1. An image sensor device comprising: an uncovered imaging array having M rows and N columns of pixels; a covered global reference non-imaging array comprising at least one global reference row, as at least one dark row of non-imaging pixels; imaging array sampling logic configured to sample each of the M rows of pixels of the uncovered imaging array to obtain M sets of image pixel sample values, each of the M sets of image pixel samples having N image pixel sample values; global reference non-imaging array sampling logic configured to sample one dark row of said covered global reference row non-imaging array to obtain a set of reference pixel sample values, and wherein said one dark row is sampled simultaneously with the sampling of each respective row of the M rows of the uncovered imaging array such that M sets of the reference pixel sample values from the one dark row are obtained; averaging circuitry configured to average each of the M sets of the reference pixel sample values to obtain M average values each associated with a respective set of the image pixel sample values of the M sets; and imaging array sample selection circuitry configured to select the N image pixel sample values of a respective set of the M sets of image pixel sample values from the uncovered imaging array; difference circuitry, for each of the M sets of image pixel sample values of the uncovered imaging array, configured to receive the selected set of image pixel sample values and the average value associated with the selected set of image pixel sample values of the uncovered imaging array from the averaging circuitry, wherein the difference circuitry is further configured to subtract the average value associated with the selected set of image pixel sample values from each of the N image pixel sample values of the selected set to obtain M sets of N output image sample values.