Systems and methods for separating a digital image using a specified colour palette into a sequence of separation plates used in a multi-stage printing process to produce an acceptable facsimile of the digital image

1. A method of separating a digital image using a specified colour palette into a sequence of separation plates for subsequent use in multi-stage printing processes to produce an acceptable facsimile of user-selected artwork, wherein the digital image has a plurality of pixels, each pixel having a pixel colour value within a particularly-defined colour space, the specified colour palette is an ordered list of a plurality of printing inks, each of the plurality of printing inks having a colour value within the particularly-defined colour space, the method comprising:

receiving, on a processor, the digital image and the specified colour palette;

setting, on the processor, a desired number of ink quantization levels, Q;

determining, on the processor, a plurality of ink levels, the plurality of ink levels including zero and one hundred percent and additional intermediate levels there between when the desired number of ink quantization levels is greater than zero, the additional intermediate levels being evenly spaced between zero and one hundred percent based on the value of Q;

combining, on the processor, all of the plurality of ink levels by Cartesian product for each of the plurality of printing inks to form a list of all possible ink combinations based on the desired number of ink quantization levels;

calculating the colour values within the colour space for one or more composite colours by linear combination of the colour values of each of the possible ink combinations, weighted by the ink levels, as the colour value for each potential colour separation combination;

for each pixel colour value in the digital image finding, on the processor, the potential colour separation combination colour value that is the closest distance to the pixel colour value,

adding, on the processor, each of the printing ink-ink level pairs that resulted in the closest potential colour separation combination colour value to a final combination colour palette, and including each of the plurality of pixels associated with the pixel colour value on a separation plate logically associated with each of the printing inks that resulted in the closest potential colour separation combination colour value;

ordering the printing ink, ink level pairs within the final combination colour palette; and

returning the final combination colour palette and separation plates.

2. The method according to claim 1 wherein the desired number of ink quantization levels is an integer.

3. The method according to claim 2 wherein each of the additional intermediate ink levels are integers.

4. The method according to claim 3 wherein the additional intermediate ink levels are rounded to the nearest integer value.

5. The method according to claim 1 wherein only certain of the plurality of printing inks are available for use, the method further comprising:

finding colour values within the particularly-defined colour space for each of the available printing inks; and

deleting the colour value calculated for each potential colour separation combination if it is not equal to a colour value of one of the available printing inks.

6. A system for separating a digital image using a specified colour palette into a sequence of separation plates for subsequent use in multi-stage printing processes to produce an acceptable facsimile of user-selected artwork, the system comprising:

a processor that has received the digital image and the specified colour palette, wherein the digital image has a plurality of pixels, each pixel having a pixel colour value within a particularly-defined colour space and the specified colour palette is an ordered list of a plurality of printing inks, each of the plurality of printing inks having a colour value within the particularly-defined colour space, the processor being configured to process the digital image in accordance with program logic;

a memory containing the program logic that configures the processor to set a desired number of ink quantization levels, Q,

determine a plurality of ink levels, the plurality of ink levels including zero and one hundred percent and additional intermediate levels there between when the desired number of ink quantization levels is greater than zero, the additional intermediate levels being evenly spaced between zero and one hundred percent based on the value of Q,

combine all of the plurality of ink levels by Cartesian product for each of the plurality of printing inks to form a list of all possible ink combinations based on the desired number of ink quantization levels,

calculate the colour values within the colour space for one or more composite colours by linear combination of the colour values of each of the possible ink combinations, weighted by the ink levels, as the colour value for each potential colour separation combination,

for each pixel colour value in the digital image

find the potential colour separation combination colour value that is the closest distance to the pixel colour value,

add each of the printing ink-ink level pairs that resulted in the closest potential colour separation combination colour value to a final combination colour palette, and

include each of the plurality of pixels associated with the pixel colour value on a separation plate logically associated with each of the printing inks that resulted in the closest potential colour separation combination colour value,

order the printing ink, ink level pairs within the final combination colour palette; and

return the final combination colour palette and separation plates.

7. The system according to claim 6 wherein the desired number of ink quantization levels is an integer.

8. The system according to claim 7 wherein each of the additional intermediate ink levels are integers.

9. The system according to claim 8 wherein the additional intermediate ink levels are rounded to the nearest integer value.

10. The system according to claim 6 wherein only certain of the plurality of printing inks are available for use, the program logic further configuring the processor to:

find colour values within the particularly-defined colour space for each of the available printing inks; and

delete the colour value calculated for each potential colour separation combination if it is not equal to a colour value of one of the available printing inks.