Abstract: A video decoder decodes a video signal based on a down conversion function. The video decoder includes a variable length decoder which analyzes a received compressed video stream and extracts motion signals. The analyzed bitstream is converted into a macro block through an inverse quantizer and inverse discrete cosine transform unit in succession, and a motion compensator compensates up-sampled data using the extracted motion signals. Data from the IDCT and data from the motion compensator are added, down-sampled by an adaptive down sampler, and stored in an external memory. For motion compensation, the adaptive up-sampler up samples the data down-sampled at the adaptive down sampler, and the result is provided to the motion compensator.

Abstract: A picture coding apparatus has a signal processor 10 for generating macro-block information by calculating and quantizing the DCTs of a picture signal of a given unit are calculated for each macro-block MB. This information is input to a syntax generator 12 to generate syntax, which is coded by a variable-length coding processor 13. Quantized DCT coefficients of macro information before coding are counted by a count unit 21, and a code size after coding the macro-block information is counted by a count unit 14. A calculation unit 15 calculates an average code length from the accumulated value of the two code sizes. An estimation unit 14 estimates a generation code size after coding given macro-block information input to the syntax generator 12 on the basis of the average code size.

Abstract: A data storage and reduction method for digital images having a chronological order involves storing a first and chronologically new image or group of images at a first image quality requiring a first amount of storage space, and processing a second image or group of images, chronologically older than said first image or group of images, by reducing the image quality thereof to a second image quality requiring a second amount of storage space, which is less than said first amount of storage space. Advantageously, the method is used for a surveillance system, comprising a camera, a digital storage device and an image storage controller, wherein image quality is reduced for old or otherwise less important images or groups of images, thereby obtaining additional storage space for allowing more important images (such as images relating to an alarm event) to be stored at higher image quality, while retaining an extended total recording time span.

Abstract: A marine plant field survey method includes the step of using a submarine mobile video system capable of taking images underwater to measure degree of macrophyte coverage in a marine plant field by taking wide-field images of macrophytes from above and a step of using the submarine mobile video system to discriminate species of macrophytes by taking images of macrophytes from a direction other than from above. A marine plant survey system includes a camera for taking wide-field images of macrophytes from above and a camera for taking images of macrophytes from a direction other than from above.

Abstract: A variable bitrate coding method includes an iterative process including a first analysis pass and a second prediction pass. Further, followed by a last control step for adjusting a stepsize with respect to a target bitrate. A picture re-arrangement step is also provided between the analysis and prediction steps of one iteration, in order to encode with an improved quality the picture sequence. This coding method is applicable to MPEG-2 encoders for storage media with limited capacity.

Abstract: A motion vector coding method is provided. The motion vector coding method includes the steps of (a) performing an affine motion estimation to obtain affine motion parameters, (b) converting the affine motion parameters to a predetermined number of translational motion vectors, and (c) coding the difference between the converted translational motion vectors of a current block and the converted translational motion vectors of a previous block. The method allows for low bit generation while maintaining motion estimation performance available from affine motion estimation.

Abstract: A system and corresponding method for adjusting the brightness and color of MPEG encoded video images. A digital versatile disk player capable of decoding a previously encoded MPEG video signal and adjusting the brightness and color of the entire previously encoded MPEG video signal based on a subset of information contained in the encoded input signal. The brightness and color adjustments are performed while the encoded MPEG video signal is in the frequency (dct) domain before motion compensation is performed. The digital versatile disk player also determines whether the particular block to be decoded is of a predetermined type and decodes such block accordingly.

Abstract: An oral cavity image pickup apparatus having an image pickup device and a holding device including a first arm and a second arm. The first arm is of sufficient length for placement inside an oral cavity at least between left and right molars defining a transverse dimension. The image pickup device has an object lens and an imaging device and is held on at least the first arm between the first and second molars. The second arm has a first part for placement inside the oral cavity and coupled to the first arm. The second arm also has a second part at least as wide in transverse dimension as the first part for extending from both sides of the oral cavity. The image pickup device can image pick up full or partial dentition exposed inside and/or outside the oral cavity and partial bio-tissue at the same time.

Abstract: A key frame representative of a sequence of frames in a video file is selected. The sequence of frames is divided into shots, sequences of frames captured by a single continuous operation of the camera, by detecting shot boundaries. Shot boundaries are detected by measuring changes in motion activity between frames using measures of pixel intensity and histogram differences between frames. The most interesting shot in the sequence of frames is selected using measures of motion activity, spatial activity, skin pixel color and shot length. The key frame is selected in the most interesting shot using measures of spatial activity and motion activity.

Abstract: A motion compensation improvement for a compression encoder minimizes redundant edge information in a current image from a video input signal being input to the compression encoder. The current image is compared with a reference image from the video signal, which images may be the entire picture or a sub-region of the picture, to provide a spatial shift difference between the images, the spatial shift difference having an integer part and a high precision fractional part. From the high precision fractional part and specified constants for the compression encoder a shift value is calculated such that, when shifted, the current image is aligned with a quantizer motion vector grid in the compression encoder. The shift value is then used to resample the current image to make the desired shift prior to input to the compression encoder, thereby minimizing redundant edge information.

Abstract: A video decoder for decoding data at a high rate uses a plurality of slower slice decoders. A common memory is shared by all slice decoders drastically reducing storage requirements of individual decoders. Slices are allocated to decoders optimally in response to busy signals providing improved performance over known methods. HDTV signals are decoded using a plurality of ordinary television resolution decoders. Multiple data streams are also decoded.

Abstract: Methods and apparatus are provided for selecting a cut-off index to filter transform coefficients associated with an input bitstream to provide filtered transform coefficients associated with a rescaled output bitstream. An arrangement of transform coefficients associated with an input data sequence (e.g. an audio segment or a video image block) is filtered using a cut-off index to provide modified transform coefficients associated with a modified output data sequence. Information including information about the input data sequence and the modified output data sequence can be used to update the filter cut-off index for reduction of future data sequences.

Abstract: System and method for generating video frames. The system includes a frame generator which generates one or more intermediate frames based upon one base frames. Each of the base frames are comprised of a plurality of macroblocks. Furthermore, one or more of the macroblocks have a motion vector. The macroblocks are comprised of a plurality of pixels. In the frame generation process, the frame generator performs a number of steps such as: (i) determines whether frame generation is appropriate, (ii) examines the first and second base frames to check for the presence of textual characters, (iii) selects a frame generation method based upon information in the first and second frames, (iv) filters the generated frames. In one embodiment, the system includes a server computer having an encoder, a client computer having a decoder, and a network connecting the server computer to the client computer.

Abstract: A method for handling missing or untimely synchronization signals in digital communications systems. Upon detecting the absence of a synchronization signal, an estimation of the absent synchronization signal is made based on a plurality of previously received synchronization signals, and the estimated synchronization signal is used in place of the absent synchronization signal. The estimated synchronization signal is corrected upon the receipt of a subsequent synchronization signal.

Abstract: A movement vector detecting device is provided with a movement vector detecting circuit for detecting a movement vector in each of blocks obtained by dividing an image frame, an edge number detecting circuit for detecting the number of edges in each of the blocks, and an evaluation circuit for evaluating the reliability of the movement vector value detected by the movement vector detecting circiut, based on the number of edges detected by the edge number detecting circuit.

Abstract: An image signal is input to an image processor for precessing, and motion vectors of an object in the input image signal are detected. A motion vector from among the detected motion vectors is identified which satisfies a predetermined condition, and predetermined processing is performed on the input image signal in accordance with the identification result. An image processing program is recorded on a computer readable recording medium for execution by the image processor to perform the predetermined processing.

Abstract: Vibration damping apparatus for vibrating environment such as a light emission microscope and an integrated circuit test head includes a rigid member with remotely controlled clamping apparatus attached to spaced portions of the member. The clamping apparatus engage the microscope and the test head for reducing vibrations, and the clamping apparatus can be readily deactivated for moving the microscope or the test head for alignment purposes. Advantageously, two or more rigid members including pneumatic cylinders can be positioned around the device under test while permitting the use of mechanical probes for engaging nodes of an integrated circuit for test purposes.

Abstract: A dequantization block is provided for performing dequantization calculations on a block of encoded video signal data using a modified standard quantization matrix. The modified standard quantization matrix is a product of a standard quantization matrix and a diagonal cosine matrix. The dequantization block receives a modified standard quantization matrix, the modified standard quantization matrix being a product of a standard quantization matrix corresponding to the encoded video data stream and a diagonal cosine matrix. In addition the dequantization block receives a scale representing a compression ratio of the encoded video data stream and non-zero IDCT coefficient matrix corresponding to a block of the encoded video data. The dequantization block then multiplies the scale, the non-zero IDCT coefficient matrix and the modified standard quantization matrix. An IDCT block is provided for performing IDCT calculations on each block processed by the dequantization block.

Abstract: A method and apparatus are provided for detecting a moving target in an observed environment wherein the observed environment includes the moving target and a scattering background. In the method, radiation is transmitted at the observed environment, and radiation is received from the observed environment. Temporal resolution channels are formed from both the transmitted and received radiation. The temporal resolution channels are coherently mixed and then averaged in time to produce an average integral coherent component channel. A non-coherent integral channel is formed from the received radiation. The average integral coherent component channel is normalized using the non-coherent integral channel to produce normalized components. The normalized components are compared and the presence of the moving target is determined based on the result of the comparison.

Abstract: A new motion estimation system and process for video compression is presented. The approach is computationally less expensive than typical spatial domain block matching algorithms. The search for matching blocks is performed in the frequency domain making extensive use of data already computed by the video encoding process. Moreover, additional good block matches can be recognized with this approach. A multi-tiered approach may be employed to combine the frequency domain analysis with existing spatial domain techniques.