Abstract: Among other things, a texture of an image is characterized by deriving lacunarity measures from the image based on a wavelet analysis.

Abstract: A compact wavelength division demultiplexer device comprises two cascaded interferometers the wedge angle of whose mirrors are orthogonal to each other, i.e., the two interferometers are oriented such that the dispersion of light with wavelength from the second interferometer is orthogonal to the dispersion of light with wavelength from the first interferometer. The incoming beam of laser light carrying n sub-bands of m information channels is collimated and applied to the first interferometer whose free spectral range is determined by the total bandwidth required by the n×m channels and whose finesse is determined by the resolution needed to spatially separate each of the n sub-bands from one another. The light leaving the first interferometer enters the second interferometer whose wedge angle is at 90 degrees to the plane of the wedge angle of the first interferometer.

Abstract: Systems and methods for the multispectral imaging of skin tissue enables automatic characterization of the condition of a region of interest of the skin, based on direct digital imaging of the region of interest or the digitization of color photographic slides of the region of interest, illuminated by appropriately filtered light. Preferably, a digital image at a low spectral band is automatically segmented and that segmented mask is used to segment the other images by a digital processor. Parameters related to the texture, asymmetry, blotchiness and border irregularities are also automatically estimated. The region of interest is automatically characterized by the digital processor, based on those parameters. The region of interest may include a skin lesion, in which case the present invention enables the characterization of the lesion as malignant or benign.

Abstract: Common path, two beam interferometers and interferometric measurement systems employ a voltage controlled variable phase retarder enabling rapid stepping of the relative phase between two interfering optical beams by suitable control of the voltage. The beams need not be laterally separated. A compact beam expander with a ball lens is preferably included. The system is compact enough to be contained in a hand-held unit. The system can be used for surface mapping, testing of optical components and detecting the motion of mechanical objects, for example. It is particularly well suited for the mapping of the skin of a live subject. An optimum fringe period and optimum illumination wavelengths for imaging skin are disclosed, enabling the topography of substantial areas of human skin to be rapidly and accurately measured, in times on the order of one-tenth of a second. Methods of conducting interferometric analysis are disclosed, as well.

Abstract: The invention consists of a method of redirecting light to improve the transmission efficiency of wedged multibeam interferometers, either individually or in cascade with other interferometers. Optical fibers are placed to direct reflected light into such positions which enable iterated transmission of this otherwise wasted light through the interferometer. The increased light coupling efficiency provided by the method makes it well suited for applications to fiber optic communication links, fiber optic Bragg sensors, ladars and lidars.