Abstract: Image plane registration errors are corrected for a multi-channel printing system that prints on a continuous web of media. Nominal in-track line spacing are defined for each image plane, and are used to print lines of image data for each image plane. An in-track registration error is measured for a misregistered image plane in the printed image, and is used to determine an adjusted in-track line spacing that will bring the misregistered image plane back into registration in the in-track direction over a predefined correction time interval. Additional image data is then printed using the adjusted in-track line spacing during the correction time interval, after which image data is printed using a new in-track line spacing that is different from the adjusted in-track line spacing.

Abstract: Image plane registration errors are corrected for a multi-channel printing system that prints on a continuous web of media. Nominal in-track line spacing are defined for each image plane, and are used to print lines of image data for each image plane. An in-track registration error is measured for a misregistered image plane in the printed image, and is used to determine an adjusted in-track line spacing that will bring the misregistered image plane back into registration in the in-track direction over a predefined correction time interval. Additional image data is then printed using the adjusted in-track line spacing during the correction time interval, after which image data is printed using a new in-track line spacing that is different from the adjusted in-track line spacing.

Abstract: A method for aligning multi-channel digital image data for a digital printer having an array of printheads for each of a plurality of channels is described. A test pattern including test pattern indicia printed using individual printheads is scanned and analyzed to detect locations of the printed test pattern indicia. For each array position, one of the printheads is designated to be a reference printhead, and one or more of the other printheads are designated to be non-reference printheads. Spatial adjustment parameters are determined for each of the non-reference printheads responsive to the detected test pattern indicia locations. Digital image data to be printed with the non-reference printheads is modified in accordance with the determined spatial adjustment parameters.

Abstract: A method for aligning multi-channel digital image data for a digital printer having a plurality of printheads is described. A test pattern including test pattern indicia printed using individual printheads is scanned and analyzed to detect locations of the printed test pattern indicia. One of the printheads is designated to be a reference printhead, and one or more of the other printheads are designated to be non-reference printheads. Spatial adjustment parameters are determined for each of the non-reference printheads responsive to the detected test pattern indicia locations. Digital image data for the non-reference printheads is modified by designating an input pixel neighborhood within which an image pixel should be inserted or deleted, comparing the image pixels in the input pixel neighborhood to a plurality of predefined pixel patterns to identify a matching pixel pattern; and determining a modified pixel neighborhood responsive to the matching pixel pattern.

Abstract: A method for aligning multi-channel digital image data for a digital printer having a plurality at least one printhead is described. One or more spatial adjustment parameters are determined for each of the printheads. The spatial adjustment parameters can be determined by comparing locations of test pattern indicia in a printed test pattern to predefined reference indicia locations. Digital image data for the non-reference printheads is modified by designating an input pixel neighborhood within which an image pixel should be inserted or deleted, comparing the image pixels in the input pixel neighborhood to a plurality of predefined pixel patterns to identify a matching pixel pattern; and determining a modified pixel neighborhood responsive to the matching pixel pattern.

Abstract: A method for aligning multi-channel digital image data for a digital printer having a plurality at least one printhead is described. One or more spatial adjustment parameters are determined for each of the printheads. The spatial adjustment parameters can be determined by comparing locations of test pattern indicia in a printed test pattern to predefined reference indicia locations. Digital image data for the non-reference printheads is modified by designating an input pixel neighborhood within which an image pixel should be inserted or deleted, comparing the image pixels in the input pixel neighborhood to a plurality of predefined pixel patterns to identify a matching pixel pattern; and determining a modified pixel neighborhood responsive to the matching pixel pattern.

Abstract: A method for aligning multi-channel digital image data for a digital printer having an array of printheads for each of a plurality of channels is described. A test pattern including test pattern indicia printed using individual printheads is scanned and analyzed to detect locations of the printed test pattern indicia. For each array position, one of the printheads is designated to be a reference printhead, and one or more of the other printheads are designated to be non-reference printheads. Spatial adjustment parameters are determined for each of the non-reference printheads responsive to the detected test pattern indicia locations. Digital image data to be printed with the non-reference printheads is modified in accordance with the determined spatial adjustment parameters.

Abstract: A method for aligning multi-channel digital image data for a digital printer having a plurality of printheads is described. A test pattern including test pattern indicia printed using individual printheads is scanned and analyzed to detect locations of the printed test pattern indicia. One of the printheads is designated to be a reference printhead, and one or more of the other printheads are designated to be non-reference printheads. Spatial adjustment parameters are determined for each of the non-reference printheads responsive to the detected test pattern indicia locations. Digital image data for the non-reference printheads is modified by designating an input pixel neighborhood within which an image pixel should be inserted or deleted, comparing the image pixels in the input pixel neighborhood to a plurality of predefined pixel patterns to identify a matching pixel pattern; and determining a modified pixel neighborhood responsive to the matching pixel pattern.

Abstract: Apparatus for processing a signal of a predetermined intermediate frequency (IF) to generate in-phase (I) and quadrature (Q) components thereof comprises: an analog-to digital converter circuit for sampling and digitizing the IF signal to generate digitized data samples thereof at a sampling rate that produces consecutive digitized data samples that are separated in phase by a substantially fixed phase angle 2&pgr;/n, where n is an integer greater than zero; first digital circuitry coupled to the analog-to digital converter circuit for demodulating the digitized data samples by multiplying every n consecutive digitized data samples with n respectively corresponding digital reference samples; and second digital circuitry coupled to the first digital circuitry for combining selected ones of the demodulated samples based on the substantially fixed phase angle to generate digital data samples of the I and Q components of the IF signal.