Abstract: A method for measuring the spatial frequency response (SFR) of an imaging system (299) including a display device (280) and an image capture device (290) is disclosed. The method displays a sequence of displayable test pattern images on the display device, the sequence comprising a first test pattern image and at least two subsequent test pattern images, each of the displayable test pattern images including a test pattern having at least one sinusoidal pattern at one or more spatial frequencies such that a phase shift of the sinusoidal pattern has a plurality of pre-determined values. The displayed images are captured with the image capture device to generate a corresponding sequence of captured test pattern images. The captured test pattern images are then compared with the displayable test pattern images to calculate the SFR at a plurality of image locations in the imaging system at the one or more spatial frequencies.

Abstract: A method for measuring the spatial frequency response (SFR) of an imaging system (299) including a display device (280) and an image capture device (290) is disclosed. The method displays a sequence of displayable test pattern images on the display device, the sequence comprising a first test pattern image and at least two subsequent test pattern images, each of the displayable test pattern images including a test pattern having at least one sinusoidal pattern at one or more spatial frequencies such that a phase shift of the sinusoidal pattern has a plurality of pre-determined values. The displayed images are captured with the image capture device to generate a corresponding sequence of captured test pattern images. The captured test pattern images are then compared with the displayable test pattern images to calculate the SFR at a plurality of image locations in the imaging system at the one or more spatial frequencies.

Abstract: A method (100) of demodulating a real two-dimensional pattern (110) is disclosed. The method (100) estimates (120, 130) a quadrature two-dimensional pattern from the real two-dimensional pattern (110) using a smooth phase only transform having an anti-symmetric phase, such as a spiral phase filter (140). A demodulated image is created by combining (180) the real two-dimensional pattern (110) and the estimated quadrature two-dimensional pattern.

Abstract: A method (400) of estimating an orientation angle (?0) of a pattern in an image (405) is described. A complex energy operator is applied to the image (405). The complex energy operator is defined as ?c{f}=(D{f})2?fD2{f}. A phase component of the result, which is defined as 2?0=arg(?c{f}) is determined, from which the orientation angle (?0) is calculated. A method (100,200) of demodulating a real two-dimensional pattern is also described. A two-dimensional spiral phase filter is applied to the pattern. The result is combined with the original pattern to provide a demodulated image. Furthermore, a method (600) of estimating a spatial phase of fringe pattern images in a sequence of fringe patterns is disclosed. The fringe pattern images are converted to pure AMFM patterns by removing offsets from each. Contingent analytic images are determined corresponding to each of said AMFM patterns, from which phase differences and phase shifts are determined from dependent pairs.

Abstract: Techniques for constructing a mosaic image from an MPEG video sequence. Constructing a mosaic image involves aligning and compositing the pictures of an MPEG compressed video. The described techniques use motion vectors in the MPEG video sequence directly to achieve picture-to-picture registration for each picture for which the MPEG video contains motion information.

Abstract: A method (400) of estimating an orientation angle (&bgr;0) of a pattern in an image (405) is described. A complex energy operator is applied to the image (405). The complex energy operator is defined as &PSgr;c{ƒ}=(D{ƒ})2−ƒD2{ƒ}. A phase component of the result, which is defined as 2&bgr;0=arg(&PSgr;c{ƒ}) is determined, from which the orientation angle (&bgr;0) is calculated. A method (100,200) of demodulating a real two-dimensional pattern is also described. A two-dimensional spiral phase filter is applied to the pattern. The result is combined with the original pattern to provide a demodulated image. Furthermore, a method (600) of estimating a spatial phase of fringe pattern images in a sequence of fringe patterns is disclosed. The fringe pattern images are converted to pure AMFM patterns by removing offsets from each.