Abstract: In an example, a method comprises: receiving, at a raster image processor, image data representing a print job, the image data representing an area to be printed using a process color separation and an area to be printed using a spot color; producing at the raster image processor, a first rasterized image representing a layer of the print job having the process color and a second rasterized image representing a layer of the print job having the spot color; receiving at an emulator, the second rasterized image; and representing, by the emulator, the second rasterized image as a plurality of constituent process color separation layers.

Abstract: An example of printing calibration includes printing a calibration page having test patches, the test patches developed at a plurality of voltages of a binary ink developer. The test patches are measured to determine an indication of ink thickness of the patches and a calibration voltage is generated based on the indications of the ink thickness of the test patches.

Abstract: Measures for use in calibrating a printing device. Historical dot gain linearization lookup table data for the printing device is processed. On the basis of the processed historical dot gain linearization lookup table data, a plurality of input points for a current dot gain linearization lookup table are dynamically determined. The printing device is calibrated according to the dynamically determined current dot gain linearization lookup table.

Abstract: Examples of charging a photoconductive layer in an image forming apparatus are described. In one example, a method includes applying a charging voltage to the photoconductive layer and measuring surface voltages of the photoconductive layer at a plurality of positions on the photoconductive layer. Based on the measured surface voltages, a correction voltage profile is determined. The determined correction voltage profile includes at least a first correction voltage associated with a first position on the photoconductive layer and a second correction voltage associated with a second position, different to the first position, on the photoconductive layer. The method includes applying the first correction voltage to the photoconductive layer and applying the second correction voltage to the photoconductive layer.

Abstract: A method of adjusting an imaging apparatus comprises printing a set of test patches, the set of test patches comprising a solid color patch, a grey level patch and a substrate patch. The optical densities of the set of test patches are determined. The method comprises simultaneously correcting a solid optical density value (Solid OD), relating to the solid color patch and an associated grey level (LUT) value relating to the grey level patch.

Abstract: In one embodiment, a processor-readable medium stores code representing instructions that when executed by a processor cause the processor to print a print job, and determine target color data for each sheet of the print job while printing the job. The instructions further cause the processor to continually save the target color data to a server for each sheet of the print job as each sheet is printed.

Abstract: Measures for use in calibrating a printing device. Historical dot gain linearization lookup table data for the printing device is processed. On the basis of the processed historical dot gain linearization lookup table data, a plurality of input points for a current dot gain linearization lookup table are dynamically determined. The printing device is calibrated according to the dynamically determined current dot gain linearization lookup table.

Abstract: An apparatus to calibrate a printer. The apparatus comprises a controller to: control deposition of white printing material on media, the white printing material having an opacity of at least 55%; control deposition of non-white printing material on the white printing material; receive data for at least one sensed characteristic of the non-white printing material; and calibrate the printer using the received data for the at least one sensed characteristic of the non-white printing material.

Abstract: Examples of charging a photoconductive layer in an image forming apparatus are described. In one example, a method comprises applying a charging voltage to the photoconductive layer and measuring surface voltages of the photoconductive layer at a plurality of positions on the photoconductive layer. Based on the measured surface voltages, a correction voltage profile is determined. The determined correction voltage profile comprises at least a first correction voltage associated with a first position on the photoconductive layer and a second correction voltage associated with a second position, different to the first position, on the photoconductive layer. The method comprises applying the first correction voltage to the photoconductive layer and applying the second correction voltage to the photoconductive layer.

Abstract: A method of adjusting an imaging apparatus comprises printing a set of test patches, the set of test patches comprising a solid color patch, a grey level patch and a substrate patch. The optical densities of the set of test patches are determined. The method comprises simultaneously correcting a solid optical density value (Solid OD), relating to the solid color patch and an associated grey level (LUT) value relating to the grey level patch.

Abstract: A printer (300) is disclosed. The printer has two scanners (336, 338) in the paper path of the printer located after the print zone (346). The two scanners are spaced apart from each other by a known distance A and overlap each other in a direction perpendicular to the media axis of travel. The two scanners capture a first and second image of the media.

Abstract: A spectrophotometer diagnosis system and a method for diagnosing a spectrophotometer, wherein at least one test patch is printed in proximity to at least one non-printed substrate patch, at least one value characteristic of the at least one test patch and/or the at least one substrate patch is measured using the spectrophotometer, and at least one diagnostic score for the spectrophotometer is determined based on the at least one measured value in comparison with a reference value.

Abstract: In one embodiment, a processor-readable medium stores code representing instructions that when executed by a processor cause the processor to print a print job, and determine target color data for each sheet of the print job while printing the job. The instructions further cause the processor to continually save the target color data to a server for each sheet of the print job as each sheet is printed.

Abstract: A method includes forming a second set of printing dots on a photosensitive member by a printing dot applicator corresponding to image data of second portions of the image adjacent to first portions of the image. The second set of printing dots are formed on the photosensitive member after the first set of printing dots have been transferred from the photosensitive member. Thus, a merging of adjacent printing dots due to an electrical interaction there between on the photosensitive member is reduced.

Abstract: In one embodiment, a processor-readable medium stores code representing instructions that when executed by a processor cause the processor to print a print job, and determine target color data for each sheet of the print job while printing the job. The instructions further cause the processor to continually save the target color data to a server for each sheet of the print job as each sheet is printed.

Abstract: An apparatus to calibrate a printer. The apparatus comprises a controller to: control deposition of white printing material on media, the white printing material having an opacity of at least 55%; control deposition of non-white printing material on the white printing material; receive data for at least one sensed characteristic of the non-white printing material; and calibrate the printer using the received data for the at least one sensed characteristic of the non-white printing material.

Abstract: In one embodiment, a processor-readable medium stores code representing instructions that when executed by a processor cause the processor to print a print job, and determine target color data for each sheet of the print job while printing the job. The instructions further cause the processor to continually save the target color data to a server for each sheet of the print job as each sheet is printed.

Abstract: A spectrophotometer diagnosis system and a method for diagnosing a spectrophotometer, wherein at least one test patch is printed in proximity to at least one non-printed substrate patch, at least one value characteristic of the at least one test patch and/or the at least one substrate patch is measured using the spectrophotometer, and at least one diagnostic score for the spectrophotometer is determined based on the at least one measured value in comparison with a reference value.

Abstract: An apparatus to calibrate a printer. The apparatus comprises a controller to: control deposition of white printing material on media, the white printing material having an opacity of at least 55%; control deposition of non-white printing material on the white printing material; receive data for at least one sensed characteristic of the non-white printing material; and calibrate the printer using the received data for the at least one sensed characteristic of the non-white printing material.

Abstract: In one embodiment, a processor-readable medium stores code representing instructions that when executed by a processor cause the processor to print a print job, and determine target color data for each sheet of the print job while printing the job. The instructions further cause the processor to continually save the target color data to a server for each sheet of the print job as each sheet is printed.