Abstract: Optical properties of a screen on which an image is being projected are considered. A patterned surface is given a predetermined pattern of color pixels whereby a degree of wavelength selectivity is employed to improve the color qualities of the projected image. A system is provided wherein there is a matching of emission characteristics of a projector to the screen's reflective characteristics.

Abstract: A method and apparatus for edge-preserving processing of digital images includes selecting an input pixel from a digital image, choosing a set of neighboring pixels from an area around the input pixel according to a sparse matrix constructed according to a distribution, determining the similarity in value of each neighboring pixel to that of the input pixel according to a metric, and calculating a weighted average of the values of the neighboring pixels by weighting by a first smaller weight those pixels which are less similar to the input pixel and weighting by a second greater weight those pixels which are more similar to the input pixel.

Abstract: A projection screen for use in a projection system is described. In an embodiment of the present invention, a projection system includes a projector and a projection screen. The projector is configured to project an image composed of visible light in one or more ranges of wavelengths. The projection screen has a plurality of sub-pixels that reflect and/or transmit the one or more ranges of wavelengths to display the image and absorb visible wavelengths of light in at least one other range not included in the one or more ranges. One or more spaces are defined between adjacent sub-pixels that reflect and/or transmit the one or more ranges and the at least one other range.

Abstract: Processing of an image includes estimating a parameter for local color correction. The parameter estimation includes computing a cumulative histogram path length of the image.

Abstract: The invention is directed towards method and apparatus for performing local color correction. One embodiment of the invention is a two-part process. The first part derives an image mask from an input image. In some embodiments, the mask is an inverted, low-pass filtered, monochrome version of the input image. The second part combines the derived mask with the input image through a non-linear operation. In some embodiments, the combination operation is a variable exponential function that has the mask values as part of its exponent and the pixel values as part of its base.

Abstract: Gray component or undercolor in an input image is quantitatively determined, and reduced in amounts nonlinearly related to the quantity of undercolor. The reduced and added signals are applied to control printing by, preferably, scanning inkjet printheads. The total undercolor inking is a substantially monotonic function of the quantity of undercolor. Preferably the reducing and adding are performed in a subtractive-colorant color space, e.g. CMYK space. Preferably image data is initially accepted or generated in terms of additive RGB signals, and these are converted into the subtractive domain. Preferably the reducing and adding means operate only above an undercolor threshold of about twenty to thirty-five percent; and total inking is made between one hundred fifty and two hundred fifty percent when the signals are all gray component. Initial very gradual increases from a threshold are important, for consistent, smooth, regularized dynamic-response in tonal gradations.