a method for correcting an error in image printing, the method includes receiving a reference digital image (RDI). Based on a predefined selection criterion, one or more regions in the RDI that are suitable for use as anchor features for sensing the error, are selected. A digital image (DI) acquired from a printed image of the RDI, is received and the one or more regions are identified in the DI. Based on the anchor features of the DI, the error is estimated in the printed image. A correction that, when applied to the DI, compensates for the estimated error, is calculated. The estimated error is corrected in a subsequent digital image (SDI) to be printed, and the SDI having the corrected error, is printed.

A printing apparatus includes a print execution section and a controller. The print execution section includes: a printing head having nozzles from which ink is discharged; a main-scan section configured to execute main-scan in which the printing head moves along a main-scan direction relative to a printing medium; and a sub-scan section configured to execute sub-scan in which the printing medium moves along a sub-scan direction relative to the printing head. The controller obtains object image data indicating an object image formed by pixels, generates pieces of partial printing data by processing the object image data in an order from a downstream side toward an upstream side in the sub-scan direction, and causes the print execution section to execute, a plurality of times, the sub-scan and partial printing in which ink is discharged from the printing head during the main-scan by use of the pieces of partial printing data.

An image forming apparatus includes an image forming device, a reading device, and circuitry. The image forming device discharges ink droplets through nozzles to form an image on a recording medium conveyed in a first direction. The reading device reads the image formed on the recording medium. The circuitry generates a correction chart that includes patches, located in the first direction and representing different densities from each other, and two marks located at different positions from each other in a second direction perpendicular to the first direction. The circuitry locates opposed end portions of the patches in the second direction outside the two marks in the second direction. The circuitry derives correction data, based on read data of an area of the patches existing inside the two marks in the second direction included in read data provided by the reading device reading the correction chart formed on the recording medium.

Examples of methods are described herein. In some examples, a method includes calculating a first cost function measure based on band defects in an image. In some examples, the method also includes calculating a second cost function measure based on the band defects and a synthetic band. In some examples, the method further includes detecting a missing band based on a comparison of the first cost function measure and the second cost function measure.

A redundantly printed security-enhanced document, printing method, and system for better ensuring that the meaning of the information imparted by variable indicia printed by redundant printing indicia on a document protected by a removable Scratch-Off Coating (SOC). By printing the variable indicia with multiple colors, redundancy and integrity of the intended indicia is achieved relative to the perception of human eye photoreceptor cones. The redundantly printed document, methods, and systems enhance the overall appearance of the redundantly printed document, and reduce possible consequences resulting from misprinted variable indicia.

A method of digital printing is disclosed in which a digital image to be printed has at least one region having pixels comprising superpositioned layers of a first ink and a second ink. The method includes producing at least one sample print and calibrating misalignment of the superpositioned layers at a plurality of calibration locations on the sample print. The resultant misalignment data is provided to a morphing program to determine a pre-deformation of the digital image to compensate for misalignment during printing. An apparatus and a machine-readable storage medium comprising instructions executable by a processor are also disclosed.

Examples of methods are described herein. In some examples, a method includes calculating a first cost function measure based on band defects in an image. In some examples, the method also includes calculating a second cost function measure based on the band defects and a synthetic band. In some examples, the method further includes detecting a missing band based on a comparison of the first cost function measure and the second cost function measure.

There is provided an image forming apparatus that forms an image with a plurality of coloring materials on a recording medium, and the image forming apparatus includes: a hardware processor that calculates a chromaticity range having a color difference not less than a setting value to respective chromaticities of the plurality of coloring materials for use in formation of the image, as a base color range common between the plurality of coloring materials.

a method for correcting an error in image printing, the method includes receiving a reference digital image (RDI). Based on a predefined selection criterion, one or more regions in the RDI that are suitable for use as anchor features for sensing the error, are automatically selected. A digital image (DI) acquired from a printed image of the RDI, is received and the one or more regions are automatically identified in the DI. Based on the anchor features of the DI, the error is automatically estimated in the printed image. A correction that, when applied to the DI, compensates for the estimated error, is calculated. The estimated error is corrected in a subsequent digital image (SDI) to be printed, and the SDI having the corrected error, is printed.

An example marking device may include a sensing device, a media conveyance component, and a controller. The sensing device may be arranged in a media path to sense data encoded on media. The media conveyance component may feed a medium into the media path and advance the medium a first distance less than a length of the medium. And the controller may receive timing signals indicative of read timing markings from the sensing device, receive data signals indicative of media characteristic markings from the sensing device, and alter marking parameters of the marking device based on the to be received data signals.