Abstract: An image processing apparatus which conceals image data in accordance with motion data includes an input unit for inputting information data including motion data and image data encoded in accordance with the motion data, a detection unit for detecting error codes in the image data, and a concealment unit for concealing the image data by replacing it by image data of an adjacent picture frame extracted using the motion data.

Abstract: In a method and a circuit for detecting and concealing video signal errors caused by vertically extending film scratches during television film scanning, an error signal is derived at error locations generated by disturbed pixels and is used in the form of a control signal for concealing errors in the video signal. The error signal is generated only when an adjustable, locally bounded scratch width in the horizontal direction is not exceeded and when each scratch essentially extends vertically, and when the scratch length substantially corresponds to the film frame height. Finally, the disturbed locations in the video signal are replaced by the corresponding low-pass-filtered video signal with the aid of the error signal.

Abstract: The order of pixel data is converted on a frame-by-frame basis to produce a prescribed combination of pixel data. To construct frames, sequence numbers representing the order of the frames are attached to respective frame data each composed of a plurality of pixel data thus produced. The frames thus constructed are transmitted to the transmission line. On the receiving side, the sequence numbers of the frames received from the transmission line are checked to detect a missing frame. Pixel data of the missing frame is replaced by those of a frame having a sequence number immediately before that of the missing frame. An image is reconstructed by inversely converting the order of the pixel data which include the replaced pixel data.

Abstract: An apparatus includes a reproducing circuit for reproducing an encoded image signal from a recording medium, a decoding circuit for decoding the image signal reproduced by the reproducing circuit, a movement detection circuit for detecting a movement of an image signal which cannot be detected by the decoding circuit, and outputting a signal indicating the movement level of the undecodable signal, and a construction circuit for constructing an image signal with respect to the undecodable image signal on the basis of the output from the movement detection means. Even when an undecodable image signal is an intermediate signal between signals with and without a movement, a good reproduced image is obtained.

Abstract: A moving picture receiving method for receiving a moving picture by block unit includes steps of detecting a lost block which can not be reproduced in the receiving image signal, calculating an average value of blocks adjacent to the lost block which can not be reproduced, adaptively substituting the lost block by an average value of the block adjacent to the lost block or a block at the same location corresponding to the preceding frame in case that the block is lost in the receiving signal.

Abstract: An electronic still camera includes a plurality of image pickup elements having color filters of a plurality of colors; a color separation unit for separating outputs from the image pickup elements into each color signal; an interpolation unit for receiving an output from the color separation unit and interpolating missing part of each color image data; an orthogonal transformation unit for dividing respective color image data interpolated by the interpolation unit into a plurality of blocks and performing orthogonal transformation, a coding unit for coding an output from the orthogonal transformation unit; and a storage unit for storing an output from the coding unit.

Abstract: An apparatus for concealing error data of pixel data in a digital image signal. The apparatus includes a deframing circuit for detecting errors every predetermined unit to generate a first error flag in high order bit planes including at least the most significant bit plane of bit planes of pixel data in a received digital image signal and for forming a second error flag representing the presence or absence of an error in each of the bits forming the pixel data every pixel data in the high order bit planes on the basis of the first error flag. The apparatus further includes an error correcting device for calculating a plurality of possible data values of the pixel data and for selecting one data value from among the plurality of possible data values, taking the correlation between the pixel data and surrounding pixel data into consideration, on the basis of the second error flag representing the presence or absence of an error in each of the bits forming the pixel data when the pixel data has an error.

Abstract: A novel method for concealing or rectifying channel errors present in a decoded image signal which has been transmitted in a compressed form by using a classified vector quantization technique comprises a step for estimating the class for a current block by detecting boundary edges at each of four groups of neighboring pixels; and a step for estimating the representative vector for the current block by calculating a multiple number of side-matching functions and choosing the candidate vector producing the smallest side-matching function as the representative vector for the current block.

Abstract: An image signal processing device is arranged to convert an analog image signal into a digital image signal after the analog image signal is clamped, to separate, in the form of a digital signal, a synchronizing signal from the digital image signal and to control a clamping action on the analog image signal according to a state of the separated digital synchronizing signal. The arrangement enables the device to always stably perform the clamping action.

Abstract: A video signal noise reduction system is disclosed in which corresponding image pixels from a current frame and image pixels from a noise reduced previous frame are averaged to produce respective noise reduced pixel values. In the disclosed exemplary embodiment of the invention, a processed frame memory stores a noise reduced image and a motion estimator identifies a target block of pixels in this processed frame memory to be used in calculating a noise reduced video signal. A motion compensated noise reduction processor combines the block of the noise reduced image pixels stored in the processed frame memory with a current block of pixels generated from the video signal to produce a motion block of noise reduced pixels. The relative weighting applied to the stored pixel and the current pixel depends on the number of pixels that were used to generate the stored pixel.

Abstract: A frequency drop out compensating circuit and method thereof is applicable to the signals of both NTSC and PAL systems. The frequency drop out compensating circuit for NTSC/PAL systems in an optical disk system including an amplifier for amplifying an applied FM signal, a pulse generator for converting the frequency drop out signal detected from the amplified FM signal into a pulse signal and a drop out compensator for compensating the drop out when a frequency drop for the signal generated from the pulse generator is generated, has an integrator for integrating the FM signal generated from the amplifier and an integrating current controller for controlling the integrating current of the integrator according to the applied FM signal. Therefore, drop out can be detected and compensated in signals for both NTSC and PAL systems, by controlling the integrating current in consideration of the FM band utilized.

Abstract: An apparatus for concealing an error of a moving pictures transform coding includes the first concealment circuit (19) for analyzing data according to a type of the data, the data being error-detected but not corrected by an error correction decoding by the decoder (12), for replacing the data with a specific data according to the analyzed result by using a predetermined method, and for outputting a specific signal therefrom, and the second concealment circuit (22) connected to the first concealment circuit (19) for replacing reproduced pixel values of an error-occurred block with reproduced pixel values of a previous frame according to the signal output from the first concealment circuit (19) in case that the data being error-detected but not corrected is data of a predetermined frequency component or data of an additional information.

Abstract: A coded digital video signal is obtained by dividing a digital video signal into plural pages each composed of K fields of pixel data, decomposing pixel data in each two pages into plural blocks each composed of a predetermined number of pixel data, and encoding the pixel data in each block by bit rate reduction encoding and error correction encoding. The thus obtained coded digital video signal is reproduced or transmitted and then subjected to a concealment process. The concealment process includes decoding the coded digital video signal to obtain reproduced blocks of pixel data and to detect an error block containing an error among the reproduced blocks, composing the reproduced blocks to obtain plural reproduced pages of pixel data, and concealing error pixel data contained in the error block in each two reproduced pages. Error pixel data in a first page is concealed using pixel data in a previous page, and error pixel data in a second page is concealed using pixel data in a succeeding page.

Abstract: A median filter adaptively increases a window size when there is a possibility that an impulse noise will be present in the median value. When it is determined that an impulse noise is not present in the median value obtained as a median-filtering result, the median filter checks whether or not an impulse noise is present in a target pixel value which is to be subjected to median filtering. When there is a possibility that an impulse noise is present in the target pixel value, the median filter outputs the median value. On the other hand, when an impulse noise is not present in the median value as a check result, the median filter outputs the input target pixel value. Accordingly, an impulse noise can be effectively eliminated from a video signal mixed with a positive impulse noise and a negative impulse noise, while the edge change of the video signal produced by the median filter itself can be minimized. An adaptive median filter is also described.

Abstract: A drop-out compensator for a video reproducing apparatus comprises a switch device for selectively outputting a reproduced video signal and a 1H-delayed signal in response to a drop-out detecting signal, a 1H delay circuit for delaying a video signal whose drop-out is compensated and which is output via the switch device, and an automatic level control device for comparing the synchronous signal levels of the reproduced video signal and 1H-delayed signal, amplifying the 1H-delayed signal output from the 1H delay circuit in response to the result of the comparison, thereby adjusting the level of the 1H-delayed signal to be supplied to the switch device to match that of the reproduced video signal. The compensator can automatically adjust the amplitude of a drop-out-compensated signal by comparing the levels of the synchronous signal of a reproduced video signal and the synchronous signal of a 1H-delayed signal and matching the amplitudes of 1H-delayed signal and the reproduced video signal.

Abstract: A digital video editing apparatus in which the frame number information that is encoded in non-visible portions of frames in an analog video signal is utilized to ensure that there are no missing frames of corresponding digital video information. The frames of analog video information are digitized and stored in the editing apparatus using a two-pass procedure. In the first pass, as many analog video frames as possible are digitized and stored, and the frame numbers from the frames are utilized to form a list of missing frames. In the second pass, the missing frame list is utilized to reposition the analog video source and to read in the missing frames. If desired, a digital frame trap may be provided such that the contents of a temporary frame memory are frozen until computer processing apparatus has enough time permanently to store the trapped frame.

Abstract: Error concealment apparatus for correcting errors in signals representing video images includes means for detecting image gradients in an area surrounding a lost block of image data. Circuitry responsive to these image gradients generates a plurality of blocks of directionally interpolated pixel values. The pixel values in the respective blocks of directionally interpolated pixel values are sorted according to amplitude, and then pixel values from mutually exclusive positions in the respective blocks are selected to form a block of pixel values for error concealment.

Abstract: Error concealment apparatus for concealing corrupted data elements in frequency separated digital image data (such as sub-band coded image data) is described. Depending on the spatial frequency represented by a corrupted data element, one of a number of error concealment means is selected to conceal the error. In this way the error concealment used can be tailored to suit the different properties of the various spatial frequency components in the frequency separated image.

Abstract: A horizontal edge compensation circuit includes a delay circuit for delaying an input luminance signal for a certain time, a waveform converter for differentiating the input luminance signal to take its absolute value, and reshaping the waveform of the signal, a quantization circuit for differentiating again the first differentiated signal, comparing to predetermined reference levels the first differentiated signal obtained by emphasizing a signal having a low level difference and bypassing a signal having a high level difference, and then generating a code signal to quantize the second differentiated signal, a gain controller for selectively multiplying the reshaped signal according to the code signal, and controlling the degree of horizontal edge compensation, and an adder for adding the luminance signal delayed for a certain time in the delay circuit to the horizontal edge compensation signal output from the gain control portion.

Abstract: A dropout compensation device includes a plurality of video signal storage devices, e.g., capacitors, for storing video signals to be displayed, a dropout detection circuit for detecting video signal dropout, and a circuit for interrupting the supply of video signals to the storage circuits whenever a dropout is detected, with the display continuing in accordance with what is already stored, e.g., from the previous line of video before the dropout was detected.