, and the second image portion has a second imaging characteristic. Imaging characteristics are characteristics of an image, including, but not limited to apparent density level, tint, color, reflectivity, absorption, granularity or microstructure, size, shape, distribution, degree of randomness, structure, edge sharpness, and depth or dimension.