On-paper image quality metric using on-belt sensing

A system for determining for determining at least one image quality metric of a color marking device, said system comprising:

• a memory;
• a storage medium for storing data;
• and
• a processor in communication with said storage medium and said memory, said processor executing machine readable instructions for performing the method of:
• measuring image noise from target color patches with an in-line sensor, where said target color patches are on-belt single-separation device-dependent colors for a target marking device;
• calculating a given on-belt image quality metric from said image noise which has been measured;
• estimating an image quality metric on-paper for said target color marking device from said on-belt image quality metric using a correlation model for single-separation device-dependent colors for on-belt measurement with on-paper measurement;
• determining a device-independent color variation by using said estimated image quality metrics for said single-separation device-dependent colors;
• estimating a device-dependent color variation as a function of area-coverage for each colorant using said device-independent color variation;
• estimating at least one device-independent color variation for at least one device-dependent multi-separation color of interest, based upon said device-dependent color variation as a function of area-coverage using at least one of:
• a Monte Carlo simulation utilizing a printer model and said device-dependent color variation as a function of area-coverage, and a Jacobian of said printer model and a variance model and said device-dependent color variation as a function of area-coverage;
• and
• determining said image quality metric of said target marking device by using said estimated device-independent color variation for said at least one device-dependent multi-separation color of interest.

A computer-implemented method for determining at least one image quality metric of a color marking device, the method comprising:

• measuring image noise from target color patches with an in-line sensor, where said target color patches are on-belt single-separation colors for a target marking device;
• calculating a given on-belt image quality metric from said image noise which has been measured;
• estimating an image quality metric on-paper for said target color marking device with said on-belt image quality metric using a correlation model for single color separations for on-belt measurement with on-paper measurement, wherein said correlation model comprises a separation-dependent polynomial equation;
• determining a device-independent color variation by using said estimated image quality metrics for said single-separation device-dependent colors;
• estimating a device-dependent color variation as a function of area-coverage for each colorant using a device-independent color variation;
• estimating at least one device-independent color variation for at least one device-dependent multi-separation color of interest, based upon said device-dependent color variation as a function of area-coverage using at least one of:
• a Monte Carlo simulation utilizing a printer model and said device-dependent color variation as a function of area-coverage, and a Jacobian of said printer model and a variance model and said device-dependent color variation as a function of area-coverage;
• determining said image quality metric of said target marking device by using said estimated device-independent color variation for said at least one device-dependent multi-separation color of interest;
• and
• comparing said image quality metric against at least one of:
• a manufacturer's specification, and a user-defined specification;
• determining, based upon the comparison, said image quality metric of said target marking device relative to a defined tolerance;
• in response to said determination, further comprising at least one of:
• performing a diagnostic on said target marking device;
• performing a maintenance on said target marking device;
• and
• notifying an operator of said target marking device.