A computer-implemented method for generating an amplitude modulated multi-cluster halftone dot for use in an amplitude modulated screen includes determining an arrangement of clusters within the dot; determining a cluster function for each cluster, the cluster function defining a pixel sequence indicating a sequence of turning on device pixels within an area of a particular cluster; determining a dot function for the dot, the dot function defining a cluster sequence indicating a sequence of the clusters; and generating a set of data representative of the dot for a particular tonal value, by determining the device pixels within the dot turned on for that particular tonal value according to the cluster functions and the dot function. A computer program, a printing device and a printed product are also provided.

A printing system is disclosed. The printing system includes at least one physical memory device to store halftone calibration logic and one or more processors coupled with the at least one physical memory device to execute the halftone calibration logic determine an uncalibrated deposition distribution for each of a plurality of pel forming elements, determine a calibrated deposition distribution for each of the plurality of pel forming elements and determine calibration values for each of the plurality of pel forming elements.

An image processing apparatus includes a comparison unit and a control unit. The comparison unit compares a light-dark pattern of a plurality of pixels of an input image with a previously-stored pattern to determine a semitransparent object. The plurality of pixels include a pixel of interest and peripheral pixels thereof. The control unit changes intensity of edge correction processing to be applied to the pixel of interest in at least three levels based on a result of the comparison by the comparison unit.

For a dither matrix used when converting multivalued data into image data for an output apparatus, thresholds are set such that: a first dot and a second dot alternately become larger until both of the first dot and the second dot reach a first dot size; after both of the first dot and the second dot reach the first dot size, the first dot becomes larger until the first dot reaches a second dot size while the second dot does not become larger, and thereafter, the second dot becomes larger until the second dot reaches the second dot size while the first dot does not become larger; and after both of the first dot and the second dot reach the second dot size, the first dot and the second dot alternately become larger.

An image processing apparatus includes a multi-gradation-level dither processing unit and a screen processing unit. The multi-gradation-level dither processing unit performs a multi-gradation-level dither process for a target image. The screen processing unit performs an FM screen process for the target image for which the multi-gradation-level dither process has been performed. Further, in the multi-gradation-level dither process, the multi-gradation-level dither processing unit selects each pixel in the target image as a target pixel in turn; using a conversion characteristic corresponding to each local pixel position group in a unit matrix, converts a pixel value of the target pixel to one of: a minimum gradation level, a maximum gradation level and an intermediate gradation level corresponding to the pixel value of the target pixel; and sets a pixel value of each pixel in the unit matrix as a pixel value obtained with the conversion characteristic.

A method for manufacturing a security document including a security pattern generation method includes the steps of selecting a bounding region, an image object, and a raster image or a function; cutting the image object into image object partitions; and repeating the image object as a pattern, preferably a lattice pattern, in the bounding region wherein each of the image object partitions of an image object is transformed depending on the position area of the image object in the lattice pattern and the rank of the image object partition.

The image processing apparatus of the present invention includes: an image data acquisition unit configured to acquire image data; a generation unit configured to generate an ejection pattern of ink droplets from the image data, which are ejected for forming dots from a plurality of nozzles of an image forming apparatus; a characteristic acquisition unit configured to acquire an ejection characteristic of ink droplets of the image forming apparatus; and a pattern change processing unit configured to change the ejection pattern based on the ejection characteristic and the ejection pattern, and the pattern change processing unit repeatedly performs, in a case where a gap occurs between dots that should be formed so as to contact each other by the image forming apparatus, the ejection pattern change until the gap is eliminated.

The image processing apparatus of the present invention includes: a first memory configured to store a first threshold value matrix used for halftone processing; a second memory configured to store a second threshold value matrix that is a threshold value matrix used for halftone processing and whose size is larger than the first threshold value matrix; and at least one circuit, the at least one circuit causing processing below: performing halftone processing for image data by using the first threshold value matrix or the second threshold value matrix selected based on attribute information on the image data, and the first threshold value matrix includes threshold values whose maximum number of bits is N and the second threshold value matrix includes threshold values whose maximum number of bits is M (M<N).

In an example method, a dot pattern of pixels including information to be encoded across an image is mapped to a corresponding subset of the grayscale source pixels corresponding to the image to be printed. A value of a grayscale pixel in the subset of the grayscale source pixels is modified based on based on a predetermined threshold pixel value. The value of the grayscale pixel is decreased in response to detecting that the predetermined threshold pixel value is exceeded. The clipping channel color is used to detect the dot pattern of pixels. The image including the subset of pixels with modified values is printed.

A data-bearing medium is disclosed. The data-bearing medium includes a section of cells having a set of opposite-shifted clusters. The cells include a combination of opposite shifts of the set of opposite-shifted clusters, which represent a single value.