1. A system comprising: a main image processing engine, implemented at least in part in a graphics processing unit, wherein the main image processing engine is configured to: receive, from image capture components, an input image, provide a reduced-size version of the input image, and provide, to a display or a memory, an output image; and an image co-processing engine, implemented at least in part in an application-specific integrated circuit, wherein the image co-processing engine is configured to: receive, from the main image processing engine, the reduced-size version of the input image; and generate a two-dimensional chrominance histogram of the reduced-size version of the input image; convolve the two-dimensional chrominance histogram with a filter to create a two-dimensional heat map, wherein entries in the two-dimensional heat map represent respective estimates of how close respective tints corresponding to the respective entries are to a white point of the reduced-size version of the input image; select an entry in the two-dimensional heat map that represents a particular value that is within a threshold of a value in the heat map that represents a tint that is closest to the white point, apply the filter to the reduced-size version of the input image to determine output coefficients, wherein the filter is parameterized by the selected entry, and provide, to the main image processing engine, the output coefficients, wherein the output image is based on the output coefficients.