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.

A method for selecting a colorant amount for printing is described in which a maximum optical density of an image is identified. The maximum optical density is compared to with a threshold optical density, and when the threshold is exceeded, dot cluster sizes from a first lookup table are selected, otherwise, dot cluster sizes from a second lookup table are selected. A colorant thickness corresponding to the selected dot cluster sizes is selected for printing the image.

Systems and methods to generate a multi-mode image containing different modes such as color, grayscale, and black and white to minimize digital file size while retaining the desired modes for selected portions of the image.

A special-purpose image processor can convert an electronic file into a bitmap by generating printing halftone dots within the bitmap based on locations of colors within the electronic file, and generating non-printing dots within the bitmap. A printing apparatus can print the bitmap, by not print marking materials where the non-printing dots are positioned within the bitmap. The special-purpose image processor can generate the non-printing dots within the bitmap by increasing the size of the printing halftone dots until they contact one another, or generating printing lines that connect the printing halftone dots to each other within the bitmap. Also, the special-purpose image processor can generate, as each printing halftone dot, a higher frequency pattern of printing dots, where the non-printing dots are generated to have a lower frequency pattern relative to that higher frequency.

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).

Methods and systems for sequentially quantizing probability density functions for inkjet printing. In an example embodiment, an operation can be implemented to quantize probability density functions associated with larger drops among a plurality of drops provided by an inkjet printer. Non-quantized probability functions associated with remaining ink drops are then modified utilizing an error incurred at each quantization during quantization of the probability density functions associated with the larger drops. Quantizing the probability density functions and modifying the non-quantized probability functions continue until all drop size probability functions associated with the plurality of drops are quantized.

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.

An image formation apparatus for forming an image and test patterns. The image formation apparatus includes a storage unit that stores dither matrix data used to form the image and the test patterns; and an image formation unit that forms the test patterns based on the dither matrix data. A number of tones of the test patterns to be formed by the image formation unit is changed and the number of tones is determined based on a size of the dither matrix data and a number of bits per pixel within the dither matrix data.

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).