45 results about "Spatial shift" patented technology

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 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.

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.

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.