Abstract: A method for detecting scene cuts and similar pictures in a video sequence, including receiving pictures in a video sequence, extracting a set of features from two temporally consecutive pictures, computing a sum of square errors for the set of features with respect to the features of the previous picture, determining whether the error exceeds a predefined threshold and in response to the error exceeding the predefined threshold, detecting a scene change, and determining whether the error is less than a certain threshold thus detecting a similar picture has been found.

Abstract: A method of post-processing digital images frequency transforming a set of the pixels to a set of transformed coefficients; extracting original low-frequency coefficients and original high-frequency coefficients from the set of transformed coefficients; correcting the original low-frequency coefficients and the original high-frequency coefficients for delivering a set of corrected transformed coefficients including corrected low-frequency coefficients and corrected high-frequency coefficients; and combining the set of corrected transformed coefficients and the original high-frequency coefficients for delivering a set of combined transformed coefficients. The set of combined transformed coefficients are inverse frequency transformed for delivering a processed set of pixels that are ready for display on a screen.

Abstract: A method includes storing a current field of a digital video signal. The method further includes storing a preceding field that immediately precedes the current field in the digital video signal, and storing a succeeding field that immediately succeeds the current field in the digital video signal. The method also includes examining the preceding and succeeding fields for motion at a locus of a current pixel to be interpolated. In addition, if any motion at the locus is less than a threshold, the preceding and succeeding fields are examined for motion at a respective locus of at least one pixel that is adjacent to the current pixel to be interpolated.

Abstract: A method including, in some embodiments, comparing a preceding field and a succeeding field of a video signal for motion at a locus of a current pixel in a current field to be interpolated, in an instance of no motion determining which of a current pixel location in the preceding field and the succeeding field is closer to an estimate of a neighbor pixel and using the result of the determination to decide which of the preceding and succeeding fields to use to interpolate the current pixel based on symmetric spatial neighbors of the current pixel, and in an instance of motion interpolating the current pixel based on symmetric spatial neighbors of the current pixel at a line above and a line below the current pixel in the current frame.

Abstract: A method and system for estimating the quality of video data without gaining access to the source data, are configured to perform a Fast Fourier Transform (FFT) from at least some of the pixel values of the image in at least the horizontal direction, and at most, in the horizontal and vertical directions for the luminance and chrominance components. An average FFT is used to calculate kurtosis and skewness, then an image-quality metric is determined by calculating an offset from the kurtosis and skewness outputs.

Abstract: The present invention relates to a method and apparatus for generating a model used to estimate the quality of input-video data. The apparatus is configured to obtain a plurality of average subjective scores from a plurality of sample video data, and a plurality of image metrics for each of the plurality of said average subjective scores is calculated. Some of the plurality of said image metrics is converted into corresponding, perceived quality metrics, then an image-quality metric is predicted based on the calculated quality metrics and the perceived quality metrics.

Abstract: The present invention relates to a device for processing blocks of coded data included in a sequence of coded digital images (ES) according to a block-based coding technique, said device comprising a post-processing circuit DFD (33). Such a device effectively corrects the blocking artifacts while minimizing the bandwidth used, the decoder directly transmitting decoded data blocks (B) to the post-processing circuit. In addition, such a device introduces no or little drift during the decoding since the decoder continues to use reference images (RB) during a motion compensation step. This is because the reference images are no longer the decoded images but the completely processed images as the post-processing circuit is situated in the decoding loop.

Abstract: The present invention relates to a method and system for evaluating the quality of video data without gaining access to the source data. The system is configured to estimate sharpness metrics by detecting edge pixels and enclosing them with 8×8 pixel blocks. For each block, the sharpness according to the Kurtosis of the DCT is computed. The final metric is the average sharpness of the blocks in the edge profile and includes a robust combination of spatial and frequency domain information.

Abstract: The present invention relates to a method of measuring video quality. Said method comprises a step of determining (21) at least one reference level (JND) above which visual artifacts become noticeable to a group of subjects, with a corresponding predetermined artifact metric (M), from a set of reference sequences (RS) of digital pictures only comprising a corresponding artifact. The method of measuring video quality also comprises a step of measuring (22) at least one artifact level (L) of the input sequence (IS) with the corresponding predetermined artifact metric (M). It further comprises a step of computing (23) a video quality metric (OQM) of the input sequence from at least one ratio of the artifact level (L) to the reference level (JND) corresponding to a same predetermined artifact metric. Such a method of measuring video quality provides an objective quality metric.

Abstract: The invention relates to a method of post-processing digital images, the method comprising a step of frequency transformation TF (21), suitable for delivering a set of transformed coefficients (Y) from a set of pixels (y), extraction SEP (22) of original low-frequency coefficients (Ybfo) and original high-frequency coefficients (Yhfo) comprised in the set of transformed coefficients, correction COR (23), suitable for delivering a set of corrected transformed coefficients (Yc) from the original low-frequency coefficients, and combination (24), suitable for delivering a set of combined transformed coefficients (Yadd) from the original high-frequency coefficients and from the set of corrected transformed coefficients, and a step of inverse frequency transformation ITF (25) of the set of combined transformed coefficients, suitable for delivering a processed set of pixels (yout) that are ready for display on a screen.

Abstract: The present invention relates to a method and apparatus for generating a model used to estimate the quality of input-video data. The apparatus is configured to obtain a plurality of average subjective scores from a plurality of sample video data, and a plurality of image metrics for each of the plurality of said average subjective scores is calculated. Some of the plurality of said image metrics is converted into corresponding, perceived quality metrics, then an image-quality metric is predicted based on the calculated quality metrics and the perceived quality metrics.

Abstract: The present invention relates to a method and system for estimating the quality of video data without gaining access to the source data. The system is configured to perform a Fast Fourier Transform (FFT) from at least some of the pixel values of the image in at least the horizontal direction, and at most in the horizontal and vertical directions for the luminance and chrominance components. An average FFT is used to calculate kurtosis and skewness, then an image-quality metric is determined by calculating an offset from the kurtosis and skewness outputs.

Abstract: The present invention relates to a method and system for estimating the quality of encoded video data without gaining access to the source data. The system is configured to decode compressed video data using an MPEG/H.263 decoder to produce decompressed video data. The decoded data is subject to a discrete cosine transform (DCT) to produce a set of DCT coefficients of the decompressed video data is determined to be intra-coded. Meanwhile, the quantization matrix including a quantizier step size for each block of the decompressed video data are extracted. Following this, statistical properties of the DCT coefficients are extracted from the decoded video. Then, an average quantization error for both AC and DC coefficients is determined using information regarding the quantization and the statistical properties. Finally, this estimated quantization error is used for in computing a peak signal to noise ratio (PSNR).

Abstract: The present invention relates to a method and system for evaluating the quality of video data without gaining access to the source data. The system is configured to estimate sharpness metrics by detecting edge pixels and enclosing them with 8×8 pixel blocks. For each block, the sharpness according to the Kurtosis of the DCT is computed. The final metric is the average sharpness of the blocks in the edge profile and includes a robust combination of spatial and frequency domain information.

Abstract: The invention relates to a communication method and a terminal (500) for use with such a method. The method uses at least two interconnected terminals (402, 404), at which input data from associated participants is captured. The input data comprises at least video and/or audio data. A monitoring unit (530) derives activity information about the participants from the input data. The monitoring unit (530) is either located in one terminal (402) for centrally deriving the activity information, or present in all terminals (402, 404) for, at least partly, deriving the activity information locally. The activity information is subsequently visualized in the form of tables and/or diagrams or by manipulating the windows in which the participants are displayed. Also this visualization step can be performed only at a central terminal (402) or at the terminal of each participant (402, 404). The activity information comprises for instance talking time and a number of key strokes of the participant.

Abstract: The invention relates to a communication method and a terminal (500) for use with such a method. The method uses at least two interconnected terminals (402, 404), at which input data from associated participants is captured. The input data comprises at least video and/or audio data. A monitoring unit (530) derives activity information about the participants from the input data. The monitoring unit (530) is either located in one terminal (402) for centrally deriving the activity information, or present in all terminals (402, 404) for, at least partly, deriving the activity information locally. The activity information is subsequently visualized in the form of tables and/or diagrams or by manipulating the windows in which the participants are displayed. Also this visualization step can be performed only at a central terminal (402) or at the terminal of each participant (402, 404). The activity information comprises for instance talking time and a number of key strokes of the participant.

Abstract: The present invention relates to a method of measuring video quality. Said method comprises a step of determining (21) at least one reference level (JND) above which visual artifacts become noticeable to a group of subjects, with a corresponding predetermined artifact metric (M), from a set of reference sequences (RS) of digital pictures only comprising a corresponding artifact. The method of measuring video quality also comprises a step of measuring (22) at least one artifact level (L) of the input sequence (IS) with the corresponding predetermined artifact metric (M). It further comprises a step of computing (23) a video quality metric (OQM) of the input sequence from at least one ratio of the artifact level (L) to the reference level (JND) corresponding to a same predetermined artifact metric. Such a method of measuring video quality provides an objective quality metric.

Abstract: The present invention relates to a device for processing blocks of coded data included in a sequence of coded digital images (ES) according to a block-based coding technique, said device comprising a post-processing circuit DFD (33). Such a device effectively corrects the blocking artifacts while minimizing the bandwidth used, the decoder directly transmitting decoded data blocks (B) to the post-processing circuit. In addition, such a device introduces no or little drift during the decoding since the decoder continues to use reference images (RB) during a motion compensation step. This is because the reference images are no longer the decoded images but the completely processed images as the post-processing circuit is situated in the decoding loop.

Abstract: The present invention relates to a method of and an arrangement for processing data comprised in a digital input image. Said arrangement comprises a decoder unit (20) intended for transmitting a decoded analog image (S2) to a television receiver (27) via a channel CH (23). The decoder unit includes a device MPD (21) by means of which the encoded digital image (S1) can be decoded and a digital to analog converter DAC (22). The television receiver includes an analog to digital converter ADC (24) intended for supplying a digital input image (S3) to a device DET (25) by means of which it is possible to detect if said digital input image has been encoded in accordance with a block-based encoding technique. A correction or post-processing device COR (26), whose operation depends on the data supplied by the detection device, thus enables the display quality of the digital image to be improved in view of its display on the screen.