A method is described in which a first color is detected at a user-selected arbitrary position of a first print; a second color is detected at a user-selected arbitrary position of a second print printed by a printer; a color difference between the first color and the second color is determined; and settings of the printer are changed to reduce the color difference in further prints printed by the printer.

System and methods for matching color and appearance of a target coating are provided herein. The system includes an electronic imaging device configured to receive a target image data of the target coating. The target image data includes target coating features. The system further includes one or more feature extraction algorithms that extracts the target image features from the target image data. The system further includes a machine-learning model that identifies a calculated match sample image from a plurality of sample images utilizing the target image features. The machine-learning model includes pre-specified matching criteria representing the plurality of sample images for identifying the calculated match sample image from the plurality of sample images. The calculated match sample image is utilized for matching color and appearance of the target coating.

The invention relates to a method for online quality control of decorative prints on substrate materials, including similarity comparisons of actual and target images and adjusting decorative prints if deviations of color values are detected. The method may include the steps of: a) producing a hyperspectral digital image of a print decoration; b) calibrating the print decoration via a hyperspectral digital image; c) producing and storing a digital target image of the print decoration; d) creating a first print decoration on a first substrate material; e) producing and storing a digital actual image of the printed decoration on the first substrate material; f) determining color deviations between the digital target image and the digital actual image via a computer program; and g) printing on at least one side of substrate materials so as to form a decorative layer. The invention also relates to a device for carrying out the method.

Processor implemented systems and methods for matching color and appearance of a target coating are provided herein. A system includes a storage device for storing instructions, and one or more data processors. The data processor(s) are configured to execute instructions to receive a target image of a target coating. The data processor(s) are also configured to apply a feature extraction analysis process that divides the target image into a plurality of target pixels for image analysis.

An image forming system may comprises an image forming unit, a sensor, and a controller. The controller configured to control the sensor based on measurement modes including a first measurement mode and a second measurement mode. A sampling number of an image by the sensor while the sensor moves in the direction orthogonal to the conveying direction in the first measurement mode is less than a sampling number of an image by the sensor while the sensor moves in the direction orthogonal to the conveying direction in the second measurement mode.

For determining a match factor regarding color match of a printed product with target values for colors, measuring fields of a printout are spectrally measured and actual measured values of the printout recorded. The target values are compared with actual measured values by determining for the printed product a color value axis from a unique color value as a start point to a second unique color value as end point and interpolation points between the first and second unique color values; determining target values for start and end points and interpolation points; determining actual measured values for start and end points and interpolation points of the printout from the actual measured values; determining a distance value representing the distance between target value and actual measured value for each start point, end point, and interpolation point; and calculating and outputting the match factor as statistical average of the distance values.

An image forming apparatus includes: a scanner to read each of a first output product serving as a model and a second output product output from the image forming apparatus; a memory that stores a color conversion lookup table to be used when color conversion is performed from a RGB color system into a CMYK color system; and circuitry to correct the color conversion lookup table based on a number of pixels and an amount of change per hue, using read information on the first output product, and re-correct the corrected color conversion lookup table, using read information on the second output product.

The invention provides a method and an apparatus for adopting analogue decor templates in decor printing, including a similarity comparison between at least one of (1) to n hyperspectral digital reference images of the analogue decor template and at least one of (1) to n hyperspectral digital actual images of a substrate with decor. A decor-specific profile target is adjusted such that the digital template of the analogue decor template can be output on a substrate by way of an output medium in such a way that the colour deviation between at least one of (1) to n reference images of the analogue decor template and at least one of (1) to n actual images of the substrate with decor is below a specified target value.

The application relates to a method for controlling a printing process for printing a decorative target image on a substrate, comprising providing the decorative target image to be printed in the printing process by at least one decorative parameter data set, simulating the printing process in a simulation step based on the decorative parameter data set, at least one printing process parameter data set and stored historical printing data sets, such that a digital decorative image is generated, verifying the generated digital decorative image based on the decorative target image to be printed and at least one verification criterion, and if the verification criterion is met, outputting the printing process parameter data set used in the simulation step for performing the printing process.

An illustrative image processing system extracts a first color-field image from an original color image associated with a set of color-field components. The first color-field image is associated with a first subset of the set of color-field components. The image processing system also extracts a second color-field image from the original color image. The second color-field image is associated with a second subset of the set of color-field components that is different from the first subset. The image processing system detects a first set of features within the first color-field image and a second set of features within the second color-field image. At least one feature is detected within the first color-field image and included in the first set of features while not being detected within the second color-field image or included in the second set of features. Corresponding methods and systems are also disclosed.