An image forming apparatus includes a table generating unit. The table generating unit determines whether a target-value Voronoi region and a measured-value Voronoi region are identical or not. The table generating unit sets an output color value associated with a print position where the target-value Voronoi region and the measured-value Voronoi region are identical in the second color conversion table as the output color value associated with a specific input color value in the first color conversion table. The table generating unit sets the output color value associated with the print position where the target-value Voronoi region and the measured-value Voronoi region are different in the second color conversion table as a color value that is a color value in the hue plane and is different from the output color value associated with the specific input color value in the first color conversion table.

An image processing apparatus includes a memory and processing circuitry electrically coupled to the memory. The processing circuitry is configured to correct image data in a section of an abnormal image, based on information that indicates a position of the section in an abnormal line image that is included in a received image. The processing circuitry is configured to output the corrected image data.

An image processing apparatus includes a memory and processing circuitry electrically coupled to the memory. The processing circuitry is configured to correct image data in a section of an abnormal image, based on information that indicates a position of the section in an abnormal line image that is included in a received image. The processing circuitry is configured to output the corrected image data.

An image forming device, includes: a body that processes a print job and discharges a printing sheet; a post-processing device that may be connected or detached from the body, and a hardware processor. The hardware processor performs: determining whether or not a sheet type indicated by the print job may be post-processed by the post-processing device; guiding a user to detach the post-processing device from the body when the sheet type indicated by the print job may not be post-processed by the post-processing device; detecting a distance between the post-processing device and the body when the post-processing device is detached from the body; and allowing a processing of print job when the detected distance is greater than an interval that enables the processing of the print job if the sheet type indicated by the print job may not be post-processed by the post-processing device.

An image forming apparatus includes a table generating unit. The table generating unit determines whether a target-value Voronoi region and a measured-value Voronoi region are identical or not. The table generating unit sets an output color value associated with a print position where the target-value Voronoi region and the measured-value Voronoi region are identical in the second color conversion table as the output color value associated with a specific input color value in the first color conversion table. The table generating unit sets the output color value associated with the print position where the target-value Voronoi region and the measured-value Voronoi region are different in the second color conversion table as a color value that is a color value in the hue plane and is different from the output color value associated with the specific input color value in the first color conversion table.

A method of measuring a display delay time includes a step where a display pattern displayed on a first display including i (i is a natural number greater than 2) display elements is switched to a display pattern other than the display pattern at every elapse of a pattern continuation time, and j (j is a natural number, 1<j<i) display elements brought into a first display state is switched at every elapse, a step where an image of the display pattern on the first display is captured, a step where the captured image is displayed on a second display, and a step where the display delay time from capturing the image on the first display to displaying the image on the second display is measured based on a difference between the display pattern on the first display and the display pattern on the second display.

A method of measuring a display delay time includes a step where a display pattern displayed on a first display including i (i is a natural number greater than 2) display elements is switched to a display pattern other than the display pattern at every elapse of a pattern continuation time, and j (j is a natural number, 1<j<i) display elements brought into a first display state is switched at every elapse, a step where an image of the display pattern on the first display is captured, a step where the captured image is displayed on a second display, and a step where the display delay time from capturing the image on the first display to displaying the image on the second display is measured based on a difference between the display pattern on the first display and the display pattern on the second display.

A method of measuring a display delay includes a first step where a first display device performs a switching operation of switching a display pattern displayed on a display unit of the first display device, a second step where a first camera captures a first image and displays the first image in a live view mode, a third step where a second camera captures a second image containing the first image and records at least the first image contained in the captured second image while being correlated with information indicative of an imaging time when the second image is captured, and a fourth step where a display delay time of the first camera from the imaging of the first image to the display of the first image is deduced from the time indicated by the display pattern contained in the first image and the information indicative of the imaging time.

A method of measuring a display delay includes a first step where a first display device performs a switching operation of switching a display pattern displayed on a display unit of the first display device, a second step where a first camera captures a first image and displays the first image in a live view mode, a third step where a second camera captures a second image containing the first image and records at least the first image contained in the captured second image while being correlated with information indicative of an imaging time when the second image is captured, and a fourth step where a display delay time of the first camera from the imaging of the first image to the display of the first image is deduced from the time indicated by the display pattern contained in the first image and the information indicative of the imaging time.

A method of measuring a shutter time lag of a camera includes: a first step of switching a display pattern of a display unit including i (i is a natural number greater than 2) display elements to a different display pattern at every time TP, and in the first step, the number of j (j is a natural number, and 1<j<i) display elements to be brought into a first display state among i display elements is switched at every time TP; a second step of capturing an image of the display unit in response to a shutter operation of the camera performed in synchronization with the switching operation; and a third step of deducing a shutter time lag taken from the shutter operation to the imaging of the display unit from the image captured by the camera.