53 results about "Banding Artifact" patented technology

A method for reducing banding artifacts for bi-directional multi-pass printing on an inkjet printer utilizing a printhead with a plurality of ink nozzles includes defining different print masks to be used for leftward and rightward printing passes such that both the order of ink laydown and the timing between ink laydown on different passes are each substantially constant for a given horizontal position within the image, independent of the vertical position within the image; and printing an input image on the inkjet printer with the defined print masks using a bi-directional multi-pass print mode.

A method and system for identifying and determining banding artifacts in digital video content composed of a sequence of moving video pictures includes creating a mask image corresponding to a picture from said sequence of moving video pictures based on global gradient changes to detect potential areas containing banding artifacts. The values of the mask image are scaled thereby making banding artifact detection possible using gradient operators. The banding artifacts are then identified/detected based on the local gradients.

A method and apparatus for detecting banding artifacts in digital images and video contents. The method operates to (i) find the locations of the banding artifacts, (ii) determine the strength of the banding artifact per block, and (iii) determine overall banding artifact strength per picture. The banding artifact detection and strength assignment is done by first finding areas that are prone to banding artifact and then considering the local characteristics of the area to reduce the false detection. The banding artifact strength of a picture is determined by considering the size and the strength of the artifact areas in this picture as well as the artifact strength in the neighboring pictures.

A method and apparatus are disclosed for identifying and removing banding artifacts (i.e., false contours) resulting from insufficient bit depth caused by digital image quantization, conversion, and/or compression. This method includes: explicitly identifying texture block and flat block; de-termination of filter window sizes with the consideration of handling transitions between texture block and flat block; de-banding filtering with edge protection; and noise shaping according to de-banding filter result.

Methods and systems for generating computed tomographic (CT) images from image data acquired during different biological cycles are provided. A computer is programmed to receive a plurality of scan data acquired during a gated acquisition window of each of a plurality of biological cycles, blend the scan data acquired during a first of the plurality of biological cycles with the scan data acquired during a second of the plurality of biological cycles, and construct a final image from the blended data.

Real-time imaging of a moving object such as the heart uses fast imaging with steady precession (FISP) traversing spirals in k-space. After flipping nuclear spins in the object within a slice to be imaged, signals are read out from the nuclear spins while applying read-out magnetic field gradients whereby read-out signals traverse spirals in k-space. Thereafter, the zero moment and first moment of the read-out gradients are driven to zero quickly so that fast imaging with steady state precession is realized without banding artifacts. Motion compensated rewinders are applied after the read-out magnetic field gradients which can be integral with the read-out gradients or comprise separate compensation lobes.

A method of creating a lenticular imaging article. The method comprises printing an interlaced composite image according to a reference grid of a printer, providing a lenticular lens sheet having a plurality of parallel lenticular lines between a plurality of lenslets, selecting an acute angle for an intersection between the first and second axes according to a function of a resolution of the interlaced composite image and a pitch of the lenticular lens sheet, and positioning the lenticular lens sheet so that the intersection forms the acute angle.

A method for reducing banding artifacts in a printed image, including irregularly advancing a media that will be printed upon while employing an entire single mask for marking elements of a printhead; and calculating a difference between an irregular advance amount of the media versus a nominal advance amount of the media. Finally, the single mask is nonuniformly circulated by the difference calculated in order to compensate for the media being irregularly advanced.

A CT system includes a gantry having a rotatable base and having an opening for receiving an object to be scanned, an x-ray source, a CT detector, and a computer programmed to detect a mis-registration at a slab boundary between a first slab and a second slab of a reconstructed image, quantify an amount of mis-registration at the slab boundary, and adjust the reconstructed image at the slab boundary based on the quantification.

Preferably, test-patterns print on separate, multiple print-medium cards, each including a ramp with colors graded along a certain direction—and, superimposed on the ramp, a candidate add-on colorant. Ramps preferably are printed in so-called “customer colors”, common in snapshots and particularly snapshot regions that include sky. Positions or amounts of the candidate add-on colorant canvass a likely range of values that optimize camouflaging or suppression of a banding artifact (due to seams in the pagewide array) that is extended along the same certain direction. For each seam and each “customer color” used, an operator holds up several cards for comparison, selecting the best one to three. Operators thus can evaluate candidate colorant patterns in context of many different tones of the sky and other customer colors. Preferably banding suppression is integrated with linearization: at each seam a series of linearization tables is smoothly interpolated between measurement-based tables for adjacent inkjet dice.

A method and apparatus for reducing artifacts in Computed Tomography (CT) image reconstruction. The method includes: acquiring an original reconstructed image; conducting total variation processing for the original reconstructed image, to generate a total variation reconstructed image; conducting initial metal artifact reduction processing for the original reconstructed image, to generate an initial metal artifact reduction reconstructed image; generating a weighted image based on the total variation reconstructed image and the initial metal artifact reduction reconstructed image, wherein the weighted image reflects that the original reconstructed image contains white-band artifacts; and combining a portion of the original reconstructed image and a portion of the initial metal artifact reduction reconstructed image through the weighted image to generate a final image, wherein the final image does not contain white-band artifact.

Banding artifacts in steady state free precession (SSFP) magnetic resonance imaging (MRI) are reduced by acquiring and combining multiple SSFP images in an augmented matrix where an acquisition vector in k-space is equal to a Fourier matrix of the trajectory on a known distortion operator for each trajectory in k-space.

A computer readable medium contains a program for causing a printer to execute a multipass printing method characterized in that, on any given pass, the number of selected print locations onto which printing ink is deposited by each of N nozzles varies from nozzle to nozzle. The variation is governed in accordance with a weighted smoothing spline function, particularly a polynomial B-spline function of the order “j”, where j is a value equal to one less than the number of passes.

A method of, and apparatus for, reducing the visibility of banding artifacts on a printed medium comprising producing synthetic artifacts on the printed medium, overlapping scan lines at swath boundaries and controlling exposure along a scan line to reduce the visibility of the banding artifacts.

A multipass printing apparatus is characterized by a computer-implemented controller that controls printing operation so that, on any given pass, the number of selected print locations onto which printing ink is deposited by each of N nozzles varies from nozzle to nozzle. The variation is governed in accordance with a weighted smoothing spline function, particularly a polynomial B-spline function of the order “j”, where j is a value equal to one less than the number of passes.

A laser scanning assembly generates a laser beam and scans the laser beam through a plurality of scan lines to form desired dots. Each scan line is positioned to overlap an adjacent scan line and each dot includes a plurality of segments. The scanning assembly scans the laser beam through multiple scan lines to fully discharge each segment of each dot. The laser scanner assembly would typically be part of a laser printer.