Abstract: An interpolation circuit multiplexes inputs prior to one or more additions during an interpolation operation, thereby reducing the number of components implementing the interpolation circuit. The multiplexers apply shifted inputs to adders in a sequence that produces the desired binary based interpolated values. The interpolation circuit can be used to programmably produce filter coefficients.

Abstract: A character segmentation process for skewed documents divides the document bit map into vertical blocks and within each vertical block estimates initial top and bottom bounds of each character in a character row from horizontal projections of the vertical block, thereby avoiding the effects of skew. Operations in the document bit map to compute the exact top, bottom, left and right boundaries of the character are confined within the narrow strip between the initial top and bottom bounds of the character so as to greatly reduce the amount of data fetched from memory during such operations and thereby speed up the segmentation process.

Abstract: In accordance with the present invention, the R,G,B color image signals from a single sensor having a color filter array are all transformed to .GAMMA.-space by changing them to R.sup.1/.GAMMA., G.sup.1/.GAMMA., B.sup.1/.GAMMA., respectively, where .GAMMA. is approximately 2.4. In this space, all operations such as color differencing, interpolation of those missing pixels required for color differencing, compression, decompression, edge enhancement and final interpolation of all missing pixels are performed without further transformation of the image signals. For the same final bit rate, noise in the reproduced image is reduced by refraining from interpolating the missing color pixels prior to compression of the image data.

Abstract: The invention is a high speed error diffusion process consisting of repetitive computational cycles in which a binary print value is determined from an error-diffused pixel in a continuous tone image. In each cycle, the computation of the previous pixel error exploits computations made during the previous cycle. Specifically, for a continuous tone image consisting of n-bit pixels, the n least significant bits of the previous pixel error are computed during the previous cycle and its sign bit is determined during the current cycle. The n least significant bits of the previous pixel error are the n least significant bits of the error-diffused pixel of the previous cycle. The sign bit of the previous pixel error is determined during the current cycle from the three most significant bits of the error-diffused pixel value of the previous cycle and from the binary print value of the previous cycle.

Abstract: A contrast autofocus mechanism for a still camera automatically controls the displacement of an imaging lens (10) so as to cause an image of a subject (32) to be quickly brought into focus upon the len's image-receiving plane (24) in response to successive contrast measurements taken at different conditions which produce different depths of field. The change in depth of field may be accomplished by changing the aperture setting for successive contrast measurements. Based upon difference in contrast for the two measurements, the extent to which the lens is out-of-focus is calculated. This calculation is used to define the displacement of the lens to a new position which should be at or nearly at a position of peak contrast. If at the new position further refinement is necessary, a trial and error subroutine is conducted to determine in which direction the lens should be moved to attain focus.

Abstract: The multiplexing character processor of the present invention multiplexes data characters to and from a plurality of communication lines to a Central Processing Unit by bit slicing. Input data present on the plurality of communication lines is sampled at a rate which is at least 16 times the data bit rate and is formulated as a serial data bit stream. Each sample corresponds to a time slice which slice is allocated to a given communication line under the control of a scan list. A high data rate communication line can be placed on the scan list more than once to insure accurate data reproduction. Character assembly and disassembly is performed in an arithmetic logic unit (ALU) under program control, to provide the flexibility to support various communication link protocols. The input data on each communication line may have a different protocol. Synchronization of the serial data bits to the communication lines is performed by a data bit synchronizer DBS.

Abstract: A plurality of color photographic images that have been captured on a continuous color photographic film strip are pre-scanned at low resolution and then rescanned at high resolutin by an opto-electronic scanning device and processed for storage as a plurality of digitized images in a digital imagery data base. The film strip contains notches to spatially locate pre-scan frame data during rescan. During pre-scan the film strip is translated past an opto-electronic scanner in a first direction to obtain a plurality of first digitally encoded images. During high resolution rescan, the film strip is translated in the reverse direction. The high resolution imagery data is mapped into image storage memory on the basis of the contents of respective first digitally encoded images.

Abstract: A first embodiment of the present invention provides logic to select between one of three or more user entered video standards and one or more selectable default video standards. The logic overrides the default standard with the user selected standard. A second embodiment includes a state machine that sets a mode output to a default standard from among two or more standards specified at the factory using jumper pins. The state machine can step through the two or more available standard modes, thereby changing the picture displayed to the user and, as desired, allowing the user to indicate what standard should be used.

Abstract: A multipurpose interface circuit through which the control current for operating an electromagnetically driven shutter actuator for applications such as a still camera may be precisely defined throughout a shutter actuation sequence (open, hold and close) has a clock signal counter unit, which contains a set of counter circuits associated with respective components of the shutter actuator drive current waveform. The counter circuits are sequentially enabled to count clock signals generated by a clock signal generator. The counter circuits produce output signals in accordance with a set of relationships among the numbers of clock signals counted and a set of shutter control codes representative of desired shutter aperture size and shutter speed. A control circuit is coupled to the clock signal counter unit for controlling the generation of the respective components of the actuator drive current in accordance with output signals produced by the clock signal counter circuit.

Abstract: An edge detection mechanism for an imagery signal compression and transmission system processes histogram and variance data to identify the presence of a uniform area with a block of transform signals. The presence of an edge within an image block, for which corresponding transform coefficients are obtained, is identified by initially generating a histogram of the image block. If the maximum value of the histogram exceeds a first threshold value, a uniform area is inferred, and adaptive quantization that would otherwise be carried out prior to executing a minimum redundancy encoding scheme is bypassed. If the maximum value of the histogram does not exceed the first threshold value, a set of variance calculations is carried out for use with a further sequence of edge detection decisions. The total variance and low frequency variance of the block are determined in accordance with the transform coefficients associated with the image block.

Abstract: A digitized image previewer framestore apparatus enables a photofinisher to rapidly view what is seen by a high resolution CCD image sensor (but at a lower resolution) on a preview display. A selected portion or selected portions of the imagery data derived by way of the array of pixel elements of the high resolution sensor are controllably coupled to a pair of `ping-pong` write/read memories. The image resolution or storage capacity of each of memory is less than that of the high resolution CCD sensor and is considerably less than that of the 3072.times.2048 resolution of a high resolution color output image to be stored on compact disc. Depending upon the selected portion of the image incident on the CCD sensor is to be viewed, respective pixel and line rate clocks for the CCD sensor are subsampled and coupled to address generating counters used to access the ping-pong memories. As a result, only those CCD pixels for which (subsampled) clock signals have been generated will be displayed.

Abstract: An encoder and a decoder is provided with each being usable independently of each other for improving the dynamic range of clipped speech digital systems by providing amplitude components to the clipped digital signal. The encoder processes an audio input signal along two signal paths, the first signal path including a clipper and digitizer means for forming a digitized clipped signal. The second signal path includes a rectifier, envelope detector and digitizing means for forming a digitized signal having amplitude components. Both digitized signals may then be transmitted to the decoder for reconstruction or stored for reconstruction at a later time.

Abstract: This invention relates to a method for increasing the range of values representing a color image which exhibit a linear response. To increase the linear range, look-up tables are formed which straighten the toe and shoulder regions of film's three density vs log exposure curves up to a prescribed limit. The values of the minimum densities for the piece of film containing the image are determined. The representative values of the image are then aligned with the input values of the look-up tables by a relative shift of the image values and the table values so that the minimum density values of the image equal the minimum density values in the look-up tables. The color density image is then processed through the look-up tables to increase its linear range.

Abstract: A mechanism for recoloring a color image defines a spatial region within the image (such as the pupil of the eye) a color characteristic of which (e.g. the `red-eye` phenomenon) is to be selectively modified. To determine whether the color of an image sample within a spatial region is to be modified, the value of the chrominance component of each sample within the region is compared with a regularly shaped (e.g. elliptical) chrominance variation discriminator that surrounds a target color of interest (e.g. red, in the case of a `red-eye` correction). The major axis of the ellipse coincides with the saturation direction of the chrominance plane and its minor axis coincides with the hue direction. For each sampling location within the spatial region, the value of the chrominance component is examined to determine whether it falls within the elliptical chrominance discriminator.

Abstract: The present invention is an all digital timing and address generator which automatically adjusts its output pulse intervals to fit within the duration of periodic input pulses. The intervals are alway synchronous with the leading edges of the input pulses, and their number within the duration of a periodic input pulse is selectable in increments of one. The generator uses direct digital feedback to control its output timing for changes in input pulse width, and employs an integer time mark to prevent "unlocking" on non-integer width input pulses.

Abstract: A first inverter circuit is coupled between a first voltage source and a reference potential by a plurality of cascaded transistors. Each of the cascaded transistors has a control gate which may be selected to bring the resistance of the transistor into circuit with the inverter circuit to control the charging rate of a distributed capacitance. An output circuit coupled to the first inverter circuit provides the distributed capacitance and an inverted buffered output. The output circuit also includes an output which may be connected to another circuit of the present invention to form a cascaded delay circuit and to receive a reset signal for resetting the cascaded delay circuit.

Abstract: A radiation image reading apparatus using a storage phosphor plate as a radiation image record is disclosd which includes a light beam scanning device, detection device and control device. The light beam scanning device generates a laser beam and scans the phosphor plate with the laser beam. The detection device detects a phosphor light from the phosphor plate generated by the irradiation of the laser beam and outputs an electrical image signal corresponding to the image information recorded at each of the pixels of the plate. The control device includes an optical shutter which is controlled so that the light beam from the scanning device is provided to generate only one beam spot for each of the pixels of the plate.

Abstract: The present invention is a system that includes a quadrant detector with an axis between the detector elements aligned with the direction of film motion. The output of the detector is used by an analog signal processor composed of adders and subtractors to produce signals for detecting the center of the perforation and lateral displacement of the perforation and to provide an illumination adjustment signal. Control logic connected to the analog processor produces signals indicating perforation edge crossings. The center crossing signal is used to control sampling of an illumination adjustment signal and a lateral displacement signal while the edge crossing signals are used for a timing reference for the bottom edge of the film frame. The control logic also detects these trigger signals, controls the capture of the illumination and displacement signals and provides an interrupt to a computer to indicate the capture operation is complete.

Abstract: A camera having highlighting for the subject of the photograph and detection of motion of the subject. The camera detects the scene electronically and digitally stores the scene in memory. A gradient operation is performed on elements in the image to produce an indication of the outline of the subjects witin the depth of field. This outline may then be used to highlight the subjects in the viewfinder using an LCD as a mask. The outline may also be used to determine any movement of the subject in order to prevent blur or used as a trigger in a burst exposure mode.

Abstract: A stereoscopic electronic viewer for a stereo image pair provided in a fixed medium includes a light source which passes light rays through the fixed images of the stereo image pair. The rays project onto a mirror which redirects the rays through a lens unit. The light rays from each image are associated with a particular lens in the lens unit which focuses the image onto an associated CCD image sensor. The two CCD image sensors have separate but synchronized electronics and provide a synchronized output which is fed to a stereo viewing device such as stereo goggles or a time-multiplexed polarized display. The electronic viewer is mechanically designed to manipulate the image produced on the display device to allow for panning and zooming of the stereoscopic image while maintaining the full resolution provided by the image sensor.