1. A method of watermarking a text message onto an input image, comprising the following steps: (a) converting the text message into a binary-coded data bit sequence of logic 0 data bits and logic 1 data bits; (b) assigning a first bit-pattern symbol to logic 0 data bits within said binary-coded data bit sequence, said first bit-pattern symbol being a first predefined geometric arrangement of individual image dots; (c) assigning a second bit-pattern symbol to logic 1 data bits within said binary-coded data bit sequence, said second bit-pattern symbol being a second predefined geometric arrangement of individual image dots distinct from said first predefined geometric arrangement of individual image dots; (d) defining a non-data, marker bit, and assigning a third bit-pattern symbol to said marker bit, said third bit-pattern symbol being a third predefined geometric arrangement of individual image dots distinct from said first and second predefined geometric arrangements of individual image dots; (e) arranging said binary-coded data bit sequence into a predefined geometric configuration having a perimeter outlined by repeated instances of said marker bit; (f) assigning contiguous copies of said geometric configuration to span said input image; and (g) writing said first, second, and third bit-pattern symbols over said input image in accordance the occurrence of their corresponding logic 0 data bit, logic 1 data bit, and marker bit in the assignment of step (f) and an image mask.