There are provided image processing device and method, a printing system, a halftone process determination method, and a program capable of determining a processing rule of an appropriate halftone process appropriate for characteristics of a printing system. An image processing device (20) according to the present invention includes characteristic parameter acquisition means (52) for acquiring characteristic parameters related to characteristics of a printing system, and halftone process generation means (58) for generating halftone processing rules that define the processing contents of two or more kinds of halftone processes of which balances of priority for a plurality of requirements required in the halftone process are different based on the characteristic parameters acquired by the characteristic parameter acquisition means (52).

A correction method for an image forming apparatus including a light source including light emitting points, a photosensitive member configured to rotate in a first direction, and a deflecting unit configured to deflect light beams emitted from the light source in a second direction orthogonal to the first direction, the correction method includes: a first correction step of correcting sparseness and denseness of density in the first direction by moving a predetermined pixel in the first direction, and causing a pixel value of the predetermined pixel to be output or not to be output in accordance with movement of the predetermined pixel; and a second correction step of correcting the pixel value of the predetermined pixel by moving the pixel value of the predetermined pixel in the second direction so that a pixel value is caused to be output or not to be output with a plurality of continuous pixels.

An image processing apparatus for printing an image on a print medium by using a printing unit that ejects a first ink in accordance with first quantized data and ejects a second ink in accordance with second quantized data, the image printing apparatus has a first quantization configured to quantize multi-valued data corresponding to the first ink to generate the first quantized data, the multi-valued data indicating intermediate density; and a second quantization unit configured to quantize multi-valued data corresponding to the second ink to generate the second quantized data, the multi-valued data indicating intermediate density. Surface tension of the first ink is larger than surface tension of the second ink, and a first dot pattern printed on the print medium in accordance with the first quantized data has higher dispersibility than a second dot pattern printed on the print medium in accordance with the second quantized data.

An image forming apparatus includes: a photosensitive member rotating in a first direction; a light scanning device, when the photosensitive member rotates at a slower speed, irradiate the photosensitive member with light beam through use of part of scanning lines corresponding to the slower speed; a storage unit in which information on positional deviation of the scanning lines in the first direction is stored; and a correction portion calculating a correction value for correcting positional deviation amounts of a predetermined scanning line and a scanning line group, which is included within a predetermined range in an advance direction and a return direction in the first direction from the predetermined scanning line, with extracting information corresponding to the part of the scanning lines from the stored information when the photosensitive member rotates at the slower speed, and correcting positional deviation of the predetermined scanning line based on the calculated correction value.

The present invention provides an image contrast enhancement method, which respectively calculates the absolute values of the differences of the gray scales between the pixels of two adjacent row of the same column and between the pixels of two adjacent column of the same row, and respectively calculates the first gray scale value weight and the second gray scale value weight according to the absolute values. Then, the cumulative calculation and the normalization process are performed according to the first, the second gray scale value weights. Ultimately, the enhancement gray scale table is obtained for redistributing the gray scale values of the respective pixels, which can raise the contrast of the image, reduce the distortion of the image and optimize the display result.

A filter processing unit performs a bandpass filter process for a difference between an output pixel value and an input pixel value of an adjacent pixel to a target pixel. An error diffusion unit performs an error diffusion process of a quantization error for output of the filter processing unit. A quantizer performs quantization for a value obtained by the error diffusion process and thereby determines the output pixel value of the target pixel. The bandpass filter process is performed with characteristics different from each other (a) in respective ones of a primary scanning direction and a secondary scanning direction and (b) for respective ones of the component colors of the image. Furthermore, a filter coefficient of the bandpass filter process independently for each component color of an image is corrected for banding reduction with a correction coefficient corresponding to an angle from the primary scanning direction.

In various embodiments, an image processing method using self-adaptive error diffusion algorithm, a related apparatus and device are provided. In some embodiments, the method comprises: determining a neighboring region in an original image for error diffusion process, the neighboring region including a center point and its adjacent points; based on pixel values of the center point and the adjacent points, calculating an error diffusion process weight value for each adjacent point corresponding to an error diffusion process from the center point towards each adjacent point; after binarizing the pixel value of the center point, calculating an error value according to the binarized pixel value of the center point; adding a product of the error diffusion process weight value for each adjacent point and the error value to the pixel value of each adjacent point respectively to obtain an error-diffusion-processed pixel value for each adjacent point in the neighboring region.

Techniques related to rendering scanned images are discussed. Such techniques may include selectively processing segments of a scanned input image based on a neutral edge tag signal such that segments are color suppressed and edge enhanced when the neutral edge tag signal is asserted and error diffusion processed when the neutral edge tag signal is not asserted.

The present invention provides an image contrast enhancement method, which respectively calculates the absolute values of the differences of the gray scales between the pixels of two adjacent row of the same column and between the pixels of two adjacent column of the same row, and respectively calculates the first gray scale value weight and the second gray scale value weight according to the absolute values. Then, the cumulative calculation and the normalization process are performed according to the first, the second gray scale value weights. Ultimately, the enhancement gray scale table is obtained for redistributing the gray scale values of the respective pixels, which can raise the contrast of the image, reduce the distortion of the image and optimize the display result.

A non-transitory computer-readable storage medium storing a program for causing a computer to execute a control method for making it possible to extend a function of a general-purpose program which can be commonly used for printing apparatuses of a plurality of makers when printing is performed. An extension program causes the printing apparatus to execute halftone processing for generating image data which is provided for a printed matter to be printed based on print data generated by the general-purpose program and expresses halftone on the printed matter.