Abstract: An efficient technique is provided for determining a portion of a document corresponding to a captured image. Areas of a document in which the pattern is at least partially obscured are identified. A reference pixel in the image is selected, and an offset between the pixel and the pattern is determined. A pixel-by-pixel comparison is then made of the image with the document such that the reference pixel is only compared with locations in the document that are both within the identified areas and have the determined offset from the pattern. The comparison with the highest correspondence between the image pixels and the electronic document then identifies the position of the reference pixel relative to the electronic document.

Abstract: The present invention provides an improved method and system for load-out of a topsides onto at least two float-over barges without requiring an intermediate transportation barge. The topsides and float-over barges create a catamaran system that can be used to install the topsides to an offshore structure, such as a Spar hull, using a float-over method. The load-out process offers several advantages and can be less time-consuming and less expensive than a typical procedure using the intermediate transportation barge.

Abstract: A system for determining a commutation state for a brushless DC motor includes flyback detection circuitry that detects a flyback condition for each of a plurality of motor commutation states for the multiphase motor. The flyback detection circuitry provides a detection signal indicative of the detected flyback condition for each of a plurality of motor commutation states for the substantially stationary multiphase motor. A timer provides a time value based on the detection signal, the time value indicating a duration for the flyback condition for each respective motor commutation state. Logic is determines the commutation state for the multiphase motor based on the time value for each of the plurality of motor commutation states.

Abstract: Methods and apparatuses that synchronize a paper document to an associated digital document by establishing a mapping. An embedded interactive code (EIC) Document is created as a digital file that serves as an intermediate tier between the paper document and the digital document. Both the paper document and the EIC document are generated while printing the paper document. The EIC document records the corresponding EIC array allocations and a unique document identification number. An image capturing pen may generate a stroke on any page of paper document. With the EIC document, the methods and apparatuses inform an application the page and location on the page of the stroke.

Abstract: In accordance with embodiments of the invention, embedded interaction code (EIC) symbols are recognized. EIC dots are generated based on effective EIC symbols, which have been generated by processing an image containing the EIC symbols, by obtaining graylevels of selected positions of the EIC-symbols. Rotated EIC dots are generated based on the EIC dots by determining which grid cells correspond to the EIC symbols and by determining which direction is a correct orientation of the EIC symbols. A homography matrix is updated with orientation information based on the EIC dots. EIC bits are extracted from the rotated EIC dots based on graylevels of selected positions of the rotated EIC dots.

Abstract: Disclosed embodiments of the invention relate to analyzing document images, which contain positionally encoded information, such as a maze-pattern watermark, and labeling the images based on a degree to which the document's content, such as text, occludes the position-encoding information. Depending on the degree of such occlusion, it may not be possible to extract enough position-encoding bits from a camera-captured image of the document to determine the camera-captured image's location within the document. An analysis-and-labeling module receives, as input, image data output by an image-generation-and-capturing module and off-line training data; performs analysis-and-labeling processing; and outputs image-label information. The results of document-analysis-and-labeling processing may be used for efficiently determining a location of a camera-captured image within a positionally encoded document.

Abstract: A method and apparatus for capturing information encoded within a surface, such as location information or document metadata, and associating the information with a document is described. The captured information may be obtained by a camera associated with a pointing or writing device having a camera, such as an image-capturing pen.

Abstract: Systems and methods that determine a path of a pen tip as the pen tip is moved across a document are described. The document is watermarked with a maze pattern from which encoded position information is determined. A sequence of images is captured by a camera that is located in a pen. The path of the pen tip is determined by decoding the associated maze pattern and by matching the captured images with document images. If the position coordinates of any frame that is associated with a stroke cannot be determined from m-array decoding, the frames are transformed and then matched with an area of a document image. Once the position coordinates of at least one frame is determined, the position coordinates of other frames are determined by matching the frames in a neighboring area.

Abstract: X-y positions of a digital pen's tip may be determined by using a calibration parameter to map the x-y positions of the respective centers of images captured by the pen's camera. The calibration parameter may be generated by iteratively calculating estimates of the calibration parameter. The iteratively calculated estimates may be based on a gradient of an error function of the iteratively generated estimates. Calibration input data may be produced by a user placing the pen tip in a fixed location on a surface, which may be a positionally encoded medium, such as paper, and then rotating the pen and/or moving the opposite end of the pen in various directions to capture multiple images for use in generating the calibration parameter. A user may perform such a calibration procedure without the need for complicated calibration equipment typically used in connection with conventional calibration techniques.

Abstract: A method and system for decoding data on a medium that is captured by an input device is described. The method decodes a symbol design, such as an embedded interaction code (EIC), on a display screen, such as a liquid crystal display (LCD). An image that is captured by an input device, such as a universal pen-type input device with a camera, is received. The captured image is processed to output an extracted bit stream. Position data and/or metadata information is decoded from the extracted bit stream and a position of the captured image with respect to a screen of the LCD is determined based upon the decoded position data. The EIC pattern may be recognized from LCD pixel grids and a bit stream of EIC bits may be extracted based upon the recognized EIC pattern.

Abstract: A technique is disclosed for determining a portion of a document corresponding to a captured image. A user employs a pen to create a stroke in a document, and images are captured by a camera mounted on the pen. The locations of some of the images are determined by, e.g., analyzing a pattern on the document captured by the image or by a pixel-by-pixel comparison of the image with the document. The locations of other images are determined by segmenting the sequence of images into groups corresponding to the shape of the stroke. Information relating to a located image in a segment is employed to determine the position of an unlocated image in the segment. This determined position is used for obtaining further information that may be used to determine the position of another unlocated image in the segment, and so on, until the segment is finished.

Abstract: Pre-processing techniques for processing an image to improve the distinctiveness of an information pattern captured in the image before the information pattern is analyzed in a decoding process. The brightness of an image first is normalized by dividing the image into blocks of areas, such as pixels. A brightness distribution value then is determined for each area of the image by fitting the brightness of its surrounding blocks using bilinear interpolation and extrapolation, and a normalized brightness value for each area can then be obtained by dividing the original brightness value by the brightness distribution value. Next, masks are created to distinguish the information pattern from content captured in the image. The masks may be generated based upon contrast differences between the brightness of pixels representing the information pattern, the brightness of pixels representing content, and the brightness of pixels representing the background of the writing medium.

Abstract: An efficient technique is provided for determining a portion of a document corresponding to a captured image. Areas of a document in which the pattern is at least partially obscured are identified. A reference pixel in the image is selected, and an offset between the pixel and the pattern is determined. A pixel-by-pixel comparison is then made of the image with the document such that the reference pixel is only compared with locations in the document that are both within the identified areas and have the determined offset from the pattern. The comparison with the highest correspondence between the image pixels and the electronic document then identifies the position of the reference pixel relative to the electronic document.

Abstract: An efficient technique is provided for determining a portion of a document corresponding to a captured image. Areas of a document in which the pattern is at least partially obscured are identified. A reference pixel in the image is selected, and an offset between the pixel and the pattern is determined. A pixel-by-pixel comparison is then made of the image with the document such that the reference pixel is only compared with locations in the document that are both within the identified areas and have the determined offset from the pattern. The comparison with the highest correspondence between the image pixels and the electronic document then identifies the position of the reference pixel relative to the electronic document.

Abstract: A method and system for compressing and displaying a digital ink trace. Raw ink data is smoothed, and sharp points of the smoothed line are found. Curve-fitting is then used to generate a mathematical expression that defines the line segments between adjacent sharp points. The ink trace then is represented by a backbone spline that includes the sharp points and the mathematical expressions for the line segments. Thickness information, such as pressure or acceleration information, is combined with the backbone spline to provide a compressed ink file that represents a contour curve of the original ink trace. A display module uses an algorithm to separate the contour curve into a sequence of straight lines. A set of pixels is then generated for the display of each straight line using a novel antialiasing method. The pixels at the ends of adjacent straight lines are aligned using a weighting algorithm.

Abstract: A system and process for determining the location of a captured image from a larger image is described. Using a list of determined locations, the system is able to determine the best or most likely path of a pen tip.

Abstract: A method and apparatus for determining a homography between an image and an expected image is described. The homography accounts for differences in perspective of a camera viewing an objective plane of the image, in some examples, a paper with information on it.

Abstract: Pre-processing techniques for processing an image to improve the distinctiveness of an information pattern captured in the image before the information pattern is analyzed in a decoding process. The brightness of an image first is normalized by dividing the image into blocks of areas, such as pixels. A brightness distribution value then is determined for each area of the image by fitting the brightness of its surrounding blocks using bilinear interpolation and extrapolation, and a normalized brightness value for each area can then be obtained by dividing the original brightness value by the brightness distribution value. Next, masks are created to distinguish the information pattern from content captured in the image. The masks may be generated based upon contrast differences between the brightness of pixels representing the information pattern, the brightness of pixels representing content, and the brightness of pixels representing the background of the writing medium.

Abstract: Methods and apparatus to lock a phase lock loop to a spindle motor are disclosed. An example controller comprises a counter to determine a period of an operating signal received from a motor, an oscillator to generate a control signal based on an input signal, and an initializer to generate the input value based on the period, wherein the input value causes the oscillator to generate the control signal having the same phase as the operating signal.

Abstract: Processes and apparatuses analyze an image of maze pattern in order to extract bits encoded in the maze pattern. Grid lines of a maze pattern are determined. Directions for effective pixels of associated bars are estimated and are grouped into clusters. Lines are estimated for selected effective pixels of a selected cluster that is associated with a first principal direction. Grid lines of another cluster are determined, where the other cluster is associated with a second principal direction that is perpendicular with the first principal direction. Estimated lines are pruned based on slope variation analysis, grouped based on a distance analysis, and a best fit line is selected from each group. Affine parameters are determined from best fit lines. The correct orientation of a maze pattern is obtained by determining a type of missing corner of the maze pattern. Bits are extracted from the image of maze pattern by processing gray level values of the associated maze pattern cells.