45 results about "Spatial shift" patented technology

There is provided a method for detecting modulated light comprising: receiving a set of images acquired by means of a rolling shutter camera having image acquisition settings comprising a frame rate, fframe, and a line rate, fline; identifying in consecutive frames of said images—a pattern governed by the ratio between a modulation frequency, fc, of a modulated light source and the line rate, fline, and—between consecutive frames a spatial shift of said pattern governed by the ratio between said modulation frequency fc, and said frame rate, fframe; and providing based on said pattern and spatial shift thereof, an estimate of the modulated light amplitude from said light source.

A method and apparatus are disclosed for testing the accuracy of digital test images generated by a computer graphics program executed on a computer graphics system. A test program is utilized to compare a test image with a reference image. Regional image quantification verification aims at an image comparison test that accepts minor color value differences and spatial shifts in rendered pixel values. The test image and reference image are divided into corresponding sub-regions. The average color value for each sub-region of the test image is compared to the average color value of the corresponding reference image sub-region and also to other nearby reference image sub-regions. A test image is unacceptably different from a reference image, if for any sub-region of the test image, no reference image sub-region is found with an average color value difference and spatial shift less than specified maximums.

An image registration method is disclosed for processing a distorted image into a registered image that is aligned with reference to an original image. Distortions from the original image may include scaling, rotation, and noise. The method is based on correlating Radon transforms of both images to determine the rotation angle, and the scaling factor is determined by dividing averages of the overall luminance of each image on the assumption that any added noise will cancel. The Fast Fourier Transform (FFT) is used to estimate global spatial shifts. In one embodiment, the distorted image is first scaled to the size of the original image before being rotated. In another embodiment, the original image is first scaled to the size of the distorted image before rotating the distorted image, and finally scaling it to match the original image. A corresponding system for image registration is also provided.

A method and apparatus are disclosed for testing the accuracy of digital test images generated by a computer graphics program executed on a computer graphics system. A test program is utilized to compare a test image with a reference image. Regional image quantification verification aims at an image comparison test that accepts minor color value differences and spatial shifts in rendered pixel values. The test image and reference image are divided into corresponding sub-regions. The average color value for each sub-region of the test image is compared to the average color value of the corresponding reference image sub-region and also to other nearby reference image sub-regions. A test image is unacceptably different from a reference image, if for any sub-region of the test image, no reference image sub-region is found with an average color value difference and spatial shift less than specified maximums.

A method for providing a stabilized digital video sequence, comprising: analyzing a set of image frames captured at different times to determine one-dimensional image frame representations; combining the one-dimensional frame representations to form a two-dimensional spatiotemporal representation of the video sequence; identifying a set of trajectories corresponding to structures in the two-dimensional spatiotemporal representation; identify a set of foreground trajectory segments and a set of background trajectory segments; analyzing the background trajectory segments to estimate a motion pattern for the digital video camera; analyzing the motion pattern for the digital video camera to determine a undesired motion portion corresponding to an unintended camera shaking motion; applying spatial shifts to at least some of the image frames of the digital video sequence to provide a stabilized digital video sequence.

A method and apparatus are disclosed for testing the accuracy of digital images generated by a computer graphics program executed on a computer graphics system. A test program is utilized to compare test images with a set of reference images. Adaptive local image quantification verification aims at an image comparison that allows specified color value and spatial shifts. The color value for each pixel of a specified portion of the test image is compared to the average color value of an offset array of pixels in a reference image. A test image region may be unacceptably different from a reference image, if for any pixel of the test image region an offset reference image array is not found that has an array size, absolute color value difference, and spatial shift less than specified maximums.

There is provided volume holographic data recording media having a recording layer which is capable of recording interference fringes generated by interference of light having excellent coherence as fringes having different refractive indexes and undergoes holographic data recording by an amount of spatial shift distance of not more than 3 μm which is smaller than that of conventional media.

The invention discloses a diffractive optical imaging system wavefront inversion algorithm based on a phase difference method. The algorithm comprises the following steps: 1, a diffractive optical imaging feature characterization model containing the diffractive efficiency and the spatial shift characteristics of the diffractive optical imaging system is built; 2, based on a maximum likelihood method, a phase difference wavefront inversion model for the diffractive optical imaging system is built; 3, based on a scalar diffraction theory, a defocusing diffractive phase expression and a defocusing diffractive efficiency characterization model are deduced; 4, according to the spatial shift characteristics of the diffractive imaging, based on an isoplanatic region blocking idea, a focus surface space-variant degraded image and a defocus plane space-variant degraded image are subjected to blocking processing; and 5, a simulated annealing-based particle swarm algorithm is used to carry out global optimization solution on the phase difference wavefront inversion model, and the wavefront information corresponding to different view fields is outputted. A support is provided for the space application of a future super large aperture thin film diffractive optical imaging system.

The invention relates to a method for correcting possible spatial shifts in the excitation of measurement data. At least two measurement data sets are acquired, wherein the second or possibly each additional measurement data set is acquired while switching an additional gradient relative to acquisition of the first measurement data set. A phase difference for the respective measurement points of the measurement data sets is initially determined from the first measurement data set acquired without additional gradient and the respective corresponding data point in the at least one additional measurement data set acquired with additional gradients. A spatial shift of the measurement points of the first measurement data set acquired without additional gradients is determined from the determined phase differences. The magnitude values of the initially measured measurement points are distributed to their correct spatial position corresponding to the determined spatial shifts, whereby a corrected image data set is created. In addition, the present invention also provides a magnetic resonance apparatus, a computer program product and an electronic-readable data medium.

There is provided a method for detecting modulated light comprising: receiving a set of images acquired by means of a rolling shutter camera having image acquisition settings comprising a frame rate, fframe, and a line rate, fline; identifying in consecutive frames of said images—a pattern governed by the ratio between a modulation frequency, fc, of a modulated light source and the line rate, fline, and—between consecutive frames a spatial shift of said pattern governed by the ratio between said modulation frequency fc, and said frame rate, fframe; and providing based on said pattern and spatial shift thereof, an estimate of the modulated light amplitude from said light source.

A tunable dispersion compensator includes a collimating unit that collimates an incident light to output a parallel light, a parallel shifting unit that spatially shifts the parallel light from the collimating unit within a predetermined range, and an optical-path-length providing unit that provides optical path length of light corresponding to a position at which light output from the parallel shifting unit is input.

The invention discloses a grinding device with spatial displacement. The grinding device comprises a support frame. A spatial displacement mechanism is arranged on the support frame. A grinding head identification device is movably arranged on the spatial displacement mechanism. A clamping and adjusting mechanism for workpiece positioning is arranged below the grinding head identification device.The spatial displacement mechanism and the clamping and adjusting mechanism both are connected with a control system. The grinding device with spatial displacement adopts the frame type structure andhas the beneficial effects of being easy to manufacture, low in cost and stable and reliable; the arranged matched spatial displacement mechanism is simple in structure, high in moving precision and high in space flexibility and is suitable for multi-azimuth grinding operation; the grinding head identification device can accurately identify the position needing to be polished on the surface of a workpiece, the surface-repaired workpiece is identified and ground, the grinding efficiency is improved, and working hours are saved; and the clamping and adjusting mechanism can quickly adjust the position and the height of the workpiece, and the problems that the grinding workpiece is not easy to clamp and is easy to deflect when clamped are solved.

A method for deburring a gear blank includes correcting chamfer sizes, chamfer shapes and chamfer symmetry at tooth edges which were produced with a deburring cutter with a strongly asymmetric tooth shape (ChamferCut). The chamfers are semi-automatically corrected by coupling the movement of several axes of a gear cutting machine, including a workpiece axis of rotation C1, spatial shifting axes of a machine column Z1, X1, and Y1, and a V1-axis corresponding to the tool axis. The method further includes specifying a correction in the axial direction in one of the axes Z1, V1 and C1, and calculating the correction amount of further axes by the controller depending on the specified axis.

A visual quality assessment method and system are based on deriving a quality metric by comparing sub-band approximations of a distorted image and an undistorted version of the same image, providing a good compromise between computational complexity and accuracy. The sub-band approximations are derived from Discrete Wavelet (Haar) transforms of small image blocks of each image. Due to inherent symmetries, the wavelet transform is “blind” to certain types of distortions. But the accuracy of the method is enhanced, and the blindness of the transform is overcome, by computing quality metrics for the distorted image as well as computing quality metrics for a shifted version of the distorted image and combining the results.

A system and method involve receiving a sequence of images of an object with at least two consecutive images of the sequence being spatially shifted relative to each other. Each image is transformed into a Fourier domain using a Fourier transform to generate a corresponding plurality of Fourier transformed images. An amplitude filtered pattern is calculated in the Fourier domain based on amplitude components of the plurality of Fourier transformed images. Spatial shifts for pairs of consecutive images in the sequence of images are determined using the amplitude filtered pattern. Images in the sequence of images are aligned based on the determined spatial shifts and the aligned images are summed to form an image-shift-corrected summed image.

A method for deburring a gear blank includes correcting chamfer sizes, chamfer shapes and chamfer symmetry at tooth edges which were produced with a deburring cutter with a strongly asymmetric tooth shape (ChamferCut). The chamfers are semi-automatically corrected by coupling the movement of several axes of a gear cutting machine, including a workpiece axis of rotation C1, spatial shifting axes of a machine column Z1, X1, and Y1, and a V1-axis corresponding to the tool axis. The method further includes specifying a correction in the axial direction in one of the axes Z1, V1 and C1, and calculating the correction amount of further axes by the controller depending on the specified axis.

A holographic memory device is described which records and reproduces binary image data by irradiating a holographic recording medium with signal light and reference light. The holographic memory device includes a system for aligning polarization of the signal light and reference light on the holographic recording medium by guiding the signal light and the reference light to be coaxially opposed. The holographic memory device further includes a random-phase modulation multiplex recorder and spatial-shift multiplex recorder that, together with the system for aligning polarization, significantly enhances recording density and improves recording capacity.