Abstract: A method of enhancing resolution in an electronic imaging device includes capturing an electronic image through a fisheye lens with a photodetector at a resolution native to the photodetector. A resolution is selected that is higher than the native resolution of the photodetector. The electronic image is processed to produce a new electronic image at the higher resolution. A fisheye effect caused by the fisheye lens is removed during processing.

Abstract: A method and apparatus for de-screening a halftone image, therefore allowing the recovery of an approximation of an original image, is disclosed. A method according to one embodiment first performs a screen conversion filter upon a scanned representation of the halftone image to produce an intermediate image. This method then performs a line smoothing filter upon the intermediate image to produce an approximation to the original image. In an alternate embodiment, the method performs a single convolution filter upon a scanned representation of the halftone image to produce an approximation to the original image. In this embodiment, the single convolution filter is equal to the resulting convolution of first performing a screen conversion filter and then performing a line smoothing filter.

Abstract: An image reading apparatus and method are provided which precisely correct shading due to dispersion of the spectral sensitivity characteristic of a reading area of a reading device. Second correction values for correcting, for each of R, G and B, shading due to partial dispersion of spectral characteristics of color separation filters are respectively set and stored for each film type and for each of a plurality of blocks forming an image, on the basis of results of reading a film for correction value setting. Then, from the stored second correction values, correction values corresponding to a type of a film which is an object of reading are retrieved to derive correction values for each pixel by interpolation. The derived correction values for each pixel are added to first correction values for correcting shading due to irregularity in the amount of light or the like.

Abstract: Documents are read and the read image data and the information about the size of the document is stored in a memory. A factor of enlargement/reduction is calculated based on the stored size information. An image processor 204 interpolates the image data based on the calculated enlargement/reduction factor and reproduces the enlarged/reduced document.

Abstract: In the image processing device, method and system of the present invention, a destination identifier of an image file is stored, the destination identifier indicating one of a plurality of external stations as a destination station which receives the image file from the image processing device through a network. At least one of a sender identifier of the image file, a subject identifier of the image file and a scan condition of the image file is stored. The image file is transmitted, together with at least one of the sender identifier, the subject identifier and the scan condition, through the network to one of the external stations indicated by the stored destination identifier.

Abstract: Optimal rehalftone screen frequencies are found by searching frequency space for points that are maximally spaced from significant frequency components of an input image halftone screen or screens. Selecting a rehalftone screen having a maximally spaced frequency produces moiré of the highest frequency possible. High frequency moiré are visually unobjectionable. Optimal rehalftone frequencies may be found near the maximally spaced points where system or other constraints limit the usefulness of the maximally spaced points. Rehalftone screen frequencies in the range of about 1.4 to about 1.8 times the fundamental frequency of the input image halftone screen are often optimal. A rehalftone screen frequency of 1.5 times the fundamental frequency of the input image halftone screen is often optimal when the input image is monochrome and uses a dot screen.

Abstract: This invention is to correct a difference of dot gain between output devices. This invention for converting binary data for a first output device to binary data for a second output device includes the steps of: converting the binary data for the first output device to multi-value data; correcting the multi-value data so that an output density by the second output device becomes equal to an output density by the first output device; and converting the corrected multi-value data to the binary data for the second output device. As stated above, by carrying out the correction so that the output density of the first output device coincides with the output density of the second output device, the user can obtain the same output result without giving consideration to a difference between output devices.

Abstract: A method is provided for rendering a color image with a plurality of separations with a halftone process using a single screen. The screen is comprised of a plurality of pixel locations with associated threshold values and the image is comprised of a plurality of separation values. The method includes the steps of rendering a first one of the plurality of separations in accordance with the screen, wherein the plurality of pixel locations are turned on or off at a given pixel location based on a comparison of the image separation value at that pixel with the screen threshold value. The rendering of the next color separation is made in accordance with the rendering of the first separation and the screen, wherein for constant image separation values, pixel locations are turned on for the separation at pixel locations disposed in a highest available luminance region having a lowest available threshold value.

Abstract: A method, apparatus, and computer software product to reproduce an input image on a proofing device including accurately reproducing color substantially matching the screening properties of an imaging process that includes screening. The proofer may use a different number of colorants and/or different colorants than the printing colorants of the imaging process. The proofer also may be capable of continuous tone output or may be a screened output device. The proofer also may be a computer screen.

Abstract: The invention provides a procedure that is applicable to various halftoning methods, which minimizes image distortion introduced by the halftoning process. The procedure involves maintaining specific relationships between the halftone pattern and the phase and resolution of the input image. Specifically, that the halftone pattern is designed such that it does not bias tone reproduction with respect to the location of the input image pixels—each input pixel should be given equal weight when filtered by the halftoning process. This suggests a 1 to 1 relationship between each pixel of the input image and the corresponding tone output produced by the halftoning process. The procedure results in improved print quality, manifested by avoidance of certain types of moiré which are commonly associated with halftoning, as well as improved reproduction of edges and image details.

Abstract: A halftone dot threshold data rewriting unit reads halftone dot threshold data corresponding to the output resolution of a printed image generating apparatus which has been set by an output resolution setting unit, from a halftone dot threshold data storage unit, rewrites the read halftone dot threshold data into halftone dot threshold data corresponding to the output resolution of a proof image generating apparatus, and supplies the rewritten halftone dot threshold data to a binary image generator. The binary image generator compares continuous tone image data with the halftone dot threshold data, generates binary image data, and supplies the generated binary image data to an exposure recorder, which generates a proof image corresponding to the output resolution of the printed image generating apparatus.

Abstract: Image data read by an image read section and digitized is temporarily retained in an input buffer of a printer. A control section determines the contents of image processing based on print setting specified from an instruction section and controls the compression and decompression timings of the image data in response to the image processing contents. To execute enlargement processing, the image data is compressed and stored, then enlarged; to execute reduction processing, the image data is reduced, then compressed and stored, whereby the memory resources can be used effectively.

Abstract: What is disclosed is an image path that advantageously uses halftone classification to select appropriate mappings in gray-scale management and color management operations. The tags generated in the scanner help identify different classes of halftones. One is selected from several pixel-value mappings to provide proper compensation. That is, the one-dimensional and multi-dimensional pixel-value mappings within the color management module are selected based on halftone classification tags from the scanner. The tagging is either one bit that indicates “Low Frequency Halftone” and “Not LFHT”, or, more preferably, the tag is multi-bit indicating a frequency bin that contains the frequency of the input halftone. Additionally, the multi-bit tag can indicate particular halftone screen types, such as dot screens, line screens, stochastic screens or error diffusion.

Abstract: A method and system for elimination of spatial artifacts in digital imaging. Aperiodicity is applied to periodic data to mitigate spatial artifacts. The data can be received aperiodically and reformatted to be rendered by a periodic output device. The data can be received in periodic format and rendered on an aperiodic output device. The system has aperiodic input and output devices.

Abstract: The invention provides a procedure that is applicable to various halftoning methods, which minimizes image distortion introduced by the halftoning process. The procedure involves maintaining specific relationships between the halftone pattern and the phase and resolution of the input image. Specifically, that the halftone pattern is designed such that it does not bias tone reproduction with respect to the location of the input image pixels—each input pixel should be given equal weight when filtered by the halftoning process. This suggests a 1 to 1 relationship between each pixel of the input image and the corresponding tone output produced by the halftoning process. The procedure results in improved print quality, manifested by avoidance of certain types of moiré which are commonly associated with halftoning, as well as improved reproduction of edges and image details.

Abstract: A method of providing an image for printing at a predetermined bi-level dot resolution which corresponds to a predetermined continuous tone resolution, the method including the steps of: receiving a first data set indicative of the image, the data set being in a Bayer format of a first resolution; converting the first data set into a second data set of the predetermined continuous tone resolution; converting the second data set into a third data set of the predetermined bi-level dot resolution; and making the third data set available to a printer at the predetermined bi-level dot resolution.

Abstract: A raster image processing system (20) for producing the appropriate number and set of halftoned color separations for a select output device (24) is disclosed. The raster image processing system (20) includes a processing unit (30), an interpreter (32) and a color combiner (34). The interpreter (32) and color combiner (34) are application processes that are controlled by software running on the processing unit (30). The processing unit (30) identifies the number and set of colorants used to describe input image data and the number and set of halftoned color separations that a select output imaging device (24) is capable of rendering. The interpreter (32) converts the input data describing an image that is composed of “N” colorants into “N” halftoned color separations. The color combiner (34) thereafter converts the N halftoned color separations into “M” halftoned color separations that are ideally suited for the particular output device (24) chosen by a user of the system.

Abstract: The result of integrating a halftone dot-shape can be clustered. When the edge of the halftone dot-shape extends across a “vertical” edge of a window, the window is altered until the edge of the halftone dot-shape no longer crosses either vertical edge of the altered window. The image density of the portion of the halftone dot-shape contained within the altered window is determined. The block of image density of the portion of the halftone dot shape contained within the altered window is aligned with the right edge, the left edge, split between the left and right edges, or clustered in the “center” of the altered window. An amount of the determined block that extends into the original sample window is determined. This amount extending into the original window determines the amount of image density to be generated in the final output image based on that sample location of the window.

Abstract: A method for simulating high resolution printing by converting high resolution bits of a binary image to sub-pixel high addressable bits is presented. A first image is received having a first fast-scan resolution and a first slow-scan resolution. The first image is converted to a second image having a second fast-scan resolution and a second slow-scan resolution. The second fast-scan resolution of the second image is greater than the first fast-scan resolution of the first image. Also, the second slow-scan resolution of the second image is less than the first slow-scan resolution of the first image. In addition, a method of generating a high addressable halftone image from a high resolution binary image for marking on an image output terminal is presented. A high addressable halftone threshold array having a first high addressability value is converted to a balanced halftone threshold array having a first resolution in a fast-scan direction and the same first resolution in a slow-scan direction.

Abstract: The method of the invention improves the presentation of pixel data images in output documents. The method is implemented by a pipeline of image processing actions which, among others, includes an edge evaluation step wherein neighborhoods of pixel data are examined to derive edge values that are indicative of an edge presence in the respective neighborhood. Each edge value is further indicative of the intensity of the edge. The edge evaluation action further determines scaling parameters which enable later distribution of a neighborhood's center pixel tone value to subpixels that are created during a scaling action of the center pixel.

Abstract: One method for halftone image watermarking assigns halftone watermark dot values to pseudorandom locations in an image and diffuses the error of the watermark to neighboring pixel locations of these dots. This method may be used in conjunction with a robust watermark spread throughout image before embedding the halftone watermark. The robust watermark carries a key used to decode the halftone watermark. Another method for halftone image watermarking computes a watermark image at the resolution of a halftone image. The method modulates the halftone image with the watermark image.

Abstract: A digital signal processing (DSP) method to process rendered text in order to achieve up to 300% of the horizontal resolution on any suitable digital display devices such as LCD, PDP and DLP. When the text is rendered, a single picture element (a “pixel”) of a matrix display screen is actually composed of three “sub-pixels”: one red, one green, and one blue (RGB or BGR). Taken together this sub-pixel triplet makes up what has been traditionally thought of as a single pixel. By staggering and processing the sub-pixel elements horizontally, font resolution is effectively increased to the maximum of 300%. There are three processing steps involved. First, the color image is expanded to a gray scale image having triple the number of horizontal pixels as the original image by interleaving the sub-pixels. Next, a black and white text/graphics (TG) detector is deployed to identify the TG of interest in the gray scale image.

Abstract: A method of modifying screened image data so that there is no visible seam when the image is printed repeatedly in a circumferential direction, for example using a drum output device. One version applicable to images screened using a supercell includes cutting the image so that the image size in the circumferential direction is an integral number of screen supercells. Another version includes displacing halftone dots in a neighborhood of the seam such that the seam is not visible in a repeated print.

Abstract: Optimal rehalftone screen frequencies are found by searching frequency space for points that are maximally spaced from significant frequency components of an input image halftone screen or screens. Selecting a rehalftone screen having a maximally spaced frequency produces moiré of the highest frequency possible. High frequency moiré are visually unobjectionable. Optimal rehalftone frequencies may be found near the maximally spaced points where system or other constraints limit the usefulness of the maximally spaced points. Rehalftone screen frequencies in the range of about 1.4 to about 1.8 times the fundamental frequency of the input image halftone screen are often optimal. A rehalftone screen frequency of 1.5 times the fundamental frequency of the input image halftone screen is often optimal when the input image is monochrome and uses a dot screen.

Abstract: Using a resolution supplied from an image output apparatus and ruling information supplied from a ruling information storage unit, a screen ruling of threshold data stored in a threshold data storage unit is determined, and threshold data which provides a screen ruling closest to a desired screen ruling supplied from a screen ruling input unit is selected and supplied to a binarization processor which is supplied with multivalued image data from an image processing apparatus. The binarization processor compares the selected threshold data and the multivalued image data to generate binary image data.

Abstract: A method, computer program product, and a program storage device readable by machine, for repurposing images includes classifying the pixels of a binary image as being either halftone image pixels or non-halftone image pixels, further processing the halftoned image pixels with halftone image pixel processing and combining the outputs of the halftone image pixel processing and non-halftone image pixel processing to prepare the images for a second purpose such as a second printer. The processing that classifies the binary pixels as being either halftone image pixels or non-halftone image pixels segments the image into regions of halftone image pixels and regions of non-halftone image pixels. The processing of regions of halftone image pixels first constructs an intermediate gray scale representation of the regions of halftone image pixels.

Abstract: A method of identifying a scanned image includes creating an original image with a plurality of halftone resolutions. The original image is then scanned at a scanning resolution to create the scanned image. When the scanning resolution is related to at least one of the plurality of halftone resolutions of the original image, a stamp is generated in the scanned image.

Abstract: A method and system for designing a plurality of correlated stochastic screens or conjugate screen portions intended for use in color halftoning of a corresponding plurality of color separations. A merit function is associated with each screen or screen portion. The merit function represents a measure of the desirability of the screen, particularly with regard to maximizing ink dispersion and optimizing spatial frequency response. An additional merit function value is associated with a combination of the screens and screen portions. Additional merit function represents a measure of desirability of the screen combination with regard to ink dispersion and combined spatial frequency response. The merit functions are iteratively applied to possible screens until an optimized merit value is calculated. The screens are selected that correspond to the optimized merit value. The image is generated using the selected screens in a conventional color halftoning process with a plurality of color separations.

Abstract: A high addressable multibit screening device and method for use in a PDL interpreter environment achieve improved printing resolution and quality. A PDL interpreter receives a PDL document from a host source, which identifies one or more objects that can be fully toned (black) or partially toned (line art or images). Each of these objects can be processed differently. Fully toned objects are processed within the interpreter and directly output in a predetermined output. Partially toned objects are sent to a high addressable screening module within the interpreter for processing prior to outputting in a desired output format. The high addressable screening module screens the partially toned objects to obtain multibit screened data for output.