Abstract: In the past, databases containing three dimensional images were searched by keywords and indexes. For such functionality a set of keywords must be associated with each image. This is not a dynamic method and is prone to errors. It has been found that searching of three-dimensional images stored electronically can be performed in dependence upon characteristics of the image such as colour, shape, size, scale, etc. A method is disclosed for searching three dimensional images in dependence upon image characteristics.

Abstract: The present invention provides a method and an apparatus for detecting a position of a light spot in a light distribution that can include stray light components (e.g. from other lasers, ambient lighting etc.) The apparatus includes a continous response position sensitive detector (CRPSD, e.g. lateral effect photo-iode) for determining a first centroid of the light distribution and a discrete response position sensitive detector (DRPSD, e.g. multiplexed array) for determining a second centroid of the light distribution within a reading window defined about the first centroid and within the light distribution. The second centroid represents the position of the light spot in the light distribution. This multiple stage approach exploits the high resolution and speed offered by traditional CRPSDs together with the accuracy under variable lighting conditions offered by traditional DRPSDs.

Abstract: Simulating a photographic camera for rendering two-dimensional images of virtual three-dimensional objects enhances flexibility and ease of use of a rendering system. Simulating a photographic camera is performed by determining light from virtual light sources that passes through a lens of the simulated photographic camera having an aperture, focus, and shutter speed and is incident upon the imaging plane within the camera. The method also has application in teaching photography because, in some instances, computer simulation reduces the cost of equipment and consumables.

Abstract: Faces are one of the most commonly recognized features among people. According to the invention a system for recognizing intensity images of faces is provided. Intensity images of a face are captured and normalized. The intensity images are transformed, filtered and then transformed again. The filter is based on a three-dimensional image of a face against which the intensity image is being compared. The result is a form of correlation that is substantially illumination independent.

Abstract: In the past, databases containing three dimensional images were searched by keywords and indexes. For such functionality, a set of keywords must be associated with each image. This is usually performed by a person and is prone to errors. It has now been found that searching of three-dimensional images stored electronically can be performed in dependence upon a variety of criteria such as colour, shape, size, etc. A method is disclosed for searching three dimensional images of objects in dependence upon the above criteria, other images, or other criteria. This obviates the need for keyword indexing of image databases.

Abstract: A three dimensional imaging method and device including a ranging sensor that is used to produce a series of profiles of a target surface. The profiles comprise one set of profiles nearly parallel to each other and a further such set of nearly parallel profiles, with the profiles of one set extending at an angle to those of the other set to generate a large number of profile crossings. At the location of each crossing the shortest distance between the profiles is detected and represents an energy contribution between this pair of profiles. An energy function is defined as the sum of the energy contributions of all the crossings. Using a known mathematical model, the profiles are then reoriented relative to each other in such a manner as to minimise this total energy. This process can be repeated for higher precision. The finally reoriented profiles can be used to define the desired three-dimensional shape of the target surface.

Abstract: An optical method and apparatus is provided for determining the color and profile of a target surface of an object. The target surface is scanned with an incident beam of light containing a plurality of wavelengths including at least one well defined wavelength. A return beam reflected from the target is split into at a first and second return beam. The first return beam is utilized for detecting the profile of the target surface; and, a plurality of detectors are provided that detect color information corresponding to the target surface from the second return beam.

Abstract: A method and apparatus is provided that lessens the unwanted effects of noise present at the input of an imaging system. By tapping a small portion of a laser input signal containing wavelengths of light corresponding to red, blue, and green of light used to scan the surface to be imaged, the tapped signal is used to generate three beams that correspond to the red, blue, and green content of the laser input signal. Signals generated at the output of the system that correspond to the color of the scanned surface are normalized with the signals that correspond to the three beams generated by the tapped signal. The normalized output signal indicative of the color of the surface is noise reduced; substantially most of any noise present at the input is eliminated from the output of the device.

Abstract: Three dimensional digital imaging of the profile of a surface of an object is improved to include the collection of data on the color of the surface, this result being achieved with only minor changes to a monochromatic 3-D camera and without the complications of multiple detectors or multiple color filters. The surface is scanned with an incident beam of light that contains a plurality of wavelengths including at least one well defined wavelength, e.g. either three well defined wavelengths corresponding respectively to the primary colors, or a continuum of visible light plus one well defined wavelength outside such continuum. The return beam that is analyzed to generate the digital profile data is dispersed into a plurality of separate return beams according to wavelength, the relative intensities of such separate return beams providing the color data.

Abstract: A three dimensional imaging device has a converging lens system defining an optical axis, known as the Z direction. The imaging device also includes a position sensitive detector that has a series of pixels extending in at least a selected one of two mutually perpendicular X and Y directions both perpendicular to the Z direction. The lens system will simultaneously image a plurality of distributed points on a target surface onto the detector to generate first data on the coordinate of each point on the target surface in the X and/or Y direction. Also included in the system is a mask having a pair of apertures spaced apart from each other in the selected direction and respectively aligned with portions of the lens system for imaging discrete dots on the detector. The spacing between the dots generates second data on the coordinate of each point on the target surface in the Z direction.

Abstract: A three dimensional imaging device has a converging lens system defining an optical axis extending in a direction Z, and a color sensitive position sensitive detector having a series of pixels extending in at least one of two mutually perpendicular directions X and Y both perpendicular to the direction Z. The lens system serves to simultaneously image a plurality of distributed points on a target surface onto the detector to generate first data on the coordinate of each point in at least a selected one, and preferably both, of the directions X and Y. A mask with a pair of differently colored filters, e.g. red and blue, spaced apart from each other in the selected direction is mounted in the lens system for forming a pair of discrete images on the detector of each point, such images being formed each in a respective color. The result is to generate, by means of measurement of the spacing between the images, second data on the coordinate of each point in the direction Z.

Abstract: A triangular, synchronous optical scanning apparatus to be used in a three-dimensional imaging is disclosed. A pair of curved stationary reflecting mirrors can be provided in optical beam paths to modify the reference plane to conform to the target surface.

Abstract: An imaging device employs a known bidimensional, position sensitive light detector of the CCD type. A converging lens system images points on a target surface onto the detector to generate data on the X and Y coordinates of each point. The invention is characterized by a mask located in the aperture plane of the lens system. This mask either has a pair of spaced apart, separate, circular apertures or an annular aperture symmetrical about the optical axis. In the first instance, the result is to form spaced-apart dots on the detector for each point of the target surface, the distance between these dots being a measure of the Z coordinate of the respective point. When using the annular aperture, rings are formed on the detector, the ring diameter representing the Z data. The arrangement provides a compact and robust device for obtaining three dimensional data on a target surface.

Abstract: A three dimensional imaging system operating in accordance with the known active triangulation method employs a laser beam that is projected onto an area of a surface the profile of which is to be examined. A beam reflected from such area is received in a position sensitive detector. With synchronised scanning of the projected and detected beams by a system of mirrors, the detected position in the detector remains unchanged when the surface under examination is a flat reference plane, changing only as a measure of the degree of deviation of each examined area from such reference plane in a direction Z. The system is characterised by this basic scanning being carried out in such a way that the beams are scanned in a direction X lying in the beam plane, i.e. the plane defined by the beams, and by a further simultaneous and synchronous scanning that takes place in a direction Y. The directions X, Y and Z are all mutually perpendicular.

Abstract: The apparatus generates two optical beams which are directed to a relatively moving solid surface where an interference pattern, having substantially parallel fringes, is formed. The light is scattered and thereby modulated by irregularities on the surface. This modulated light is received and the signal is processed to indicate the length of the surface or its relative speed. The signal processor converts the modulated light signal to a pulse train, and adds pulses to the pulse train when a drop-out in the signal is detected, i.e. when the time between pulses in the pulse train is greater than a factor times the average period of the pulse train. The corrected pulse train is a function of the length of the surface or the relative motion between the apparatus and the surface.