A method and apparatus for precision distance measurement are provided to perform accurate measurement of distance to an object according to light spots formed on the light receiving surface of a detector even when multiple reflections are involved. A beam of light emitted from a light source and reflected from the object is focused on the viewing surface as light spots through an optical member. The focal position of a reflected beam of light is determined according to a focal position detection process. When there are peaks in a luminosity curve generated on the detector, prior to performing the focal position detection process, the peaks are separated into individual light spots and a correct light spot for deriving the precise distance is selected by a selection process.
A method of range imaging a scene includes directing a planar light beam onto a first portion of the scene, receiving a first reflected light stripe from that portion of the light beam on a row of sensors which emit responsive electrical signals. The first electrical signals are employed to create a salient feature containing saliency map with the salient feature being spatially related to the reflected light stripe. The light is subjected to sweeping to progressively create a plurality of light beams and reflected stripes leading to corresponding electrical output signals. This is repeated a plurality of times to establish the range image. In a preferred embodiment, a linear array of sensors has a winner-take-all circuit which selects a salient feature and employs that along with angle and time information to create an element of the image with repetition of the method generating the full range image. The light is preferably laser light and the sweeping action is preferably continuous through a plurality of cycles. Corresponding apparatus is provided.
A method of performing color space conversion and under color removal. Pixelated data is first resampled (102) to an efficient word size--typically 8-bits wide. The RGB color format data words are then subtracted from a maximum intensity to yield CMY color format data words. The minimum value of the three intensity words for each pixel is determined and used as an initial black value. A scaled version of the initial black value is then subtracted from each of the four CMYK intensity words (104). The resulting CMYK values are then limited to a range bounded by the maximum and minimum producible intensities for each color.
