Hewlett-packard Development Company, L.p.

Purdue Research Foundation

Yousun Bang

Kimin Kang

Yi Yang

Jan Philip Allebach

Mark Q Shaw

Seongwook Han

Minki Cho

Runzhe Zhang

Eunah Song

Ki-Youn Lee

Kiyoun Lee

According to examples, an apparatus may include a processor and a memory on which are stored computer-readable instructions that, when executed by the processor, may cause the processor to access a master image to be printed and receive a scanned image corresponding to the master image. The processor may identify a defect in a scanned image region of interest (ROI) based on the master image. A type of the scanned image ROI may include a raster ROI, a symbol ROI, a background ROI, and/or a color vector ROI, and the identified defect may be associated with the type of the scanned image ROI. The processor may determine a severity of the identified defect of the scanned image and may output the determined severity.

Image region of interest defect detection

An example operation method of an image forming apparatus includes forming a test image with respect to a pattern used for diagnosing an image-quality state of a printout output by the image forming apparatus, obtaining a test signal corresponding to the test image via a sensor of the image forming apparatus, obtaining image-quality state information indicating an image-quality state of the test image based on the test signal corresponding, identifying a type of a screen corresponding to halftone information indicating a resolution of the printout based on the image-quality state information, and performing a first image forming operation according to the type of the screen.

Identify type of screen according to image quality of image forming apparatus

In some examples, a device includes a printing device to generate an image on a substrate from a digital image, and a processor to: receive a scanned image of the image on the substrate, identify a plurality of image portions of the scanned image, identify horizontal color changes across a horizontal portion of the plurality of image portions, identify vertical color changes across a vertical portion of the plurality of image portions, compare the horizontal color changes and vertical color changes to corresponding horizontal color changes and corresponding vertical color changes of the digital image, and measure a presence of color plane misregistration, and the color, direction and magnitude of misregistration based on the comparison.

Color plane misregistration determinations

An image forming apparatus is provided. The image forming apparatus includes an image former to change a transfer condition while printing a calibration chart in which patches of different colors are repeatedly arranged in a sub-scanning direction, a scanner to scan the printed calibration chart, and a processor to determine an image defect under each transfer condition using the scanned calibration chart, and to set a transfer condition of the image former based on the determined image defect.

Calibration chart based image forming apparatus

Growing community of inventors

Pangyo, South Korea

Yousun Bang