Osa binary display of images when spot size exceeds step size
As described above, the present invention is a halftone rendering system which accomplishes its function by a pixel-by-pixel comparison of a gray scale image against a "blue noise" mask. Threshold matrix, storage unit for storing threshold matrix as data, and raster image processor incorporating storage unit. Still more particularly, it is an object of this invention to provide a system for the halftone rendering of a gray scale image which can be implemented either digitally or optically. Method and arrangement for eliminating flicker in interlaced ordered dither images.
Threshold matrix, storage unit for storing threshold matrix as data, and raster image processor incorporating storage unit. Method and apparatus for reducing artifacts in halftone images using gray balance correction. Thus, for a B-bit image array f i,jthe blue noise mask array m i,j is a B-bit array such that, when thresholded against f i,jup to 2 B levels of varying distribution of black and white dots can be represented on a rectangular grid. That procedure is shown in FIG. An additive photographic process may also be utilized in which osa binary display of images when spot size exceeds step size blue noise mask is added to the gray scale image at the film plane, for example, by a double exposure process.
Such differences include differences in contrast, between each area to be isolated as a substantially transparent area, and at least one particular background area surrounding each area to be isolated. Apparatus for representing continuous tone and high contrast images on a bilevel display. Such method produces a pleasing pattern without any blurring of the image.
However, the filtered pattern is no longer binary. EQU2 where R, as before, is the distance between addressable points on the display and the gray level g is normalized between 0 and 1. A combination of a comparator and the computer readable memory device of claim 43, said comparator having a first input, a second input, and an output, said first input responsive to said memory device. Methods and apparatus for modifying image data based on identification of marking process.
That makes it possible to construct specialized blue noise masks for a particular output printer. A machine comprising a computer readable storage device which stores an array for use in halftoning image information, said array comprising a non-white noise, locally aperiodic, thresholdable dither matrix and a comparator responsive to said dither matrix. In that manner, the blue noise mask disclosed herein can be applied simply to the component colors of RGB, CMYK and others for color printing. The Maxval is the maximum Value of the blue noise mask for example, for the 8-bit blue noise mask.
Halftoning renders the illusion of various shades of gray by using only two levels, black and white, and can be implemented either digitally facsimile machines, laser printers or optically newspaper printing. A machine comprising a computer readable storage device which stores a dither matrix for use in halftoning image information and a comparator responsive to said computer readable storage device, said dither matrix comprising at least one array, said at least one array, when thresholded at a number of levels produces a number of dot profiles, osa binary display of images when spot size exceeds step size plurality of said number of dot profiles each having a power spectrum substantially characteristic of a blue noise power spectrum for the level at which such dot profile is produced. After step or if a negative determination is made at stepthen the values of the modified blue noise mask b' i,j are written into memory at step
Experimental verification, SPIE vol. The machine of claim 66, wherein said array comprises a blue-noise, locally aperiodic thresholdable matrix. Table of Contents, Introduction, Monochrome Reproductions 2. Steinberg " An Adaptive algorithm for spatial greyscale ", Proc.
Screen Frequencies and Screen AnglesSections: Method and apparatus for halftone rendering of a gray scale image using a blue noise mask. A variation of this method of separately halftoning the different color planes of an image is to use the inverse of a blue noise mask for one color, where the inverse is defined as Maxval-BNM for each pixel.