An image processing apparatus is equipped with: an image data receiving unit that receives image data; and a print data generating unit that generates multiple value data as print data by performing a halftone process on the image data and converting the image data into at least three values. The print data generating unit administers a halftone process that includes a density fluctuation suppressing process that results in the print data always including a zero value except for a case in which all of the pixels that constitute the image data are converted into a maximum value.

A method for encoding complex-valued signals of a computer-generated hologram into a phase-modulating optical element for the reconstruction of a three-dimensional object, and to a computer program product for encoding complex-valued signals of a computer-generated hologram, and to a holographic display for the reconstruction of a three-dimensional object. The object is to reduce the effort on encoding a complex-valued spatial distribution by an iteration method on the basis of phase encoding, so that the computer-generated hologram resulting therefrom can be represented more rapidly and with the same or an improved reconstruction quality. In particular, the convergence during the iterative optimization is intended to be accelerated. This is achieved by a method in which degrees of freedom of the hologram plane as well as the reconstruction plane are used for optimizing the iteration method for rapid convergence and maximization of the diffraction efficiency in the signal range.

System for presenting a digital art image comprising a server (1) and a digital art frame (2), wherein the digital art frame (2) comprises an electronic paper display, wherein the digital art frame (2) comprises a mounting means configured to fix the digital art frame (2) on a wall, wherein the server (1) is configured to store a plurality of dithered digital art images, wherein the processed digital art images have the same number of intensity levels as the electronic paper display (21), wherein the processed number of intensity levels is at least four, wherein the system is configured to transfer one of the processed digital art images to the digital art frame (2) and to display the transferred processed digital art image on the electronic paper display (21).

An information loss determiner in an image processing device determines whether character collapse has occurred in a simple binarized image. If character collapse has not occurred in the simple binarized image, an image processing determiner selects simple binarization processing as the image processing method of output image data. If character collapse has occurred in the simple binarized image, the process proceeds to photograph area size determination. If the ratio of a photograph area size is less than or equal to a predetermined value, the information loss determiner determines that character collapse has occurred in a posterization processed image. If character collapse has occurred in the posterization processed image, the image processing determiner selects grayscale processing. If character collapse has not occurred in the posterization processed image, the image processing determiner selects posterization processing.

A method of screening a continuous-tone image is configured to produce an output image to be printed on a surface. The continuous-tone image comprises a plurality of pixels having respective corresponding intended print locations. The method includes selecting a first sequence comprising a subset of the plurality of intended print locations, the first sequence being selected based on properties of the plurality of intended print locations. For each intended print location in the first sequence, the method also includes identifying the corresponding pixel in the continuous-tone image to obtain a second sequence for an error diffusion process comprising the identified corresponding pixels in the continuous-tone image.

There are disclosed techniques for error diffusion for printing. For example, there is disclosed a device comprising a pixel selector, to select a pixel from an image to be printed, wherein the pixel is associated to a group of device state probabilities, wherein each device state probability describes a probability of choosing a particular device state, wherein each device state describes the quantity of each colorant to be used in correspondence of the pixel. The device may comprise a device state determiner, to choose the device state for the selected pixel on the basis of the device state probabilities associated to the selected pixel. The device may comprise a feedback chain, to diffuse device state probability errors to pixels to be subsequently selected. The feedback chain may include a selected pixel error determiner, to determine device state probability errors for each device state probability of the selected pixel. The feedback chain may include a neighbouring pixel selector, to choose neighbouring pixels among the pixels to be subsequently selected. The feedback chain may include a neighbouring pixel error modifier, to modify, for each neighbouring pixel, the determined device state probability errors according to criteria conditioned by metrics and/or classification data associated to the selected pixel and/or a group of previously selected pixels and the relative position between the neighbouring pixel and the selected pixel. The feedback chain may include an error diffuser, to diffuse the modified device state probability errors to the neighbouring pixels.

An original image is divided in a primary scan direction, and an upstream overlapping segment that overlaps with the divided image on the upstream in the primary scan direction is provided from the division position. Halftone processors are provided in correspondence with the divided images, and the pixels on each raster line of each of the divided images are sequentially picked up as a pixel of interest, and an error diffusion method is applied to the pixel of interest. The halftone processor that processes the divided image on the downstream in the primary scan direction out of the plurality of divided images starts, after the halftone processor that processes the upstream divided image performs the halftone processing on a pixel on a raster line, halftone processing on a pixel on the raster line of the divided image to be processed and causes, in the halftone processing, the result of the halftone processing performed on the pixel of interest by a degree specified in advance with the result of halftone processing performed on the corresponding pixel in an upstream overlapping segment of the adjacent upstream divided image.

An image shifter creates plural pairs of shift image data. A shading corrector and a halftone dot processor create halftone shift image data from shift images. Further, a difference image creator creates halftone common image data which is a common part of a pair of halftone shift image data, and creates halftone positive difference image data and halftone negative difference image data each of which is a difference between the halftone common image data and one of a pair of halftone shift image data. A composite image creator synthesizes the halftone common image data corresponding to an amount of positional deviation, and the halftone positive difference image data or halftone negative difference image data. A controller executes printing on web paper. Since the image data is only synthesized, processing load can be lightened even if printing is performed to restrain positional deviations.

A method for encoding complex-valued signals of a computer-generated hologram into a phase-modulating optical element for the reconstruction of a three-dimensional object, and to a computer program product for encoding complex-valued signals of a computer-generated hologram, and to a holographic display for the reconstruction of a three-dimensional object. The object is to reduce the effort on encoding a complex-valued spatial distribution by an iteration method on the basis of phase encoding, so that the computer-generated hologram resulting therefrom can be represented more rapidly and with the same or an improved reconstruction quality. In particular, the convergence during the iterative optimization is intended to be accelerated. This is achieved by a method in which degrees of freedom of the hologram plane as well as the reconstruction plane are used for optimizing the iteration method for rapid convergence and maximization of the diffraction efficiency in the signal range.

An image processing apparatus generates and outputs a binarized output pixel value corresponding to an input pixel value; and includes a filter processing unit, a quantizer, and a buffer. The quantizer is configured to quantize a pixel value after a filter process performed by the filter processing unit and thereby generate the output pixel value. The buffer is configured to store for each pixel a difference between (a) a sum of the pixel value after the filter process and the input pixel value and (b) the output pixel value. Further, the filter processing unit performs a bandpass filter process on the basis of the difference stored by the buffer.