An evaluation device evaluates an image clarity of a print image. The evaluation device includes: an object that is projected onto a measurement surface of a recording medium; an illuminator that makes the object projected onto the measurement surface; an imager that images the measurement surface on which the object has been projected to obtain image data; and a hardware processor that, based on a distribution of parameters related to a brightness of the image data, quantifies a degree of the image clarity into a numerical value and defines the numerical value as an evaluation value of the image clarity.

An image forming apparatus 100, which carries out constant-voltage control of a voltage applied to a transfer member 8 and is capable of executing limiter control for controlling the voltage applied to the transfer member 8 based on a detection result of a current detecting portion 21 so that the detection result falls within a predetermined range, is capable of executing a first mode in which a toner image is transferred onto a recording material P and a second mode in which a plurality of test toner images are transferred onto the recording material P by applying a plurality of different voltages to the transfer member 8, and a controller 50 is capable of carrying out the limiter control while the recording material P passes through the transfer portion 8 in executing the first mode and does not carry out the limiter control while an area onto which the plurality of test images are transferred passes through a transfer portion N2 in executing the second mode.

An image reading apparatus includes a transparent member, a conveyance unit, a reading unit reading an image information through the transparent member from the sheet conveyed by the conveyance unit, and a guide member provided upstream of a reading position where the reading unit reads the image information from the sheet with respect to a sheet conveyance direction. The guide member includes a sheet-like sheet member having elasticity. A leading end of a downstream side of the guide member in the sheet conveyance direction is a folded portion formed by folding back the sheet member.

An image forming system cyclically conveys an Nth sheet with an image formed on a first side to an image forming unit as a sheet subject to image formation after image formation on a subsequent (N+i)th sheet, and form an image on a second side of the Nth sheet. The system includes an obtaining unit that, during image forming processes, obtains respective updated adjustment values for the first and second sides, and a control unit that performs control to simultaneously store the updated adjustment value for the first side and an unupdated adjustment value for the second side in a part of a period of the processes, form an image on the first side of the (N+i)th sheet using the updated one for the first side, and form the image on the second side of the Nth sheet using the unupdated one for the second side.

In an example method, an image of a printed document is descreened. The descreened image is separated into blocks. A smooth area of the descreened image is selected based on an averaging of localized color distance values of pixels in each of the blocks. A streak in a block of the smooth area is detected in response to detecting that a magnitude of a color distance projection of the block exceeds a threshold value.

A printing system includes a product inspection unit configured to perform product inspection on a print product based on a scanned image generated by reading the print product with an image printed thereon and correct answer images stored in advance, a post-processing unit configured to perform post-processing on the print product, and a control unit configured to, upon occurrence of a jam in the print product, control the printing unit to perform reprinting, wherein, upon occurrence of a jam while the post-processing is performed, the product inspection unit is notified of identification information regarding the print product on which printing is started by the reprinting, and wherein, based on the identification information, the product inspection unit references any of the correct answer images corresponding to a scanned image generated by the reprinting and performs the product inspection on the print product.

To provide an image forming apparatus capable of achieving both correction accuracy of skew correction and minimization of a margin between images.

A color shift amount calculator that calculates a color shift amount, and a first skew correction controller and a second skew correction controller that control skew correction of color shift are included. The first skew correction controller controls first skew correction by a mechanical operation by the image former on the basis of a first color shift residual target value set in advance. The second skew correction controller controls second skew correction, by image processing, of the color shift after the control by the first skew correction controller on the basis of a second color shift residual target value set in advance.

An image forming apparatus forms a color image on a recording medium by superimposing images of colors formed by image forming units. The apparatus includes a processor that: acquires a read image by reading the recording medium on which the color image has been formed; forms a register patch outside a job image forming region of the recording medium; and corrects image forming positions of the image forming units based on the read image that includes the register patch. The register patch includes: a leading end patch and a rear end patch formed with a reference color material; and one or more measurement target color patches formed with measurement target color materials between the leading end patch and the rear end patch. The hardware processor corrects the image forming positions based on relative positions of the leading end patch, the rear end patch, and the measurement target color patches.

An image formation apparatus includes: an image former that prints an image on paper; a corrector that corrects a print position of the image on the paper; and a first sensor that is disposed on a conveyance path upstream of the image former, detects paper, and outputs detection data to the corrector, wherein the corrector obtains, on the basis of the detection data, an amount of change in a shape of first paper from a shape of second paper printed before the first paper is printed, and corrects a print position of a first image on the first paper on the basis of the change amount.

An image forming apparatus includes an image forming unit configured to form an image on a sheet based on image forming condition, a reader configured to convey the sheet and read a test image on the sheet while the sheet is conveyed, and a controller configured to control the image forming unit to form the image and the test image on a same sheet, control the reader to read the test image on the same sheet, and generate the image forming condition for adjusting a density of an image to be formed by the image forming unit, based on a reading result of the test image by the reader.