Printer calibration mechanism

1. A system comprising:

at least one physical memory device to store calibration logic; and

one or more processors coupled with the at least one physical memory device to execute the calibration logic to:

receive a reference halftone design;

receive reference ink drop size data;

receive a reference printer transfer function corresponding to the reference halftone design, a reference printer response target and a reference print substrate;

receive first print measurement data corresponding to the reference halftone design, the reference printer transfer function and a first print substrate;

receive first printer response target;

generate a first intermediate print substrate transfer function based on the first print measurement data and the first printer response target;

generate a first printer transfer function based on the first intermediate print substrate transfer function, the reference halftone design, the reference ink drop size data and the reference printer transfer function; and

generate a first print substrate transfer function as an approximation of a function with input values determined as the first printer transfer function evaluated at digital count values and output values determined as a composition of the first intermediate print substrate transfer function and the reference printer transfer function evaluated at the digital count values;

wherein a transfer function comprises a mapping of an input digital count to an output digital count.

2. The system of claim 1 , wherein generating the first printer transfer function further comprises equating reference ink usage volumes corresponding to the reference printer transfer function with first ink usage volumes corresponding to the first print measurement data.

3. The system of claim 2 , wherein equating the reference ink usage volumes with the first ink usage volumes comprises determining first ink drop sizes corresponding to the first print measurement data.

4. The system of claim 3 , wherein determining first ink drop sizes corresponding to the first print measurement data comprises determining reference ink drop usage fraction data corresponding to the reference printer transfer function; wherein ink drop usage fraction data represents a number of drops for a specific instructed drop size at a given DC level divided by a total number of drops possible for a halftone design.

5. The system of claim 1 , wherein the calibration logic further to receive an updated first print measurement data corresponding to the reference halftone design, the reference printer transfer function and the first print substrate and generate an updated intermediate printer transfer function, an updated first printer transfer function, and an updated first print substrate transfer function.

6. The system of claim 5 , wherein generating the updated first printer transfer function and generating the updated first print substrate transfer function comprises the first print substrate transfer function and the reference printer transfer function as baseline references.

7. The system of claim 1 , further comprising initiation of generating a second printer transfer function and a second substrate transfer function in response to identifying a second substrate different than the first substrate.

8. The system of claim 7 , wherein generating the second printer transfer function is based on received second print measurement data; wherein received second measurement data corresponds to the reference halftone design, the reference printer transfer function and a second print substrate.

9. The system of claim 1 , further comprising generating a composite transfer function based on a mathematical composition of the first print substrate transfer function and the first printer transfer function.

10. The system of claim 1 , further comprising one or more print engines.

11. At least one non-transitory computer readable medium having instructions stored thereon, which when executed by one or more processors, cause the processors to:

receive a reference halftone design;

receive reference ink drop size data;

receive a reference printer transfer function corresponding to the reference halftone design, a reference printer response target and a reference print substrate;

receive first print measurement data corresponding to the reference halftone design, the reference printer transfer function and a first print substrate;

receive first printer response target;

generate a first intermediate print substrate transfer function based on the first print measurement data and the first printer response target;

generate a first printer transfer function based on the first intermediate print substrate transfer function, the reference halftone design, the reference ink drop size data and the reference printer transfer function; and

generate a first print substrate transfer function as an approximation of a function with input values determined as the first printer transfer function evaluated at digital count values and output values determined as a composition of the first intermediate print substrate transfer function and the reference printer transfer function evaluated at the digital count values;

wherein a transfer function comprises a mapping of an input digital count to an output digital count.

12. The computer readable medium of claim 11 , wherein generating the first printer transfer function further comprises equating reference ink usage volumes corresponding to the reference printer transfer function with first ink usage volumes corresponding to the first print measurement data.

13. The computer readable medium of claim 12 , wherein equating reference the ink usage volumes with the first ink usage volumes comprises determining first ink drop sizes corresponding to the first print measurement data.

14. The computer readable medium of claim 13 , wherein determining first ink drop sizes corresponding to the first print measurement data comprises determining reference ink drop usage fraction data corresponding to the reference printer transfer function; wherein ink drop usage fraction data represents a number of drops for a specific instructed drop size at a given DC level divided by a total number of drops possible for a halftone design.

15. The computer readable medium of claim 11 , having instructions stored thereon, which when executed by one or more processors, further cause the processors to:

receive an updated first print measurement data corresponding to the reference halftone design, the reference printer transfer function and the first print substrate; and

generate an updated intermediate printer transfer function, an updated first printer transfer function, and an updated first print substrate transfer function.

16. A method comprising:

receiving a reference halftone design;

receiving reference ink drop size data;

receiving a reference printer transfer function corresponding to the reference halftone design, a reference printer response target and a reference print substrate;

receiving first print measurement data corresponding to the reference halftone design, the reference printer transfer function and a first print substrate;

receiving first printer response target;

generating a first intermediate print substrate transfer function based on the first print measurement data and the first printer response target;

generating a first printer transfer function based on the first intermediate print substrate transfer function, the reference halftone design, the reference ink drop size data and the reference printer transfer function; and

generating a first print substrate transfer function as an approximation of a function with input values determined as the first printer transfer function evaluated at digital count values and output values determined as a composition of the first intermediate print substrate transfer function and the reference printer transfer function evaluated at the digital count values;

wherein a transfer function comprises a mapping of an input digital count to an output digital count.

17. The method of claim 16 , wherein generating the first printer transfer function further comprises equating reference ink usage volumes corresponding to the reference printer transfer function with first ink usage volumes corresponding to the first print measurement data.

18. The method of claim 17 , wherein equating the reference ink usage volumes with the first ink usage volumes comprises determining first ink drop sizes corresponding to the first print measurement data.

19. The method of claim 18 , wherein determining the first ink drop sizes corresponding to the first print measurement data comprises determining reference ink drop usage fraction data corresponding to the reference printer transfer function; wherein ink drop usage fraction data represents a number of drops for a specific instructed drop size at a given DC level divided by a total number of drops possible for a halftone design.

20. The method of claim 16 , further comprising:

receiving an updated first print measurement data corresponding to the reference halftone design, the reference printer transfer function and the first print substrate; and

generating an updated intermediate printer transfer function, an updated first printer transfer function, and an updated first print substrate transfer function.