Abstract: Systems and methods for operating a printing system. The methods comprise: identifying a pixel in a bit map (BM) in which ink drop is to be ejected by inoperative inkjet (the pixel having a first drop value (DV)); identifying other pixels in BM that are to be analyzed in a pixel order defined by a displacement map (each other pixel having a second DV); performing a higher preference action analysis of only first ones of the pixels assigned a given priority level of a plurality of different priority levels defined by a priority map to determine whether a higher preference action (TPA) is allowable based on first and second DVs; and performing a lower preference action analysis of only the first ones of the pixels to determine whether a lower preference action is allowable based on first and second DVs, when a determination is made that HPA is not allowable.

Abstract: Methods of identifying and measuring resolution error in a print device are disclosed. The methods include processing a scan of a document on which targets are printed at known reference locations. The system identifies and performs a 1D Hough transform process on each of the targets. In the process, the system measures differences between an identified location for each target and an expected location for each target. The system then uses the difference to measure the document's image resolution and estimate resolution error, if any, in the document.

Abstract: A method for compensating for defective ink jets includes, for an original halftone screen including cells arranged in columns and rows, each cell comprising a threshold value, identifying a first column in the original halftone screen corresponding to a defective inkjet in a marking device. A permuted halftone screen is generated from the original halftone screen with a protocol which includes, for each row in the original halftone screen, providing for swapping a threshold value of a cell in the identified first column with threshold values in cells of neighboring columns, such that the first column assumes the largest threshold value of: the threshold value in the identified first column, a threshold value in a first of the neighboring columns, and a threshold value in a second of the neighboring columns. The permuted screen is stored for halftoning an input image to be printed by the marking device.

Abstract: A method for forming an image by a print device includes: identifying a first pixel in halftone image data, the halftone image data representing an image to be formed, the first pixel corresponding to a malfunctioning inkjet of a plurality of inkjets. The method further includes identifying a neighboring pixel within a region of the image around the first pixel, the neighboring pixel corresponding to a functioning inkjet. The method further includes generating a modified halftone value for the neighboring pixel by: identifying a missing color associated with the malfunctioning inkjet, identifying a replacement color to compensate the missing color (the replacement color being a different color than the missing color), and modifying a halftone value for the neighboring pixel based on the replacement color. The method further includes causing the functioning inkjet to eject an ink drop based on the modified halftone value for the neighboring pixel.

Abstract: A method of inkjet printer operation produces a security pattern in a printed document. In one embodiment, the security feature is printed in the document as a line target with printheads that have been rotated so the rows of inkjets in the printhead are not aligned in the cross-process direction. The line target in the original document has a frequency response to that differs from a copy formed with a device that does not have rotated printheads. In another embodiment, a sneeze pattern is modified by shifting pixels of at least one color separation in the sneeze pattern in a cross-process direction or a process direction. A copy is identified because it does not contain the shifted pixels.

Abstract: A method for operating a three-dimensional (3D) metal object manufacturing apparatus compensates for surface deviations of overhanging features differently than for non-overhanging features. The compensation method used for the overhanging features depends on whether an edge of the overhanging feature being formed in a next layer has curved or sharp corners.

Abstract: A three-dimensional (3D) metal object manufacturing apparatus is operated to compensate for surface deviations of overhanging features differently than for non-overhanging features. The compensation technique used for the overhanging features depends on whether an edge of the overhanging feature being formed in a next layer has curved or sharp corners.

Abstract: Systems for and methods of providing a feed rate for three-dimensional printing a part are presented. The disclosed techniques include: obtaining computer readable toolpath instructions for the part, where the toolpath instructions specify a nominal feed rate for a toolpath segment and spatial toolpath data of the toolpath segment; providing an input including the spatial toolpath data to a trained machine learning system, where the trained machine learning system has been trained using training data including: training spatial toolpath data, training closed loop gain data, and training feed rate data; obtaining a revised feed rate for the toolpath segment different from the nominal feed rate for the toolpath segment, where the revised feed rate is output from the trained machine learning system; and providing revised computer readable toolpath instructions, where the revised machine learning toolpath instructions include the revised feed rate.

Abstract: A method of inkjet printer operation produces a security pattern in a printed document. In one embodiment, the security feature is printed in the document as a line target with printheads that have been rotated so the rows of inkjets in the printhead are not aligned in the cross-process direction. The line target in the original document has a frequency response to that differs from a copy formed with a device that does not have rotated printheads. In another embodiment, a sneeze pattern is modified by shifting pixels of at least one color separation in the sneeze pattern in a cross-process direction or a process direction. A copy is identified because it does not contain the shifted pixels.

Abstract: A slicer in a material drop ejecting three-dimensional (3D) object printer identifies the positions and local densities for a plurality of infill lines within a perimeter to be formed within a layer of an object to be formed by the printer. The local density of each infill line is filtered and a control law is applied to the filtered local density to identify an error in the local density compared to a target density. This process is performed iteratively until the error is within a predetermined tolerance range about the target local density. The error is used to generate machine ready instructions to operate the 3D object printer to achieve the target density for the infill lines.

Abstract: A method of inkjet printer operation produces a sneeze pattern having a uniform sneeze pattern portion and a tapered area portion within the uniform sneeze pattern to operate inkjets in the printer to eject ink drops within an image area of media sheets passing through the printer to maintain the operational status of the inkjets. A dynamic threshold is applied to a portion of an uniform sneeze pattern to produce the tapered area within the uniform sneeze pattern. The dynamic threshold is changed as a function of distance between a pixel in the portion of the uniform sneeze pattern and the closest edge of an image area of the media sheet on which the tapered area of the sneeze pattern is to be printed. A second threshold can also be changed to alter a volume of ink associated with a pixel in the tapered area within the uniform sneeze pattern.

Abstract: A slicer in a material drop ejecting three-dimensional (3D) object printer determines the number of material drops to eject to form a perimeter in an object layer and distributes a quantization error over the layers forming the perimeter. The slicer also identifies the location for the first material drop ejected to form the perimeter using a blue noise generator.

Abstract: An MFD is disclosed. For example, the MFD includes a color printhead to dispense color printing fluid, an enhancement printhead to dispense a three-dimensional (3D) print material, a processor and a non-transitory computer-readable medium storing a plurality of instructions. The instructions when executed by the processor cause the processor to perform operations that include printing a two-dimensional (2D) image on a substrate and printing a 3D object on the 2D image printed on the substrate such that colors of the 2D image provide a desired color for a desired portion of the 3D object.

Abstract: A three-dimensional (3D) metal object manufacturing apparatus is operated to compensate for surface deviations of overhanging features differently than for non-overhanging features. The compensation technique used for the overhanging features depends on whether an edge of the overhanging feature being formed in a next layer has curved or sharp corners.

Abstract: A method of inkjet printer operation indicates a need for printhead purging without requiring analysis of printed images to detect streakiness in the images. The method compares terms of a histogram of a filtered response of an inkjet status vector to a streakiness metric to determine whether the distribution of inoperative inkjets in a printhead enables missing ink techniques to be used to compensate for inoperative inkjets in the printhead.

Abstract: A method of inkjet printer operation produces a sneeze pattern having a uniform sneeze pattern portion and a tapered area portion within the uniform sneeze pattern to operate inkjets in the printer to eject ink drops within an image area of media sheets passing through the printer to maintain the operational status of the inkjets. A dynamic threshold is applied to a portion of an uniform sneeze pattern to produce the tapered area within the uniform sneeze pattern. The dynamic threshold is changed as a function of distance between a pixel in the portion of the uniform sneeze pattern and the closest edge of an image area of the media sheet on which the tapered area of the sneeze pattern is to be printed. A second threshold can also be changed to alter a volume of ink associated with a pixel in the tapered area within the uniform sneeze pattern.

Abstract: A slicer in a material drop ejecting three-dimensional (3D) object printer identifies the positions and local densities for a plurality of infill lines within a perimeter to be formed within a layer of an object to be formed by the printer. The local density of each infill line is filtered and a control law is applied to the filtered local density to identify an error in the local density compared to a target density. This process is performed iteratively until the error is within a predetermined tolerance range about the target local density. The error is used to generate machine ready instructions to operate the 3D object printer to achieve the target density for the infill lines.

Abstract: A slicer in a material drop ejecting three-dimensional (3D) object printer identifies the positions and local densities for a plurality of infill lines within a perimeter to be formed within a layer of an object to be formed by the printer. The local density of each infill line is filtered and a control law is applied to the filtered local density to identify an error in the local density compared to a target density. This process is performed iteratively until the error is within a predetermined tolerance range about the target local density. The error is used to generate machine ready instructions to operate the 3D object printer to achieve the target density for the infill lines.

Abstract: An apparatus is disclosed that automatically generates a set of recommended printer settings 300 for a print job 100 submitted to a printer 10.

Abstract: An MFD is disclosed. For example, the MFD includes a color printhead to dispense color printing fluid, an enhancement printhead to dispense a three-dimensional (3D) print material, a processor and a non-transitory computer-readable medium storing a plurality of instructions. The instructions when executed by the processor cause the processor to perform operations that include printing a two-dimensional (2D) image on a substrate and printing a 3D object on the 2D image printed on the substrate such that colors of the 2D image provide a desired color for a desired portion of the 3D object.