Abstract: An annular window-shaped structuring element is provided for image processing to remove speckles from a scanned image. The window-shaped structuring element is composed of two differently sized squares sharing the same geometric center-point. The pixel to be analyzed with the structuring element is at the center-point. The structuring element is used in a method to remove speckles from binary, grayscale, and/or color images by first eroding the image, detecting speckles relative to other pixels in the image, and removing declared speckles. The method may additionally include a halftoning module to protect halftone images.

Abstract: Systems and methods that allow for anti-counterfeiting marks that carry user information and other data to be embedded into an original coupon design. The marks may be invisible, or visible but difficult to remove. At the receiving sides of the coupons, the embedded data are used to detect fraud and trace back the coupon users.

Abstract: System and methods provide a message, generated based on a message authentication code (MAC), embedded in a look-up table associated with an image. The embedding of the message does not affect the image. The message may be used to authenticate the image.

Abstract: This invention relates to an imaging device that extends the processing of resources to data having a greater bit-depth. A signal having data at the first bit-depth is received, and at least a portion of the data at the first bit-depth is converted into an estimated value that is at the second bit-depth. A residual that indicates a difference between the data and the estimated value is determined. The estimated value is processed through the resource to form processed data that is at the second bit-depth. The data is then substantially recovered at the first bit-depth from the processed data that is at the second bit-depth and based on the residual.

Abstract: A method of determining image skew in a scanned document includes scanning the image and determining on a pixel-by-pixel basis whether or not pixels are ON or OFF on scan lines and columns along both the fast and slow scan directions for a particular document rotation angle. Through one read of the image, image data is sampled simultaneously at a plurality of predetermined document rotation angles From the sampled data, the second order moment of the number of ON pixels is calculated as a function of document rotation angle for scan lines along both the fast and slow scan directions, yielding two independent skew angle estimates Skew angle estimates corresponding to valid second order moment data sets are compared and combined to provide a resultant skew angle estimate for the document.

Abstract: A method for dynamic range adjustment of image data of a captured image by determining a white point of an image. The method also involves determining a black point of the image, classifying pixels of the image, and determining an offset value for a pixel of the image based on the determined black point of the image and the determined classification of the pixel. Dynamic range adjustment of the image data is performed using the determined offset value for the pixels of the image and the determined white point of the image.

Abstract: A pixel classification method for classifying pixels of an image by determining a background intensity level of an image which is based on substantially all of the pixels of the image. The method also involves classifying the pixels of the image and checking the classification of the pixel based on the determined background intensity level of the image.

Abstract: A streak detection method and system in a fixed imaging array digital scanning system obtains image data from each of the plurality of rows in the at least one full color spectrum channel set of rows of positionally discrete sensors and integrates this data to produce an estimate of image data recorded by at least one clear channel row of positionally discrete sensors. A clear channel error signal is generated by the comparison to alert the operator to the presence of non-image data. The clear channel error signal may be refined to through a low pass column filtering process in order to filter out potentially erroneous clear channel error resulting from thermal, mechanical or other noise sources unrelated to image scanning. Stationary obstructions in the field of view of the imaging array, or defects in one or more sensors in the imaging array, are detected through this comparison which would otherwise appear repeatedly reproduced as streaks or lines in the reproduced output image.

Abstract: A method and system for image processing, in conjunction with classification of images between natural pictures and synthetic graphics, using SGLD texture (e.g., variance, bias, skewness, and fitness), color discreteness (e.g., R_L, R_U, and R_V normalized histograms), or edge features (e.g., pixels per detected edge, horizontal edges, and vertical edges) is provided. In another embodiment, a picture/graphics classifier using combinations of SGLD texture, color discreteness, and edge features is provided. In still another embodiment, a “soft” image classifier using combinations of two (2) or more SGLD texture, color discreteness, and edge features is provided. The “soft” classifier uses image features to classify areas of an input image in picture, graphics, or fuzzy classes.

Abstract: An image transfer apparatus for transferring an image on a sheet medium having a frame and a reader connected to the frame for reading the image on the sheet medium. The image moves relative to the reader in a process direction when the reader reads the image. A positioning system is connected to the frame for positioning the sheet medium at a predetermined skew angle relative to the process direction.

Abstract: In a machine-fed scanner, orientation angles of edges of an image bearing substrate are obtained and used to calculate image shear and/or skew. A running weighted average of the image skew may be kept in a memory. When a skew value is obtained for a given image, it may be determined whether the skew value is within a predetermined range. If the skew value is within the predetermined range, the skew value is used to determine an image revision to compensate for the skew, and the skew value is incorporated into the running weighted average skew. If the skew value is not within the predetermined range, it is discarded and the running weighted average skew is used to determine an appropriate image skew revision. The running weighted average of the shear may also be kept in a memory. A shear value is obtained for each image, and incorporated into the running weighted average shear. Shear revision is performed based on the running weighted average shear.

Abstract: A method and apparatus is provided for determining a halftone line screen frequency estimate f at a pixel of interest in an image formed of a plurality of pixels arranged in a regular array of rows and columns. A first single dimensional line screen frequency estimate fH is determined based on video values of a first set of pixels in a row of pixels in the scanned image. Next, a second single dimensional line screen frequency estimate fV is determined based on video values of a second set of pixels in a column of pixels in the scanned image. A two-dimensional halftone line screen frequency estimate f is calculated at each pixel of interest based on a norm of the first single dimensional line screen frequency estimate fH and on the second single dimensional line screen frequency estimate fV. A halftone line screen angle estimate a is calculated at each pixel of interest based on an arctangent of the ratio between the first and second single dimensional line screen frequency estimates.

Abstract: A method and apparatus are provided for determining a weighted average measured reflectance parameter Rm for pixels in an image for use in integrated cavity effect correction of the image. For each pixel of interest Pi,j in the image, an approximate spatial dependent average Ai,j, Bi,j of video values in a region of W pixels by H scan lines surrounding the pixel of interest Pi,j is computed by convolving video values Vi,j of the image in the region with a uniform filter. For each pixel of interest Pi,j a result of the convolving step is used as the reflectance parameter Rm. The apparatus includes a video buffer for storing the pixels of the original scanned image, and first and second stage average buffers for storing the computed approximate spatial dependent averages Ai,j, Bi,j. First and second stage processing circuits respectively generate the first and second stage average values Ai,j, Bi,j by convolving the video values of the image in a preselected region with a uniform filter.

Abstract: A system and method for processing image data converts a pixel of image data having a first resolution to a plurality of subpixels, the plurality of subpixels representing a second resolution, the second resolution being higher than the first resolution. The plurality of subpixels are thresholded to generate a group of subpixel values for each pixel and a threshold error value. It is then determined if the group of subpixel values from the thresholding process produce a pattern containing an isolated subpixel. If the group of subpixel values from the thresholding process produce a pattern containing an isolated subpixel, the group of subpixel vales is modified to produce a pattern without an isolated subpixel. The modification process produces a subpixel error value which is compensated for localized error before being diffused to adjacent pixels.

Abstract: A method of determining image skew in a scanned document includes scanning the image and determining on a pixel-by-pixel basis whether or not pixels are ON or OFF on scan lines and columns along both the fast and slow scan directions for a particular document rotation angle. Through one read of the image, image data is sampled simultaneously at a plurality of predetermined document rotation angles From the sampled data, the second order moment of the number of ON pixels is calculated as a function of document rotation angle for scan lines along both the fast and slow scan directions, yielding two independent skew angle estimates. Skew angle estimates corresponding to valid second order moment data sets are compared and combined to provide a resultant skew angle estimate for the document.

Abstract: An annular window-shaped structuring element is provided for image processing to remove speckles from a scanned image. The window-shaped structuring element is composed of two differently sized squares sharing the same geometric center-point. The pixel to be analyzed with the structuring element is at the center-point. The structuring element is used in a method to remove speckles from binary, grayscale, and/or color images by first eroding the image, detecting speckles relative to other pixels in the image, and removing declared speckles. The method may additionally include a halftoning module to protect halftone images.

Abstract: A system and method classify a pixel of image data as one of a plurality of image types. A first image characteristic value for the pixel, a second image characteristic value for the pixel, a third image characteristic value for the pixel, and a fourth image characteristic for the pixel is determined. Some of these determinations may be resolution dependent. The values from these determination are utilized in assigning an image type classification to the pixel. Moreover, if at least one of the image characteristic values is greater than a predetermined threshold value the pixel is classified as a halftone peak value.

Abstract: A method and system for image processing, in conjunction with classification of images between natural pictures and synthetic graphics, using SGLD texture (e.g., variance, bias, skewness, and fitness), color discreteness (e.g., R_L, R_U, and R_V normalized histograms), or edge features (e.g., pixels per detected edge, horizontal edges, and vertical edges) is provided. In another embodiment, a picture/graphics classifier using combinations of SGLD texture, color discreteness, and edge features is provided. In still another embodiment, a “soft” image classifier using combinations of two (2) or more SGLD texture, color discreteness, and edge features is provided. The “soft” classifier uses image features to classify areas of an input image in picture, graphics, or fuzzy classes.

Abstract: A method and apparatus are provided for use in single channel segmentation of color images for reclassifying pixels which were inappropriately classified as belonging to a “black” or “white” class. The apparatus includes a re-classification circuit receiving first classification data generated by a single channel segmentation circuit operative to classify pixels of a multi-color channel input image. The re-classification circuit selectively re-classifies pixels that were previously classified by the single channel segmentation circuit into an “other” segmentation class based on a comparison of classification data associated with the pixels relative to a set of predefined classification data types.

Abstract: A color conversion table designed to produce 0% under-color removal and a 100% under-color removal TRC are configured as a matched pair and are used to render an image from fuzzy detected color signals, including providing variable under-color removal to obtain fuzzy black conversion. The output of the color conversion table and the TRC are multiplied by a weighted value which depends on a value of a received neutral tag. The weighted outputs of the color conversion table and TRC are added such that a varying weighted output is generated. The generated output is used in image rendering to produce a smooth transition from a full color to monochrome, where variable amounts of under-color removal are obtained using the color correction table and TRC.