Canon Kabushiki Kaisha

Seita Shono

Akihiro Usami

Ken-ichi Ohta

Takashi Kawai

Eiji Ohta

Yoshiko Horie

Jun Koide

Hiroshi Kaburagi

Toshihiko Otsubo

Communication with an external image output device is established via a network interface, information concerning the characteristics of the image output devices is received and is held in a back-up RAM. A multilevel image containing gray-scale information enters from an input sensor pixel by pixel and is binarized to a binary image by a binarization circuit. At this time the connectivity of the binary image is controlled based upon the characteristic information held in the RAM and the binary image, the connectivity of which has been controlled, is transmitted to the external image output device via the network interface. As a result, the connectivity of the binary image is controlled to deal with a change in binary-image reproducibility caused by differences in engine characteristics of image output devices on a network and by changes in the environment and change with time, thereby making it possible to optimize connectivity, achieve stable reproduction and improve image quality.

Controlling dot connectivity in binarizing an image

An image recording apparatus includes at least one recording head, in which a plurality of solid-state recording elements are arranged, for performing image recording by causing each of the plurality of solid-state recording elements to record a pixel, a storage unit for storing correction data for correcting image data in accordance with a recording characteristic of each of the plurality of solid-state recording elements so as to correspond to the corresponding one of the plurality of solid-state recording elements. Each of the plurality of solid-state recording elements is driven in accordance with input image data and the correction data stored in the storage unit. The apparatus also includes a pattern-data generation unit for generating predetermined pattern data, and for causing each of a predetermined number of consecutive solid-state recording elements from among the plurality of solid-state recording elements to record a pixel based on the predetermined pattern data, a reading unit for reading a test pattern recorded by the recording head based on the pattern data generated by the pattern-data generation unit, an acquisition unit for acquiring the recording characteristic of each of the plurality of solid-state recording elements based on a ratio of a number of solid-state recording elements which have recorded pixels in accordance with the predetermined test pattern to a number of pixels of the test pattern read by the reading unit, and a changing unit for changing the correction data for each of the solid-state recording elements in accordance with the recording characteristic of the corresponding one of the solid-state recording elements acquired by the acquisition means. The image recording apparatus can exactly detect the recording characteristic of each of the plurality of solid-state recording elements, and prevent nonuniformly in density caused by individual difference in the recording characteristic during image recording.

Image recording apparatus and copying system

In order to stabilize image quality in both a copier mode and a printer mode without placing a significant burden on a user, there is provided an image forming apparatus including a reading device for reading an original document and producing first image signals; an input device for inputting second image signals from an external apparatus; an image forming device for forming an image on a recording medium on the basis of the first and second image signals produced by the reading device and input by the input device, respectively; a calibration device for calibrating image processing conditions corresponding to image forming characteristics in a copier mode; and a production device for producing image processing conditions in a printer mode on the basis of the calibrated image processing conditions, wherein the image forming apparatus has the copier mode in which an image is formed by using the reading device and the image forming device and the printer mode in which an image is formed by using the input device and the image forming device.

Image forming apparatus, image processing method, and recording medium

Adders (103, 104) add errors to multi-level image data whose number of bits is reduced by quantization units (101, 102), respectively. Weighted averaging units (120, 121) obtain the weighted average values of binary data of peripheral pixels which have already been divided, respectively. Comparators (107, 108) binarize, on the basis of the weighted average values, the image data output from the adders (103, 104) to obtain binary data corresponding to two pixels obtained upon dividing one pixel of the multi-level data into two pixels. Subtracters (105, 106) obtain the differences between the image data output from the adders (103, 104) and the weighted average values, respectively. Error arithmetic units (109, 110) obtain, on the basis of the differences, errors to be added by the adders (103, 104), respectively. Therefore, when one pixel of multi-level data is divided into two pixels of binary data, a binary image having a high resolution and high gradation can be generated at a low cost.

Image processing apparatus and method

An image conversion apparatus for image-converting input color image signals, and outputting the converted signals to an output apparatus, allows execution of a plurality of different color processing operations, checks if an input color image falls within a color reproduction region of the output apparatus, and changes the color conversion processing result to be output depending on whether or not the input color image falls within the color reproduction region of the output apparatus. For example, when the input color image falls within the color reproduction region of the output apparatus, color reproduction color-matched with input color image signals is performed. When the input color image falls outside the reproduction region, color reproduction is performed by color conversion processing assuring highest color reproducibility.

Color image processing apparatus

An image reading apparatus measures, color by color, an average transmission-density signal based upon image information obtained from a color original through which light is transmitted, converts the measured average transmission-density signal of every color into a subject-lightness signal of every color, and effects a conversion into a reference color stimulus signal, which is indicated by the apex of a triangle substantially circumscribed by a spectrum locus of a predetermined chromaticity diagram, based upon the converted subject-lightness signal of every color.

Image reading apparatus

Image processing system for performing color image data calibration

Disclosed is a binarization method for binarizing multi-level image data of an object pixel in accordance with binarized data of neighboring pixels of the object pixel which have been binarized. Multi-level image data corresponding to an object pixel are input, then a first portion of the input data is binarized in accordance with a random number, and a second portion of the data is binarized in accordance with the binarized data. The binary data of the first portion and the binary data of the second portion are output as binary data of the object pixel.

Image processing apparatus

An image processing apparatus, which stochastically binary-converts lower-bit data of a pixel of interest to improve image quality in a highlight portion, as well as in a low-density portion, is provided. In an image processing apparatus for quantizing multi-value image data to binary data, multi-value image data of a pixel of interest is divided into upper- and lower-bit data by a calculator (24). The lower-bit data is binary-converted by a comparator (25) using a normalized uniform random number generated by a random number generator (26) as a threshold value. The binary-converted data is added to the upper-bit data of the image signal of the pixel of interest by an adder (22), and the sum data is binary-converted by a comparator (18) using one of a plurality of weighted average values of a plurality of pixels near the pixel of interest, which values are calculated by a calculator (600), on the basis of binary data of pixels, which have already been binary-converted before the pixel of interest. At this time, the density is preserved by distributing a density error generated upon binary conversion to non-binary-converted pixels near the pixel of interest by a circuit including a subtracter (17), an adder (22), and the like.

Image processing capable of handling multi-level image data without

Interpolation processing is applied to the output of a look-up table in which a correlation between color-separation signals and density signals ideal for these color-separation signals are stored, with a quantization error produced when quantizing the color-separation signals being adopted as an interpolation coefficient. The quantization and the interpolation processing are executed in a uniform color space.

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Warabi, Japan

Seita Shono