A non-transitory processor-readable medium comprising instructions that when executed by a processor cause the processor to: receive a graphical element associated with an image, and embedding information; partition the graphical element into segments to accommodate a binary numerical value that represents the embedding information; pre-determine locations along the graphical element for placement of binary values from the binary numerical value; and encode the binary numerical value into the graphical element at the locations as a plurality of data carrying segments, the segments comprising a plurality of different color-space values associated with the binary values of the binary numerical value, the medium being characterised by : segments of different color-space values comprise segments of different luminance values; wherein segments of different luminance values comprise, on a scale of 0 to 255, a solid black segment having a luminance value of 0 to 0, a solid grey segment having a luminance value of 30 to 30, a black to grey gradient segment having luminance values varying from 0 to 30, and a grey to black gradient segment having luminance values varying from 30 to 0; and wherein the instructions further cause the processor to combine the encoded graphical element and the image within a print job wherein the embedded information is imperceptible to the human eye. receive a graphical element associated with an image, and embedding information; partition the graphical element into segments to accommodate a binary numerical value that represents the embedding information; pre-determine locations along the graphical element for placement of binary values from the binary numerical value; and encode the binary numerical value into the graphical element at the locations as a plurality of data carrying segments, the segments comprising a plurality of different color-space values associated with the binary values of the binary numerical value, the medium being characterised by : segments of different color-space values comprise segments of different luminance values; wherein segments of different luminance values comprise, on a scale of 0 to 255, a solid black segment having a luminance value of 0 to 0, a solid grey segment having a luminance value of 30 to 30, a black to grey gradient segment having luminance values varying from 0 to 30, and a grey to black gradient segment having luminance values varying from 30 to 0; and wherein the instructions further cause the processor to combine the encoded graphical element and the image within a print job wherein the embedded information is imperceptible to the human eye. segments of different color-space values comprise segments of different luminance values; wherein segments of different luminance values comprise, on a scale of 0 to 255, a solid black segment having a luminance value of 0 to 0, a solid grey segment having a luminance value of 30 to 30, a black to grey gradient segment having luminance values varying from 0 to 30, and a grey to black gradient segment having luminance values varying from 30 to 0; and wherein the instructions further cause the processor to combine the encoded graphical element and the image within a print job wherein the embedded information is imperceptible to the human eye. <EOS>