Printer ICC Profile Adjustment via Sparse Color Sampling
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Solution Overview
Problem
Color profiles for printers need to be adjusted when new ink is introduced, as changes in ink properties can affect colorimetry, requiring a method to update the ICC profile to maintain color accuracy without requiring extensive recalibration or knowledge of the printer's operational characteristics.
Innovation Solution
A profile transformer within the printer controller accesses the original ICC profile, prints a color sample, scans it, and calculates new forward and reverse transform values to update the lookup tables, allowing for an adjusted ICC profile that accommodates the new ink, enabling seamless printing with minimal changes in color output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a full recalibration of the ICC profile is performed when new ink is introduced, then colorimetry accuracy is maintained, but the complexity and time required for profile adjustment increases significantly
Solution Approach 1:
The patent extracts only the essential colorimetry data needed for profile adjustment by printing and scanning a simplified color sample chart rather than performing a complete recalibration. This extraction approach obtains the necessary forward and reverse transform values without requiring comprehensive measurement of all color gamut parameters, thus maintaining accuracy while reducing complexity
Solution Approach 2:
The system performs preliminary colorimetry measurements using a pre-designed color sample chart before actual printing operations. By preparing and measuring reference color samples in advance, the profile transformation values are calculated beforehand, enabling quick profile updates without disrupting production workflows
2Measurement precision
If extensive color samples are measured to update the ICC profile, then transform value accuracy is improved, but the time and resources required for profile adjustment increase
Solution Approach 1:
The patent applies partial action by measuring only a selected subset of color samples from the color gamut rather than measuring all possible colors. The color sample chart contains strategically chosen patches that provide sufficient information to calculate accurate forward and reverse transform values through interpolation, achieving adequate precision with reduced measurement time
Solution Approach 2:
Color sample charts are designed and prepared in advance with predetermined color patches that cover the essential range of color variations. This preliminary preparation allows for rapid measurement and profile calculation without requiring time-consuming on-the-fly sample generation during ink replacement
3Productivity
If the ICC profile is updated with sparse sampling of the color gamut, then profile adjustment speed is improved, but the precision of color transformation may be reduced
Solution Approach 1:
The patent changes the parameter representation by working in LAB color space rather than direct device color space. By transforming color values through the LAB intermediary space, the system achieves more accurate color transformations from sparse samples, as LAB space provides perceptual uniformity that improves interpolation accuracy between measured color patches
Solution Approach 2:
The patent introduces LAB color space as an intermediary between the printer's CMYK color space and the target color space. This intermediary transformation layer allows for more accurate profile calculations from limited samples by leveraging the perceptual properties of LAB space, effectively mediating between sparse measurements and accurate color reproduction
Data Source
AI summary
In some examples, a system receives a color sample comprising a color measurement of a proper subset of a gamut of colors printable by a printer, and computes a forward transform value and a reverse transform value based on a color profile calculated from a profiling chart comprising a set of estimated color samples calculated based on the received color sample, the forward and reverse transform values to convert between colorimetry values and color values for the printer. The system provides an adjusted color profile for the printer based on an original color profile for the printer and the computing, wherein the original color profile for the printer is associated with a substrate.