Abstract: A system for estimating distance to regions in a scene during image capture comprising a lens; a split color filter with complementary colors located at a stop associated with the lens and configured to split an image of a scene received from the lens into two complementary images having complementary colors; a color image sensor configured to simultaneously receive the two complementary images; and a data processing system configured to at least estimate distances to regions in the scene based at least upon an analysis of the received complementary images.

Abstract: A method for modifying an input digital image having an (x, y) array of pixels, each pixel having an input code value for one or more color channels, wherein said input code value has a nonlinear relationship to colorant amount, to form an output digital image containing output code values for each pixel subject to a total colorant amount limit.

Abstract: An ink jet printer apparatus and method includes a print head having at least one nozzle. In response to a signal related to media type that is to be recorded upon, gray level image data relating to at least three different drop volumes including no ink drop are recorded at different pixel locations to form dots of different dot size or dot density on the recording medium. In recording image data of the same multitone image data value on different media, drop volumes deposited on one medium by the nozzle are different than drop volumes deposited on another medium by that nozzle. In some embodiments or printing modes image data is also recorded by depositing a variable size dot on a reference raster location and a supplementary dot at an adjacent pixel location on a shifted raster.

Abstract: An ink jet printer apparatus and method includes a print head having at least one nozzle. In response to a signal related to media type that is to be recorded upon, gray level image data relating to at least three different drop volumes including no ink drop are recorded at different pixel locations to form dots of different dot size or dot density on the recording medium. In recording image data of the same multitone image data value on different media, drop volumes deposited on one medium by the nozzle are different than drop volumes deposited on another medium by that nozzle. In some embodiments or printing modes image data is also recorded by depositing a variable size dot on a reference raster location and a supplementary dot at an adjacent pixel location on a shifted raster.

Abstract: A method for modifying an input digital image having an (x, y) array of pixels, each pixel having an input code value for one or more color channels, wherein said input code value has a nonlinear relationship to colorant amount, to form an output digital image containing output code values for each pixel subject to a total colorant amount limit.

Abstract: An ink jet printer apparatus and method of printing wherein image data representing a predetermined number of gray levels of pixels to be printed are accommodated in an inkjet printer for recording on a receiver medium. The printer has the capability of producing fewer numbers of gray levels at respective pixel positions than the data requires. The inkjet printer prints an increased number of the gray levels by applying multitone printing to pixels locations on a reference raster and provides supplementary ink drops to respective adjacent pixel locations on a shifted raster.

Abstract: An ink jet print head includes an array of nozzles, each nozzle being capable of selectively producing when actuated at least two ink drop sizes including a larger ink drop size and a smaller ink drop size. In response to a pixel density signal of maximum density value at a respective pixel location, a nozzle prints a drop of the larger ink drop size at the respective pixel location on a reference raster and the same or a different nozzle prints a drop of a smaller drop size at a pixel location adjacent to the respective pixel location on a shifted raster to provide for full coverage with improved dry time capability of the printed ink drops.

Abstract: A method of multipass inkjet printing of images in response to digital images having code values includes providing an inkjet printer capable of printing at least two ink drops at each printing location during different passes, including a printhead which can select at least two different ink drop sizes, and selecting a number of passes for producing an image and providing a print mask having mask values which, in each pass, sequentially corresponds to predetermined pixels and, in response to the mask values and the code values of such pixels, operates the inkjet printer to select the ink drop size for each pixel in each pass so that the inkjet printer produces an image.

Abstract: A method for modifying an input image suitable for printing on a digital printer having two or more colorants, wherein at least two of the colorants are similar having substantially the same color but different densities, to form an output image with pixels representing modified colorant amounts subject to a total colorant amount limit.

Abstract: A method for modifying an input image having an (x,y) array of input pixels, each pixel having an input colorant amount for one or more color channels to form an output image with output colorant amounts, said output image being suitable for printing on a digital printing device having two or more printing levels, including determining an average total pixel colorant amount in a neighborhood of an input pixel in the input image; determining a colorant reduction amount for each color channel of the input pixel responsive to the input colorant amount, the average total pixel colorant amount, and a threshold colorant amount; determining an output colorant amount for each color channel of the input pixel responsive to the colorant reduction amount, the input colorant amount, and a spatially periodic dither signal, so that the average output colorant amount in a neighborhood of each pixel in the output image is constrained to be less than the threshold colorant amount; and repeating steps a) through c) for each pi

Abstract: Digital ink jet printing apparatus and method. The apparatus receives an input image file having a plurality of pixels, each pixel described by at least one pixel value respectively associated with an optical density. The apparatus comprises a printhead and at least one nozzle integrally attached to the printhead, the nozzle being capable of ejecting an ink droplet therefrom to define an associated one of the optical densities. A waveform generator is connected to the nozzle for generating an electronic waveform to be supplied to the nozzle. In this manner, the nozzle ejects the ink droplet in response to the waveform supplied thereto. The waveform is defined by a plurality of pulses. A look-up table stores a plurality of waveform serial numbers assigned to respective waveforms, each waveform being defined by at least one predetermined parameter, such as number of pulses, pulse amplitude, pulse width and/or time delay between pulses.

Abstract: A method for reproducing digital images having at least one color channel containing pixels using a digital printer having a set of colorants is disclosed. Two or more of the colorants of the set have substantially the same color but different densities. Printer code values for a particular color channel are used to control colorant amounts for the two or more colorants.

Abstract: A method for halftoning a multi-channel digital color image having an x,y array of color pixel values, includes the steps of: providing a matrix of dither values for each color channel of the digital color image wherein two or more of the matrices of dither values are designed jointly to minimize a visual cost function; for each color channel modularly addressing the matrix of dither values with the location of a pixel in the digital color image to obtain an addressed dither value; comparing the addressed dither value for each color channel with the pixel value for the corresponding color channel to determine an output halftone image value for each color channel; and repeating steps b and c for each pixel in the digital image.

Abstract: A method for processing a digitized continuous tone image so that such processed image is adapted to be applied to an image rendering device which prints dots from a set of two or more possible dot-areas and from a set of colorants having different colorant concentrations is disclosed. The method includes selecting a set of N dot-area and colorant concentration combinations, each of said combinations producing a different integrated optical density value and multilevel halftone processing the digitized continuous tone image to produce an output image having a set of output levels wherein one member of the set of N dot-area and colorant concentration combinations is associated with each of the possible output levels.

Abstract: A method for halftoning a digital image having an x,y array of pixels each having an associated input pixel value, includes the steps of providing a memory containing a dither bitmap for each input pixel value of the digital image where the dither bitmaps are partially correlated; selecting a dither bitmap corresponding to the input pixel value for a pixel in said digital image; modularly addressing the selected dither bitmap with the location of said pixel to obtain an output halftone image value; and repeating steps for each pixel in the digital image.

Abstract: A method for halftoning a multi-channel digital color image having an x,y array of color pixel values, includes the steps of: providing a matrix of dither values for each color channel of the digital color image wherein two or more of the matrices of dither values are designed jointly to minimize a visual cost function; for each color channel modularly addressing the matrix of dither values with the location of a pixel in the digital color image to obtain an addressed dither value; comparing the addressed dither value for each color channel with the pixel value for the corresponding color channel to determine an output halftone image value for each color channel; and repeating steps b and c for each pixel in the digital image.

Abstract: An error diffusion method suitable for producing an output image from an input image having a set of digitized continuous-tone pixels is disclosed. The method includes the steps of computing an image activity signal; computing a set of activity weights from the image activity signal; computing a filtered input value for a digitized continuous-tone input pixel responsive to the activity weights and computing a filtered output value responsive to the activity weights for each of the possible output levels. The method further includes selecting the output level in response to the filtered input value and the filtered output value for each of the possible output levels according to an error criterion; determining an error signal between the filtered input value and the filtered output value for the selected output level; and weighting the error signal and adjusting the filtered input values for nearby pixels which have not yet been processed.

Abstract: A method for forming a multi-level halftone image from an input digital image having a plurality of pixels so that visibility of halftone patterns is minimized; comprises the steps of transforming input pixel values which represent the tone level of each pixel into modified pixel values which are approximately linear with perceived lightness; applying a multi-level halftoning process to the modified pixel values to produce halftone pixel values having a reduced number of tone levels which are uniformly distributed with respect to the modified pixel values; and transforming the halftone pixel values into output pixel values for permitting an output device to display the digital image so that visibility of halftone patterns is minimized.

Abstract: An improved method for removing blocking artifacts in regions of slowly varying intensity in an electronic image decoded from a transform coded representation of an image, includes the steps of: receiving signals indicative of DC and AC coefficient values of transformed blocks of image data; modifying the DC value in each of the blocks based on the level of activity within the block and the DC values in neighboring blocks; performing AC prediction in each block using the modified DC values; replacing the AC values in each block with the AC predicted values based on the level of activity within the block and the modified DC values in neighboring blocks; and reconstructing the image using the modified DC and AC coefficient values.

Abstract: A halftone processing method is disclosed in which, after receiving three or more monochrome digital images which collectively represent a color image having three colors, processing takes place. Processing is by a separate stage for each of the monochrome digital images to provide halftone output images, wherein at least one of the stages uses a different processor algorithm from the other halftone processing stages so as to increase processing speed.