A solution is proposed that performs global histogramming of pre-regionally-enhanced pixel values accounting for inter-regional illumination contributions to verify that over-saturation of an image is prevented. According to an embodiment, pixel values that have been regionally enhanced—that is, with applied gains calculated for the respective regions—are further added to illumination values corresponding to the pixel values, with the resultant summed pixel values being histogrammed again to determine the amount of over-saturated pixels. An over-abundance of over-saturated pixels results in a calculation of a global modifier applied to each pixel to reduce the number of over-saturated pixels below an acceptable threshold.