1. A method for estimating a scene illuminant in an image sensor device, comprising: generating a plurality of illuminant characteristic curves; capturing pixel data corresponding to a scene under a scene illuminant; generating a pixel characteristic curve for a subset of the pixel data in a color space subset; comparing the pixel characteristic curve to the plurality of illuminant characteristic curves to estimate the scene illuminant; generating a plurality of image sensor device responses to a training set under a plurality of candidate illuminants, the training set comprising a plurality of natural surfaces; normalizing the plurality of image sensor device responses and projecting the plurality of normalized image sensor device responses into the color space subset; and finding a chromaticity trend in the plurality of normalized image sensor device responses in the color space subset to generate the plurality of illuminant characteristic curves, wherein generating the plurality of illuminant characteristic curves comprises measuring spectral sensitivities of the image sensor device for red, blue, and green color channels, and wherein finding the chromaticity trend in the plurality of normalized image sensor device responses comprises applying a statistical trend analysis to the plurality of normalized image sensor device responses to determine a plurality of trend coefficients, the plurality of trend coefficients representing the plurality of illuminant characteristic curves.