A method for modifying color density values in a dot-based printing system uses a control unit. The control unit implements the modification of the color density values after a raster image has been created and modifies the number and/or size of print dots to be applied to a printing substrate in order to attain pre-defined color density target values.

An information processing apparatus and an image processing method are provided. The image processing apparatus detects character data from image data, executes edge enhancement processing, using a first filter, on an edge portion of a region, out of the detected character data, that includes a region whose frequency of points or lines is greater than a predetermined frequency, and executes edge enhancement processing, using a second filter, on an edge portion of a region, out of the detected character data, that does not include a region of a spatial frequency higher than the predetermined frequency. The first filter has, in comparison to the second filter, a larger degree for edge enhancement with respect to a region having a frequency higher than the predetermined frequency.

A recording system for recording a recording image based on image data by repeating a pass operation in which a nozzle column discharges ink while reciprocating relatively to a recording medium in a main scanning direction to form dots on the recording medium, and a conveying operation of relatively moving the nozzle column and the recording medium in a sub-scanning direction crossing the main scanning direction, the recording system including an assigning section for obtaining a plurality of halftone data which is generated with respect to the same area of the image data based on the image data, and which corresponds to the ink of a predetermined color, and then assigning each of the halftone data obtained to the pass operations in the same direction in reciprocation in the main scanning direction in a predetermined recording area.

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.

A technique capable of keeping image quality and speeding up a halftone process is provided. An image processing device performs the halftone process on image data in which a pixel has a pixel value conforming to a bit count N. Bits conforming to the bit count N include higher H bits (where H is an integer satisfying an inequality of 1H<N) and lower L bits following the higher H bits (where L is an integer satisfying an inequality of 1LNH). The image processing device includes a first halftone processing unit configured to generate dot data indicative of a formation state of a dot, with respect to a first pixel allowing a determination of a formation state of a dot, based on the higher H bits in the pixel value and higher H bits in a dither mask.

An image processing apparatus includes at least one memory storing instructions and at least one processor executing the instructions to provide an input unit configured to input image data representing a color of an image, and information identifying high gloss and low gloss areas in the image, a first determination unit configured to determine, based on the image data, a recording amount of a printing material for forming the image on a recording medium, and a second determination unit configured to determine a dot arrangement of the printing material by halftone processing for the recording amount according to the information.

A halftone raster image, suitable for rendering a continuous-tone image, which comprises a plurality of regularly tiled spiral dots. Said spiral dots comprise (i) image pixels arranged as a first arc (200) or as a plurality of arcs which together represent a first spiral (100), and (ii) non-image pixels arranged as a second arc (201) or as a plurality of arcs which together represent a second spiral (101), wherein neighbour halftone dots from said plurality of regularly tiled halftone dots represent a double spiral or triple spiral.

In an example, a method includes obtaining, by at least one processor, a first halftone screen tile having a first halftone pattern. In some examples, the method further comprises obtaining a second halftone screen tile having a second halftone pattern. The method may include determining a halftone screen having a predetermined spatial arrangement of the first and second halftone screen tiles wherein the relative placement of the first and second halftone screen tiles in the predetermined spatial arrangement provides a signature for the halftone screen which when applied to image data provides a printed output in which the signature is discernible.

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.

There are provided an image processing apparatus and a control method for controlling the image processing apparatus. The control method includes extracting a high-luminance region including a high-luminance pixel having a higher luminance than a predetermined luminance included in received image data, expanding the high-luminance region by setting pixel values of pixels configuring a surrounding region of the high-luminance region determined based on an area of the high-luminance region to the same pixel value as the high-luminance pixel, and outputting image data having the expanded high-luminance region.