1. A computer-readable media having computer-program instructions executable by a processor for: receiving image information; generating a Poisson-quantization noise model from a Poisson noise model and a quantization noise model; and estimating Poisson-quantization noise in the image information using the Poisson-quantization noise model; wherein the Poisson noise model comprises: p ⁡ ( k , λ , Q ) = ∑ i = q k q k + 1 - 1 ⁢ λ i i ! ⁢ ⅇ - λ wherein k represents an intensity level, λ represents an intensity source, and Q represents quantization.