Multiple first gradation values corresponding respectively to the multiple inks are quantized to generate multiple first quantized values indicating printing or non-printing of dots with the respective inks. In this case, multiple second gradation values corresponding respectively to multiple multinary colors expressible by combinations of overlapping of the multiple inks are generated based on the first gradation values. Next, the multiple second gradation values are quantized to generate multiple second quantized values indicating printing or non-printing of dots of the respective multinary colors. Then, the first quantized values corresponding to the inks to be overlapped one on top of another to express the multinary colors are generated based on the second quantized values corresponding respectively to the multiple multinary colors.

A printing system is disclosed. The printing system includes at least one physical memory device to store calibration logic and one or more processors coupled with the at least one physical memory device to execute the calibration logic to generate a uniformity compensated halftone design for each of a plurality of pel forming elements, generate a missing neighbor corrected halftone design for each of the pel forming elements, generate a missing neighbor threshold lowering function for each of the pel forming elements based on the uniformity compensated halftone designs and the missing neighbor corrected halftone design and compute an average of the missing neighbor threshold lowering functions to generate an average missing neighbor threshold lowering function.

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.

A printing system is disclosed. The printing system includes at least one physical memory device to store calibration logic and one or more processors coupled with the at least one physical memory device to execute the calibration logic to generate a uniformity compensated halftone design for each of a plurality of pel forming elements, generate a missing neighbor corrected halftone design for each of the pel forming elements, generate a missing neighbor threshold lowering function for each of the pel forming elements based on the uniformity compensated halftone designs and the missing neighbor corrected halftone design and compute an average of the missing neighbor threshold lowering functions to generate an average missing neighbor threshold lowering function.

An image processing apparatus converts a multivalued image to a binary image, determines a character region and a non-character region in the binary image, extracts areas in units of a character from the character region, determines whether each of the areas is a character region or a non-character region, and extracts, for each of the areas determined to be the character region, a first representative color from the multivalued image included in the area, and generates a binary image corresponding to the first representative color. The apparatus decides a second representative color closest to a color of a target pixel by comparing the first representative color with the color of the target pixel, and changes the binary image of the area corresponding to the first representative color to a binary image of the decided second representative color.

A printing system is provided and includes an image processing portion that generates a generated image by image processing, and a printing portion that performs printing on a medium based on the generated image. The image processing portion generates the generated image by performing a quantization processing that performs quantization by comparing the pixel value of each pixel in the input image with a threshold, and in the quantization processing, calculates a dot influence value indicating to what extent a position corresponding to a selected pixel is covered by the ink dots formed at the position set on the medium in correspondence with the peripheral pixels of the selected pixel, performs adjustment of reflecting the dot influence value on at least one of the pixel value of the selected pixel or the threshold, and compares the pixel value and the threshold based on a value after adjustment.

The image processing apparatus obtains a degree of variation in signal values of a plurality of pixels included in a region of a predetermined size that includes a pixel of interest of image data obtained by reading a document on which a halftone-processed image has been printed, obtains a feature amount indicating a brightness of the region. The apparatus updates a difference between the obtained feature amount and an index value corresponding to the obtained degree of variation in accordance with whether or not the difference is larger than a predetermined threshold, with respect to a plurality of index values respectively corresponding to a plurality of mutually different degrees of variation, decides a correction value of the pixel of interest using the updated difference and the index value, and corrects a value of the pixel of interest using the decided correction value.

An object of the present invention is to implement a bit pattern capable of specifying a plurality of colors while storing information on a shape. The present invention is an image processing apparatus that converts image data in a bitmap format into data including a bit pattern, the apparatus including: a creation unit configured to create, based on pixel values of pixels within an image area of a predetermined size within the image data, the bit pattern storing shape information on the image area, which specifies to which of a plurality of kinds of pixel each pixel within the image area corresponds, and color information on the image area, which specifies a number of colors in accordance with a kind of pixel specified by the shape information, and the number in accordance with a kind of pixel specified by the shape information is smaller than a total number of pixels within the image area.

A control apparatus for generating a control signal for controlling a printer on the basis of an input signal includes: an arithmetic unit configured to generate an error diffusion processing signal by subtracting, from the input signal, an error diffusion output signal output from a diffusion matrix that determines a distribution of a print density error; a multiplier unit configured to generate an intermediate signal by multiplying the error diffusion processing signal by a correction gain for controlling a correction amount of the print density error; and a quantizer unit configured to generate the control signal by quantizing the intermediate signal.

A printing system is provided and includes an image processing portion that generates a generated image by image processing, and a printing portion that performs printing on a medium based on the generated image. The image processing portion generates the generated image by performing a quantization processing that performs quantization by comparing the pixel value of each pixel in the input image with a threshold, and in the quantization processing, calculates a dot influence value indicating to what extent a position corresponding to a selected pixel is covered by the ink dots formed at the position set on the medium in correspondence with the peripheral pixels of the selected pixel, performs adjustment of reflecting the dot influence value on at least one of the pixel value of the selected pixel or the threshold, and compares the pixel value and the threshold based on a value after adjustment.