An image processing apparatus extracts, from color image data, an object having a first density and an object having a second density being higher than the first density, and determines whether or not sizes of the objects each having the first density and the second density are greater than a predetermined size. When converting the color image data into monochromatic image data, an object having the first density and a size less than or equal to the predetermined size is converted to have a higher density than an object having the first density and a size greater than the predetermined size, and an object having the second density and a size less than or equal to the predetermined size is converted to have the same density as an object having the second density and a size greater than the predetermined size.

A target area of image data of a scanned document is set, in which the target area has a predetermined size and a target pixel, characteristic amounts indicating the brightness at two pixels among the plurality of pixels included in the set target area are obtained, a determination is made on whether or not the difference between the obtained characteristic amounts indicating the brightness is higher than a threshold, a brightness correction amount is decided based on a characteristic amount indicating the brightness of the target pixel and the result of the determination, and the brightness characteristic amount indicating the brightness of the target pixel is corrected based on the decided correction amount.

An image processing apparatus that is capable of converting an original color image into a monochrome image to which color scheme intention of the original color image is reflected appropriately. An extraction unit extracts colors used for characters and figures in color data. A first determination unit determines one of the colors as a base color. A second determination unit determines another of the colors as an accent color. An application unit converts the color data into monochrome data by applying a predetermined gray to the base color determined and applying a gray that is distinguishable from the predetermined gray and has a density higher than the predetermined gray to the accent color.

An image processing apparatus converts multi-valued data into multi-valued quantized data having fewer levels than the multi-valued data. The apparatus includes an acquisition unit that acquires threshold values, a provisional quantization unit that sets a provisional quantized value with respect to the multi-valued data, and a quantization unit that decides a quantized value with respect to the multi-valued data based on a result of comparing comparative multi-valued data for the multi-valued data to the threshold value. The quantization unit decides the quantized value so that in a case where the multi-valued data is the same intermediate value, pixels having the value larger than provisional quantized value increase, pixels having the provisional quantized value do not change in number, and pixels having the value smaller than the provisional quantized value decrease in a designated pixel area as the value of the multi-valued data rises.

An example embodiment may involve causing a page of a document to be printed on a printing device, wherein the printing device is in an AM halftoning mode and prints the page using an AM halftone; displaying, on the display unit, a graphical user interface, wherein the graphical user interface includes a selectable option to switch the printing device from the AM halftoning mode to an FM halftoning mode; receiving an indication that the selectable option has been selected; possibly in response to receiving the indication that the selectable option has been selected, causing the printing device to switch from the AM halftoning mode to the FM halftoning mode; and causing the page of the document to be printed again on the printing device, wherein the printing device is in the FM halftoning mode and prints the page using an FM halftone.

A printing apparatus has a plurality of nozzles capable of discharging dark ink and light ink that are of the same type color; the plurality of nozzles includes preceding nozzles that discharge the ink onto the printing medium before the ink discharge of the other nozzles, and succeeding nozzles that discharge the ink onto the printing medium after the ink discharge of the preceding nozzles, and if the amount of the dark ink discharged on the printing target region is larger than a predetermined amount, the printing apparatus discharges a smaller amount of the light ink than the amount of the discharged dark ink onto the printing target region from the plurality of nozzles so that the amount of the light ink discharged from the succeeding nozzles is larger than the amount of the light ink discharged from the preceding nozzles.

White-balance is improved when printing on colored media, while minimizing the time and use of costly materials required by present approaches. In an embodiment, the typical solid white fill or background layer is altered by including in the white layer one or more of the other colors already available in the printer to shade this layer. Thus, a small amount of cyan, for example, helps balance a pink-ish (red) media; yellow is used for blue media; and magenta is used for green media; as well as combinations thereof. A combination of transparent process inks and opaque white helps to maintain brightness (luminosity).

An image processing method comprising: converting an RGB input signal to a CMYK signal; converting the RGB input signal to a common color signal including lightness; generating a first Gray signal including a Gray value substituted for CMY values forming gray in the CMYK signal; generating a second Gray signal including a Gray value corresponding to a K value greater than a threshold in the CMYK signal; generating a Gray output signal in a CMYKGray output signal indicating color material amounts of cyan (C), magenta (M), yellow (Y), black (K), and gray (Gray) for printing by multiplying the generated first Gray signal and the generated second Gray signal respectively by coefficients corresponding to the lightness in the common color signal and then synthesizing the first Gray signal and the second Gray signal.

In an example, a halftone screen is generated. A plurality of amplitude-modulated dot clusters is arranged in correspondence with a grid. Each of the amplitude-modulated dot clusters comprises a plurality of frequency-modulated dots.

In an error diffusion process, a control device determines a dot value of a target pixel by using a gradation value of the target pixel, and an error value. The control device determines distribution error value by comparing a gradation dependent value with a first evaluated density value indicating a density of a first dot. The control device determines the distribution error value by using the first evaluated density value when the dot value of the target pixel indicates formation of the first dot and when the gradation dependent value is smaller than or equal to the first evaluated density value. The control device determines the distribution error value by using a modified evaluated density value greater than the first evaluated density value when the dot value indicates formation of the first dot and when the gradation dependent value is greater than the first evaluated density value.