An image forming apparatus that prints an adjustment pattern on a sheet includes a generator and an image former. The adjustment pattern is for correcting a color value obtained by reading a second patch region on the sheet with a second reader based on a color value obtained by reading a first patch region on the sheet with a first reader. The generator generates image data of the adjustment pattern, and the image former performs printing based on the image data. The adjustment pattern includes a first patch printed in the first patch region and a second patch printed in a region other than the first patch region in the second patch region. The second patch includes a common color patch in a same color as a color of the first patch, and a size of the first patch is larger than a size of the second patch.

In accordance with a user operation, an apparatus obtains one or more designated positions on an image, the one or more designated positions being one or more positions at which each of one or more designated colors designated for printing of the image is to be printed. The apparatus generates a printing file for causing a printer to print a patch of each of the one or more designated colors on a sheet at a position corresponding to each of the one or more designated positions for the designated color. The apparatus performs color verification based on a colorimetry value on the sheet having the patch printed thereon at the position corresponding to each of the one or more designated positions and a target value for the designated color corresponding to the designated position.

An image forming apparatus performs the following. An imaging range imaged by each of the plurality of imaging sensors includes an overlapping portion between the imaging sensors adjacent in a width direction orthogonal to a conveying direction along the conveying path. A hardware processor performs a calibration operation of a first sensor based on a color measuring result of a predetermined inspection image measured within a standard imaging range of the first sensor among the plurality of imaging sensors, and a standard imaging result within the standard imaging range imaging an inspection image with a same pattern as the inspection image. The hardware processor compares imaging results by the plurality of imaging sensors in the overlapping portions and performs the calibration operation of another sensor different from the first sensor using the standard imaging result as a standard.

In some examples, a printing device component includes a memory device comprising compressed coefficients that, when decompressed by a printing device, form difference entries, wherein a difference entry of the difference entries represents a difference of a value of a corresponding entry of a halftone table and a value of a corresponding entry of a reference table. The memory device further includes healing parameter values specifying a healing process to apply to a reconstructed halftone table produced using the coefficients.

Described are processes for preparing substituted imidazo[1,2-a]pyrazine compounds of formula (I): ##STR00001##
by reacting a compound of formula (xi): ##STR00002##
with carbonyldiimidazole to form the compound of formula (I).

A printing system is disclosed. The printing system includes at least one physical memory device to store halftone calibration logic and one or more processors coupled with the at least one physical memory device to execute the halftone calibration logic to receive print image measurement data corresponding to a first halftone design associated with each of a plurality of pel forming elements, generate measurement data for each of the pel forming elements based on the print image measurement data, generate a uniformity compensated halftone for each of the pel forming elements based on inverse transfer functions corresponding to each of the pel forming elements and the first halftone design and transmit the uniformity compensated halftone for each of the pel forming elements.

An image forming apparatus that prints an adjustment pattern on a sheet includes a generator and an image former. The adjustment pattern is for correcting a color value obtained by reading a second patch region on the sheet with a second reader based on a color value obtained by reading a first patch region on the sheet with a first reader. The generator generates image data of the adjustment pattern, and the image former performs printing based on the image data. The adjustment pattern includes a first patch printed in the first patch region and a second patch printed in a region other than the first patch region in the second patch region. The second patch includes a common color patch in a same color as a color of the first patch, and a size of the first patch is larger than a size of the second patch.

An object is to save a user's trouble in a case of printing correction charts and stabilization charts and performing automatic tone correction with the correction charts among the printed charts. An image processing apparatus performs: control for printing correction chart images along with identification images for respectively identifying the correction chart images on print media in a one-to-one correspondence; and control for printing a stabilization chart image on a print medium before the control for printing the correction chart images. Then, from among scan images obtained by reading correction charts and one or more stabilization charts, the apparatus identifies the scan images respectively corresponding to the correction charts based on the identification images appearing in the scan images, the correction charts each being obtained by printing a correction chart image along with the corresponding identification image, the stabilization charts each being obtained by printing the stabilization chart image.

A system is disclosed. The 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 receive an image having a blended input color comprising a first primary color value and a second primary color value, generate blend weights for the blended input color based on the first primary color value and the second primary color value, receive a plurality of transfer functions corresponding to each of the first primary color value and the second primary color values and apply the blend weights and the plurality of transfer functions to the first primary color value and the second primary color value to generate a uniformity corrected first primary color value and a uniformity corrected second primary color value associated with the blended input color.

A method of printing improved printed products using defect-free printing machine nozzles and compensated defective nozzles includes printing products and a test chart with test fields onto a transported substrate, the test fields having tonal values, every test field including an unprinted line from a nonactivated, nonprinting nozzle compensated by a neighboring nozzle having a compensation value, pairs of tonal value and compensation value being specified and used for the chart, recording an image of the chart, computer-analyzing the image and determining the compensation value. Every pair of tonal value and compensation value is used multiple times in the chart and a corresponding number of spaced apart test fields is created. A characteristic value representing test field homogeneity and determining compensation value quality is assigned to every measuring field. The best characteristic value regarding a specified criterion and the compensation value is determined for every tonal value.