摘要:
Embodiments described herein are directed to detecting and/or measuring distortions of substrate media that can occur during a printing process. The distortion can be detected and/or measured using a composite image generated from a reference image having a first periodic pattern and print image, disposed on a test substrate media, having a second periodic pattern. The first and second periodic patterns are specified so that the composite image includes a moiré pattern having moiré fringes resulting from interference between the first periodic pattern associated with the reference image and the second periodic pattern associated with the print image. The moiré fringes can be used to detect and calculate an amount of distortion of the test substrate media.
摘要:
As set forth herein, computer-implemented methods and systems facilitate watermarking documents and/or images using 2nd generation stochastic halftoning. The watermark is used to spatially vary the gray level at which a frequency modulation-to-amplitude modulation transition occurs. The encoding algorithm uses as inputs a contone image and a watermark. The visibility of the watermark is controlled by the magnitude of the difference between the AM-to-FM transition threshold values.
摘要:
As set forth herein, computer-implemented methods and systems facilitate halftoning using a parametrically controlled spot function based on triangle tessellation, which in turn facilitates dot growth control of periodic halftone using an irregular seed structure. The spot function determines the shape of the halftone dot used to reproduce a given pixel. The spot function is well suited for growing halftone dots arrayed on a non-regular grid and can also be used for grids with regular order. The spot function includes adjustable parameters for controlling its sharpness and slope.
摘要:
When restoring a scanned halftone image of a damaged document, parameters of the halftone structure (geometry) are estimated, as is an intended contone gray level for damaged portions of the image. Locations of halftone cell tiles in the scanned image are determined based on the halftone structure, and a halftone profile model is generated using the estimated halftone parameters and contone information. Image segments are aligned using global features for coarse alignment and halftone structure for fine alignment, such as in cases where the scanned halftone image contains unconnected fragments. Missing parts of the damaged document image are filled in using the halftone profile model and estimated contone values.
摘要:
As set forth herein, computer-implemented methods and systems facilitate halftoning using boundaries and centers of a polygonal tiling with a parameterized spot function that operates within the tiles. Defining the halftone structure includes defining the polygonal tiling with a specification of the polygon boundaries and center, and setting and applying parameters of the spot function, which utilizes center-to-boundary distances. The tiling can be defined explicitly, by defining a tile structure, or providing centers, one per polygon, and vertices for the polygons. The vertices and centers are used to generate the polygon boundaries. The polygonal tiling can be regular (e.g., repetitive) or irregular, and can also be varied in a manner adapted to the image content or to data that is being embedded.
摘要:
Disclosed are moiré-free color halftoning methods, apparatus and systems to digitally reproduce an original color image. The disclosed embodiments are particularly useful for rendering a color image with a color printing device. According to one exemplary embodiment, an image forming method utilizes three or four rotated hexagonal screens which can include regular shaped hexagon screens or convex tessellated hexagon screens.
摘要:
As set forth herein, computer-implemented methods and systems facilitate halftoning by adapting 2nd generation halftone techniques to the spatial frequency content of an image utilizing a spot function introduced in conjunction with a technique for determining seed locations, which results in halftone images exhibiting improved edge and detail rendition. A dominant orientation of pixels in an input image is employed to select a pre-generated stochastic screen used to determine the seed locations.
摘要:
Provided is a 3-colorant DOD (dot-off-dot) periodic halftone geometry used to render an image. The DOD 3-colorant halftone geometry includes a base colorant halftone screen with hexagonally tiled halftone dots arranged in a hexagonal pattern, the hexagonally tiled halftone dots having a first fundamental frequency vector Vh1, a second fundamental frequency vector Vh2, and a third fundamental frequency vector Vh3, where Vh3 is substantially equivalent to Vh1+Vh2.
摘要翻译:提供了用于渲染图像的3-着色剂DOD(点 - 点)周期性半色调几何。 DOD 3着色剂半色调几何形状包括具有以六边形图案排列的六角形平铺半色调点的基础着色剂半色调筛网,六边形平铺半色调点具有第一基频矢量Vh1,第二基本频率矢量Vh2和第三基频矢量 Vh3,其中Vh3基本上等于Vh1 + Vh2。
摘要:
Disclosed are moiré-free color halftoning methods, apparatus and systems to digitally reproduce an original color image. The disclosed embodiments are particularly useful for rendering a color image with a color printing device. According to one exemplary embodiment, an image forming method utilizes three or four rotated hexagonal screens which can include regular shaped hexagon screens or convex tessellated hexagon screens.
摘要:
When restoring a scanned halftone image of a damaged document, parameters of the halftone structure (geometry) are estimated, as is an intended contone gray level for damaged portions of the image. Locations of halftone cell tiles in the scanned image are determined based on the halftone structure, and a halftone profile model is generated using the estimated halftone parameters and contone information. Image segments are aligned using global features for coarse alignment and halftone structure for fine alignment, such as in cases where the scanned halftone image contains unconnected fragments. Missing parts of the damaged document image are filled in using the halftone profile model and estimated contone values.