Abstract: A method of edge enhancing a digital image having pixels which reduces the visibility of false edge contours and includes acquiring a digital image; computing an edge boost record having positive and negative boost values for different portions of the edge regions in a digital image; modifying the edge boost record by applying an adaptive blur kernel to the pixels of such edge boost record; and applying the modified edge boost record to the digital image to provide an edge enhanced digital image which reduces the visibility of false edge contours.

Abstract: A method for selecting an aim curve for a desired medium having a predetermined maximum density, including selecting an aim curve from a family of aim curves for a different medium having a lower predetermined maximum density than that of the desired medium, the aim curve having shadow, midtone, and highlight regions; varying the shadow contrast in the shadow region of the selected aim curve to produce a different aim curve; and determining the different aim curve with the desired medium that has an improved shadow contrast that will produce prints with reduced flare and permits a better fit of the dynamic range of the original scene to the dynamic range of the medium.

Abstract: A method for edge enhancing a digital image having pixels includes computing parameters for at least two orientations for each pixel in the stored digital image; using the computed parameters to form a classifier value for each such orientation and using such classifiers to determine the pixel classification based on such classifiers; and deriving a boost value according to the determined pixel classification.

Abstract: A method of edge enhancing a digital image having pixels, includes acquiring a digital image; computing an edge boost function having positive and negative boost for different portions of the edge of the digital image; adjusting the edge boost function to produce a modified edge boost function such that the gain of the negative boost is greater than the gain of the positive boost; and applying the modified edge boost function to the digital image to provide an edge enhanced digital image.

Abstract: In apparatus for processing a digital color image value originally obtained from an image sensor or the like having color image pixels aligned in rows and columns having diagonal pixels with sufficient information to permit luminance or chrominance estimation the digital image having at least three separate color values but only one color value for each image pixel location, such apparatus computing the luminance or chrominance values for each image pixel. The apparatus stores the digital image and includes a processor operatively associated with the stored image and responsive to said stored measured digital color image values for computing low frequency luminance or chrominance values. In response to the computed low frequency luminance or chrominance values the Laplacian second-order and gradient values in at least two image orientations are computed from neighboring image pixels.

Abstract: A method which substantially maintains the exposure latitude contained in one or more digital images captured in linear form and which uses an output device with a predetermined aim curve for producing visual images from such digital image includes the steps of selecting a particular reference portion of the scene corresponding to the digital image and adjusting the code value of such reference portion to a code value corresponding to a desired density and which corresponds to a point on the aim curve and changing the remaining code values of the digital image based upon the selected code value of the point on the aim curve so that a new digital image in linear form is produced; transforming the new digital image to form a third digital image which has code values based on the aim curve; and producing visual images by the output device in response to the transformed third digital image.

Abstract: Apparatus is disclosed for processing a digitized image obtained from an image sensor having color photosites aligned in rows and columns that generate at least four separate color values but only one color value for each photosite location, adjacent rows of values for each photosite being combined so that for each pair of photosites there is a single color value which is a combination of at least two different color values. In this apparatus, the combined single color values are used to produce Laplacian values for each pair of photosites. Also, the color signal values corresponding to adjacent pairs of photosites and the Laplacian values are used to produce a luminance value corresponding to each pair of photosites.

Abstract: Apparatus is described for processing a digitized image signal obtained from an image sensor having color photosites aligned in rows and columns that generate at least three separate color values but only one color value for each photosite location, and a structure for interpolating color values for each photosite location so that it has three different color values. The apparatus includes a memory for storing the digitized image signal and a processor operative with the memory for generating an appropriate color value missing from a photosite location by the interpolation of an additional color value for such photosite locations from color values of different colors than the missing color value at nearby photosite locations.

Abstract: A color filter array for an image sensor which has a plurality of pixels is disclosed. The color filter array includes a plurality of color pixel kernels, with each kernel having a plurality of pixels arranged in the following pattern______________________________________ M G C Y G M Y C Y C G M C Y M G ______________________________________wherein:M is magenta;G is green;C is cyan; andY is yellow.

Abstract: Apparatus is described for processing a digitized image signal obtained from an image sensor having color photosites aligned in rows and columns that generate at least three separate color values but only one color value for each photosite location, structure for interpolating color values for each photosite location so that it has three different color values. The apparatus includes a memory for storing the digitized image signal and a processor operative with the memory for generating an appropriate color value missing from a photosite location by the interpolation of an additional color value for such photosite locations from color values of different colors than the missing color value at nearby photosite locations.

Abstract: Apparatus described for processing a digitized image signal obtained from an image sensor having red, green, and blue color photosites aligned in rows and columns that generate at least three separate color values but only one color value for each photosite location. An arrangement is disclosed for averaging existing green values for green photosite locations which includes structure for storing the digitized image signal, defining green classifiers based upon adding the Laplacian second-order values, and the gradient values to define a classsifier, and modifying a measured green pixel based upon adjacent pixel classifiers. The apparatus further includes structure for determining which classifiers represent a pixel neighborhood of slowly changing scene detail, and replacing the measured green values for a green photosite location with an average of surrounding predicted green pixels as a function of the number of classifiers which are below a predetermined value.

Abstract: Apparatus is described for processing a digitized image signal obtained from an image sensor having color photosites aligned in rows and columns that generate at least three separate color values but only one color value for each photosite location, a structure is provided which interpolates color values for each photosite location so that it has three different color values. The apparatus includes an image buffer for storing the digitized image signal and a processor operative with the buffer storing means for generating an appropriate color value missing from a photosite location by the interpolation of an additional color value for such photosite locations from color values of different colors than the missing color value at nearby photosite locations.

Abstract: A method and associated apparatus is implemented for utilization in a halftone printing system to permit a halftone dot to be written with multiple density levels. These multiple density levels are used to from a variable density dot edge profile. This implementation is particularly adapted for use with systems that represent halftone dots with an envelope that is formed from a combination of straight lines that are drawn from tangent points, on the outer periphery of the dot, through reference axis for the dot. The intersection points of the tangent lines on the reference axis define the size (density) of the dot. The intersect points are stored as sets of digital values for each size dot to provide a unique representation set that is used to reconstruct a selected dot size for the printing of a halftone image.

Abstract: A method and associated apparatus is implemented in a halftone printing system that permits a halftone dot of the type that is represented by an envelope that is formed from a combination of straight lines that are drawn from tangent points to be position modulated by a displacement engine to introduce noise into the screener.

Abstract: An apparatus and method are implemented in a halftone printing system utilizing logic blocks that permit a halftone elliptical dot to be represented by an elliptical envelope that is formed from a combination of straight lines that are drawn from tangent points, on the outer periphery of the elliptical dot, through reference axis for the elliptical dot. The intersection points of the tangent lines on the reference axis define the size (density) of the elliptical dot. Storing the intersect points as sets of values for each size elliptical dot provides a unique representation set that is used to reconstruct a selected elliptical dot size for printing a halftone image.

Abstract: A tile-oriented technique and associated apparatus for manipulating a continuous tone (contone) image through image rotation, anamorphic scaling and digital halftone screening for use in illustratively implementing a page description language. Specifically, an incoming contone image is first partitioned into aligned non-abutting tiles (e.g. 215.sub.1, 215.sub.2, . . . , 215.sub.9). Overlapping blocks (e.g. 217.sub.1, 217.sub.2, . . . , 217.sub.9) are then defined which will hold output data for corresponding tiles. Two dimensional sampling increments, in fast and slow scan directions, are defined to relate movement between successive pixels in an output block to movement between corresponding pixels in the contone image. Similar, though independent, sampling increments, also in the fast and slow scan directions and based in part upon screen angle and screen ruling, are defined for movement between successive pixels in a halftone reference cell.

Abstract: An apparatus, implemented in a halftone printing system, permits a halftone dot to be represented by an envelope that is formed from a combination of straight lines that are drawn from tangent points, on the outer periphery of the dot, to a reference axis for the dot. The intersection points of the tangent lines on the reference axis define the size (density) of the dot. The apparatus addressably stores the intersect points as sets of values for each size dot to provide a unique representation set that can be accessed to reconstruct a selected dot size for printing a halftone image.

Abstract: A method is implemented in a halftone printing system that permits a halftone dot to be represented by an envelope that is formed from a combination of straight lines that are drawn from tangent points, on the outer periphery of the dot, through reference axis for the dot. The intersection points of the tangent lines on the reference axis define the size (density) of the dot. Storing the intersect points as sets of values for each size dot provides a unique representation set that is used to reconstruct a selected dot size for printing a halftone image.

Abstract: A tile-oriented technique and associated apparatus for manipulating a continuous tone (contone) image through image rotation, anamorphic scaling and digital halftone screening for use in illustratively implementing a page description language. Specifically, an incoming contone image is first partitioned into aligned non-abutting tiles. Overlapping blocks are then defined which will hold output data for corresponding tiles. To effect rotation and anamorphic scaling of the contone image, two-dimensional sampling increments, in fast and slow scan directions, are defined to relate movement between successive pixels in an output block to movement between corresponding pixels in the contone image. Similar, though independent, sampling increments, based in part upon screen angle and screen ruling, are defined for movement between successive pixels in a halftone reference cell. Incremental sampling occurs in the contone image to yield a corresponding sampled contone value.

Abstract: Apparatus and an accompanying method for use therein are disclosed for suppressing a screener induced Moire pattern that would otherwise appear in a reproduced color image generated by a raster based marking engine (20). This Moire pattern results from successively sampling a stored bit-mapped font pattern in a grid like raster based writing pattern in order to produce a visual depiction of the stored font pattern in the image. Specifically, this Moire is suppressed by forming an address, for use in successively accessing each desired bit in the stored font pattern, in which the address is formed of at least two portions in which each portion is generated through a summation of an orthogonal positional value with a corresponding specific amount of noise.