1. A method of arranging and storing imagery data and filter coefficients in a Cellular Neural Networks (CNN) based digital integrated circuit (IC) for extracting features out of an input image, the CNN based digital IC containing NE number of CNN processing engines connected in a loop via a clock-skew circuit, NE is a positive integer, the method comprising: (a) determining number of imagery data groups required for storing NIM sets of imagery data in the CNN processing engines, each imagery data group containing NE sets of the NIM sets of imagery data, where NIM is a positive integer; (b) circularly storing the NE sets of the imagery data of said each imagery data group in the respective CNN processing engines; (c) repeating (b) for the remaining imagery data groups; (d) determining number of filter groups required for storing all filter coefficients for NF number of filters in the CNN processing engines, each filter group containing NE sets of filter coefficients and said each filter group being further divided into one or more subgroups with each subgroup containing a portion of the NE sets that correlates to a corresponding group of the imagery data groups, where NF is a positive integer; (e) storing the portion of the NE sets of filter coefficients in a corresponding one of the CNN processing engines, the portion of filter coefficients being arranged in a cyclic order for accommodating convolution operations with imagery data received from an upstream neighbor CNN processing engine; and (f) repeating (e) for the remaining subgroups; and (g) repeating (e) and (f) for the remaining filter groups.