Abstract: A noise prediction scheme provides a method of predicting an output noise variance resulting from a spatial filtering transformation. For a given input image signal with a known input noise variance, a periodic model is developed. The periodic model defines periodic boundary conditions for the input image signal based on the principal that the input image signal is repeated in each direction. In this manner, pixel values are defined about either side of the input image signal boundaries in either one, two, or three dimensions. A spatial filtering transformation includes convoluting the input image signal with an impulse response of a filter. Autocavariances at different points in time or lags of the input image signal are also determined. The number of autocovariances is determined by the nature of the spatial filtering transformation.

Abstract: In one embodiment, an apparatus for three-dimensional (3-D) image acquisition can include: (i) first and second lenses configured to receive light from a scene; (ii) first, second, third, and fourth sensors; (iii) a first beam splitter arranged proximate to the first lens, where the first beam splitter can provide a first split beam to the first sensor, and a second split beam to the second sensor; and (iv) a second beam splitter arranged proximate to the second lens, where the second beam splitter can provide a third split beam to the third sensor, and a fourth and split beam to the fourth sensor. For example, the sensors can include charge-coupled devices (CCDs) or CMOS sensors.

Abstract: Disclosed is a method for manufacturing thin sheets of high-strength titanium alloys. The method includes the steps of preparing initial blanks, assembling the initial blanks into a pack within a sheath, and heating and hot rolling the pack of the initial blanks in the sheath. The method is characterized in that, in the step of preparing the initial blanks, blanks having an (?-phase grain size of not more than 2 ?m are produced by hot rolling a forged or die-forged slab to a predetermined value of a relative thickness hB/hF, where hB is a thickness in mm of the initial blank before said pack hot rolling and hF is a final sheet thickness in mm, and by heat treating the initial blanks followed by rapidly cooling; and in that the step of pack hot rolling is conducted in quasi-isothermal conditions in longitudinal and transverse directions, while changing a rolling direction by about 90° after a predetermined total reduction in one direction is achieved.

Abstract: In one embodiment, a sub-pixel rendering method includes receiving 3D image data associated with pixel intensity values of N two-dimensional images having multiple sets of corresponding pixels. Each set of corresponding pixels includes N pixels (one pixel from each of N images) and each pixel has a green sub-pixel, a red sub-pixel and a blue sub-pixel. The method further includes mapping, for each selected set, N green sub-pixels, N red sub-pixels and N blue sub-pixels to M sub-pixels on a display to form a stereogram of the scene. The above mapping includes mapping N green sub-pixels from N images to N green sub-pixels on the display, mapping N red sub-pixels from N images to L red sub-pixels on the display, and mapping N blue sub-pixels from N images to K blue sub-pixels on the display, where L does not exceed N and K is lower than N.

Abstract: A system and method for efficiently performing a depth map recovery procedure includes an imaging device that is implemented in a single-lens stereo-shutter configuration for simultaneously capturing overlaid images corresponding to a photographic target. A depth map generator is configured to analyze the overlaid images to determine disparity values corresponding to separation distances between matching points in the overlaid images. The depth map generator then utilizes the disparity values to calculate depth values that correspond to locations in the photographic target. The depth map generator may then utilize the foregoing depth values for creating a depth map corresponding to the photographic target.

Abstract: The present invention concerns the blending of plural x-ray images to form a blended composite image wherein in blending the images, a stitching boundary adjustment is determined for use in adjusting boundary pixels of the composite image, and an adjustment for other pixels that are located at some distance from the boundary is determined, wherein the adjustment for the other pixels depends on the stitching boundary adjustment and on values of the boundary pixels.

Abstract: A three-dimensional (3D) acquisition and visualization system for personal electronic devices comprises two digital cameras which function in a variety of ways. The two digital cameras acquire 3D data which is then displayed on an auto-stereoscopic display. For clarity and ease of use, the two digital cameras also function as eye-tracking devices helping to project the proper image at the correct angle to the user. The two digital cameras also function to aid in autofocusing at the correct depth. Each personal electronic device is also able to store, transmit and display the acquired 3D data.

Abstract: A system, method, and computer-readable medium for detecting and eliminating correspondence errors associated with image occlusions. In a first embodiment of the invention, the method applies traditional correspondence methods for matching points in two images, a left image (FIG. 1A) and a right image (FIG. 1B), taken of the same scene. The method applies the correspondence method to locate a matching a point (310) in the right image (FIG. 1B) with a “best match” point (320) in the left image (FIG. 1A). A set of matching points (310, 320) is generated. A second search is then performed by using the best match point (320) in the right image (FIG. 1B) as the basis for an additional correspondence search in the left image (FIG. 1A). The range of match candidates in the second search is such that points to the left of the starting point (310) are not tested as match candidates.

Abstract: Pairs of stereo Xray radiographs are obtained from an X-ray imaging system and are digitized to form corresponding pairs of stereo images (602, 604). The pairs of stereo images (602, 604) are adjusted (410) to compensate for gray-scale illumination differences by grouping and processing pixel groups in each pair of images. Distortion in the nature of depth plane curvature and Keystone distortion due to the toed-in configuration of the X-ray imaging system are eliminated (412). A screen parallax for the pair of stereo images is adjusted (414) to minimize depth range so as to enable a maximum number of users to view the stereoscopic image, and particular features of interest.

Abstract: A computer-implemented method and system for equalizing the brightness, contrast and color of two or more images (206, 208) of an eye fundus (106). Because left and right images (206, 208) are taken from different camera (104) positions, or because two images (206, 208) have been taken at different times, the resulting images (206, 208) have different brightness, contrast and color. Groups (306, 308) are formed from the pixels making up the images (206, 208). The groups can be straight lines oriented perpendicularly to the direction of camera (104) motion. The intensity of each pixel in a group is measured, and the group's mean and variance are then calculated. The intensity of the groups are then adjusted in order that a group (306) from the left image (206) will have the same mean intensity and variance as the corresponding group (308) from the right image (208). The measurements and adjustments can be made for each of the red, green and blue intensities of each pixel.

Abstract: A digital radiographic system in which a digital detector captures digital radiographic image data based on exposure of a patient to x-ray energy from an x-ray source, and assesses the acceptability of the digital radiographic image data at a time before the radiographic protocol has otherwise ended. Additionally, the digital radiographic system signals whether the digital radiographic image data is unacceptable based on the assessment, and allows for the initiation of a retake. The assessment may be made based on acceptability of the exposure and/or based on the acceptability of motion artifacts in the image. If the image is unacceptable, the technologist is alerted that a re-image is needed, with the alert being made in real-time immediately after the image is captured.

Abstract: A radiographic imaging system (100) comprises an X-ray tube (110), a sensor plate (120), and a graphics engine (130). The tube (110) and the sensor plate (120) rotate synchronously about a patient (150) and expose a stereoscopic pair of images which are transmitted to the graphics engine (130). The graphics engine (130) determines (312) the geometry of the system (100). If (314) the pair of images are toed-in relative to each other, the graphics engine (130) converts (316) the images into a parallel geometry. Likewise, the graphics engine (130) also processes (320) the images for keystone distortion, if necessary. Simply flipping the images in the stereo pair distorts the depth of objects in the stereoscopic image. Instead of simply flipping the images, it is desirable to “go behind” the screen (412A) and look at the image from the back.

Abstract: Automated computer aided diagnosis (CAD) processing of digital radiographs through model-based interpretation, with the initialization providing a set of initial parameters used by the model. The initial parameters can be selected based on expected pathology in the digital radiograph, and are optimized by the model to match features shown in the radiograph. The model can be an iterative model or a non-iterative model. Analysis is performed on the interpretation result, so as to diagnose pathology shown in the radiograph.

Abstract: A method (500) adjusts the epipolar lines associated with two or more images (110,120) taken of the same scene such that the images (110,120) are and vertically aligned. The method (500) creates two or more search columns on the first image. The images (110,120) are split into grayscale sub-images corresponding to each color coordinate used to describe the color of a point in the image. A matching algorithm is applied to each point in the search column in each sub-image pair to calculate the vertical shift between the matched points. The shift values calculated for the matched points are then extrapolated across the entire image and used to align the points in the first (110) and second (120) image.

Abstract: One or more fiducial marker projections are located in a radiographic image, where the radiographic image is stored as digital image data. The digital image data is filtered with a grayscale morphological filter to enhance potential fiducial marker projections. The filtered digital image data is segmented into one or more seed regions, where each of the one or more seed regions contains a potential fiducial marker projection. The potential fiducial marker projection within each of the one or more seed regions is analyzed and verified and a location of a fiducial marker projection within the radiographic image is determined for each verified potential fiducial marker projection.

Abstract: A method locates one or more physical pointers around the body, such as a steel ball or other distinguishable item, and captures two distinct x-ray images (410) of the body, such that the physical pointers are captured in the x-ray images. The locations of the physical pointers in the images (410) are used to estimate the horizontal and vertical distortions. The images (410) are adjusted vertically and horizontally to correct for any estimated distortions. A disparity map may then be calculated manually or using the classic epipolar stereo matching technique. The disparity map provides the location of one or more distinctive objects inside the body.

Abstract: A system, method, and computer-readable medium for capturing radiographic images and processing the captured images into stereo images. The images are captured using an X-ray imaging system that rotates freely about an anchor point and captures images of the patient or other object from different angles. The images are transmitted to a graphics engine (130) that rotates and adjusts points in the images in order to place them in the same plane and may also combines the two images into a single stereo image. Additional error processing methods are provided in order to reduce resulting distortion.

Abstract: Enables the dynamic mapping of color vectors to numeric data. Values or value ranges split a data set stored in a matrix into intervals. The intervals are assigned corresponding color vectors that are used to define the color vector calculated for each of the data points that fall within the intervals. The intervals also serve to filter out unwanted information from the matrix. The function used to calculate the color vectors assigned to the data points may also vary based on the type of data being analyzed. The color vectors calculated for the data points are stored in a color matrix and the vectors may be further mapped to an image file in accordance with provided mapping information.

Abstract: A stereo radiograph is produced in a radiography system including an anti-scatter grid (105) and sensor material (107). At least one x-ray beam (102) is emitted towards a body to be radiographed (103). The anti-scatter grid (105) is focused so as to transmit two distinct x-ray beams (106) to the sensor material (107). The transmitted beams (106) create two alternating images on the sensor material (107). A stereo radiograph is created from the two alternating images. System geometry of the radiography system is used to determine location of an object (606) within a radiographed body (103), and to determine distance (613) between a chosen point and an object (606) within a radiographed body (103).