An image forming apparatus includes an image forming portion, a first acquisition processing portion, a second acquisition processing portion, and an adjustment processing portion. The image forming portion forms an image on a sheet. The first acquisition processing portion acquires a captured image of the sheet. The second acquisition processing portion acquires a specific value that indicates a difference between a gradation value of a pixel that, among pixels included in the captured image acquired by the first acquisition processing portion, corresponds to a higher part of an outer surface of the sheet, and a gradation value of a pixel that, among the pixels included in the captured image, corresponds to a lower part that is lower than the higher part. The adjustment processing portion adjusts an image forming condition of the image forming portion based on the specific value acquired by the second acquisition processing portion.

The image processing system includes a scanner, a pixelated photon detector (PPD), and at least one processor. The at least one processor displays a setting screen on a display unit. The setting screen is a screen for setting an identification range that is a range of gradation to be identified. The at least one processor displays a second image obtained by converting a first image on the display unit. The second image is an image obtained by converting the first image based on at least the identification range. The first image is generated based on an intensity signal of light detected by a PPD and a scanning position by the scanner.

An image processing apparatus includes an image analyzing unit, a tone-curve generating unit, and an image correcting unit. The image analyzing unit acquires a model parameter by modeling data distribution of an image with a probability distribution model. The tone-curve generating unit generates a tone curve on the basis of control information in which the model parameter acquired by modeling the data distribution of the image to be processed is associated with a target value of the model parameter. The image correcting unit corrects the image to be processed by using the generated tone curve.

An image forming apparatus outputs a tone chart for calibration by a printer, reads the output tone chart by a scanner, determines whether data on a sheet is affected by a surface shape of the sheet based on the read tone chart, corrects data on a white area of the read chart based on a result of the determination, and executes calibration using the corrected data.

Determination information is obtained to determine a degradation characteristic of sharpness of an image formed by an image forming apparatus. One of a plurality of recovery processing parameters used to recover sharpness of an image is selected based on the determination information, and characteristics of the plurality of recovery processing parameters are different from each other. Recovery processing of sharpness is performed on image data using the selected recovery processing parameter. When the degradation characteristics of sharpness are visually and substantially the same, the same recovery processing parameter is selected.

An image reading device includes: a scanner glass; photo-sensors arranged at intervals in a main scanning direction to read a document conveyed in a sub-scanning direction; an adjuster that adjusts the size of an overlapping area between a first and second image obtained by neighboring photo-sensors, the overlapping area constituting a first area of the first image and a second area of the second image; a superimposing portion that shifts either one of images of the first and second area to the other one; a judgment portion that judges whether the images having different focal depths exist based on the degree of matching between the first and second area; and a detector that detects a foreign body on the scanner glass platen by detecting a continuous image stretching in a document conveying direction in both of the images having different focal depths, if the images having different focal depths exist.

A non-transitory computer-readable medium stores computer-readable instructions. The instructions, when executed by a processor of an image processing apparatus, perform processes. The processes include registering, in a storage, a candidate color for each of a plurality of divided areas included in image data indicating an image on a sheet. The processes further include identifying, from among a plurality of pixels included in the image data, a target pixel based on a color value of the target pixel. The processes further include replacing the color value of the identified target pixel with a target color when a condition based on the color value of the identified target pixel and a color value of the target color is satisfied.

An image processing apparatus has a storage configured to store image data representing a color image, the image data being constituted by multiple pixels, each of the multiple pixels having a gradation value, and a controller. The controller is configured to extract pixels, from among the multiple pixels, within a specific color range as target pixels, adjust the gradation values of the target pixels such that brightness values of the target pixels are lowered, generate a histogram of index values corresponding to quantities of the brightness values of the multiple pixels constituting the image data after the gradation values of the target pixels are adjusted, set a first threshold value based on the histogram as generated, and apply a binarizing process to the image data using the first threshold value.

A document type recognition apparatus includes an image region separation unit, a smoothing unit, an edge enhancement unit, a histogram creation unit, and a document type recognition unit. The image region separation unit outputs a signal indicative of each region obtained by separating an input image into a character region and a pattern region. The smoothing unit performs smoothing processing to remove halftone dots of a particular number of lines or greater in the pattern region of the input image. The edge enhancement unit outputs an image subjected to edge enhancement processing depending on an amount of edge on an edge portion of the character region in the input image subjected to the smoothing processing. The histogram creation unit creates a histogram of the image subjected to the edge enhancement processing. The document type recognition unit recognizes a document type of the input image by utilizing the histogram.

A method, computer system, and a computer program product for image capture prevention is provided. The present invention may include, in response to embedding at least one digital security mark in a visual communication, securing the visual communication. The present invention may also include preventing, based on the embedded at least one digital security mark, an image capture of the secured visual communication.