A printing system is disclosed. The printing system includes 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 perform uniformity compensation, including receiving print image measurement data corresponding to primary color markings and secondary color markings printed by pel forming elements, wherein each of the pel forming elements is associated with one of a plurality of primary colors, generating a first set of transfer functions, wherein the first set of transfer functions include a transfer function for each of the pel forming elements associated with a primary color, generating a second set of transfer functions, wherein the second set of transfer functions include transfer functions for each of the pel forming elements associated with a plurality of secondary colors and generating a set of uniformity compensated transfer functions, wherein the set of uniformity compensated transfer functions include a transfer function for each of the pel forming elements based on the first set of transfer functions and the corresponding second set of transfer functions.

A kit for usage by a nail polish application apparatus, the kit comprising one or more nail polish capsules. Each of the nail polish capsule(s) comprises a body portion defining a reservoir containing a nail polish fluid and a non-screw detachable cover having an integrated nail polish applying element. The non-screw detachable cover is mechanically coupled to an upper face of the body portion to seal an opening in the upper face.

Methods of measuring colours, methods of calibrating printers and printing systems for implementing the methods are disclosed. Calibration maps are printed on print media. The calibration maps have intertwined contiguous printed and non-printed areas. One or more colour signals are measured on contiguous printed areas. One or more noise signals are measured on non-printed areas that are adjacent to the contiguous printed areas. Clear colour signals are generated by removing the one or more measured noise signals from the one or more measured colour signals.

Methods, systems and computer readable media for color management are described. In some implementations, the method can include accessing one or more buildup curves associated with a combination of a substrate, one or more colorants and a colorant dispenser. The method can also include accessing a design file specifying a design and including one or more layer files each specifying a layer color. The method can further include generating, for each layer color, a corresponding colorization recipe based on the one or more buildup curves. The method can also include creating a production job instruction/metadata file having a link to the design instruction/metadata file and including parameters associated with the colorant dispensing job to be carried out using the design instruction/metadata file.

An image processing apparatus includes a correction factor calculating unit configured to calculate a correction factor for correcting a difference in pixel values corresponding to a difference between a spectral sensitivity and a preset reference spectral sensitivity in a predetermined wavelength range at a pixel of interest, based on image data generated by an image sensor, the image sensor having a plurality of pixels on which color filters of a plurality of colors with different spectral transmittances are respectively disposed, the color filters forming a predetermined array pattern, the correction factor calculating unit being configured to calculate the correction factor for each of the plurality of pixels on which at least a predetermined color filter of the color filters is disposed.

An image forming apparatus includes a table generating unit. The table generating unit determines whether a target-value Voronoi region and a measured-value Voronoi region are identical or not. The table generating unit sets an output color value associated with a print position where the target-value Voronoi region and the measured-value Voronoi region are identical in the second color conversion table as the output color value associated with a specific input color value in the first color conversion table. The table generating unit sets the output color value associated with the print position where the target-value Voronoi region and the measured-value Voronoi region are different in the second color conversion table as a color value that is a color value in the hue plane and is different from the output color value associated with the specific input color value in the first color conversion table.

In one example in accordance with the present disclosure, a printing device is described. The printing device includes a print controller with a processor and memory. The print controller generates print instructions. Specifically, the print controller receives print image data representing an image to be printed and identifies enclosed regions in a background print agent plane. The print controller also determines a size of the enclosed regions of background print agent plane and responsive to the size of an enclosed region being smaller than a threshold size, removes the enclosed region from the background print agent plane. The printing device also includes a print agent distribution system to apply the background print agent and the image print agent to a substrate according to the print instructions.

An image shifter creates plural pairs of shift image data. A shading corrector and a halftone dot processor create halftone shift image data from shift images. Further, a difference image creator creates halftone common image data which is a common part of a pair of halftone shift image data, and creates halftone positive difference image data and halftone negative difference image data each of which is a difference between the halftone common image data and one of a pair of halftone shift image data. A composite image creator synthesizes the halftone common image data corresponding to an amount of positional deviation, and the halftone positive difference image data or halftone negative difference image data. A controller executes printing on web paper. Since the image data is only synthesized, processing load can be lightened even if printing is performed to restrain positional deviations.

A method for correcting tone-level non-uniformities in a digital printing system includes printing a test target having a set of uniform test patches. The printed test target is automatically analyzed to determine tone-level errors as a function of cross-track position for each of the test patches. A tone-level correction function is determined and represented using a set of one-dimensional feature vectors which specifies tone-level corrections as a function of cross-track position, pixel value and time. Corrected image data is determined by using the tone-level correction function to determine a tone-level correction value for each image pixel responsive to the input pixel value, cross-track position and time. The corrected image data is printed using the digital printing system to provide a printed image with reduced tone-level errors.

An image forming apparatus outputs a tone chart for calibration by a printer, reads the output tone chart by a scanner, determines whether data on a sheet is affected by a surface shape of the sheet based on the read tone chart, corrects data on a white area of the read chart based on a result of the determination, and executes calibration using the corrected data.