1. An automatic white balancing system, the system comprising: a cast detector configured to receive and classify an input image based at least in part on a selection of constituent pixels of the input image, wherein the cast detector is further configured to select the constituent pixels based on a computed reliability of each of the constituent pixels to convey at least one characteristic of a capture illuminant, the cast detector including: a pixel processing unit configured to select the constituent pixels from the input image, wherein the pixel processing unit is configured to: select the constituent pixels having a green value (G) lying in a predetermined range; define a weighted function of the green value, the weighted function being so defined to assign a higher weight to a middle band green value; for each selected constituent pixel, compute a range of red and blue values based on the green value of the constituent pixel; for each non-saturated constituent pixel, compute a first metric and a second metric based on a comparison of the red and blue values of the non-saturated constituent pixel; and compute a first pixel count and a second pixel count corresponding to the first and second metrics respectively; and an image-classifying unit configured to classify the input image based on red, green, and blue values of the constituent pixels selected by the pixel processing unit; and a cast balancer configured to perform white balancing of the input image based on the classification of the input image by the cast detector, wherein the cast balancer is further configured to identify the capture illuminant based on at least one characteristic represented by each of the selected constituent pixels.