Seiko Epson Corporation

Changick Kim

Vasudev Bhaskaran

William Chen

Joseph S Shu

Norihisa Hagiwara

An inter mode for encoding a video macroblock is selected. An initial analysis on the macroblock homogeneity is performed to quickly reduce the number of inter modes for which motion estimation and rate distortion calculation are to be performed. An inter mode is selected based on these calculations and sub-pixel motion estimation, at various sub-pixel interpolation granularities, is performed only on the selected inter mode. Sub-pixel motion estimation may be skipped for macroblocks that exhibit relatively low distortion at the integer pixel level.

Macroblock homogeneity analysis and inter mode prediction

Transform based distortion cost estimation, which may be used to calculate a rate distortion cost associated with a mode for encoding a macroblock, is described. In one embodiment of the invention, a distortion value for a particular mode is estimated within the transform domain, which allows for the elimination of both inverse transformation and inverse motion functions in this calculation. A spatial domain residual of an encoding mode is estimated by identifying a difference, within the transform domain, between a motion compensated prediction residual of a macroblock and its corresponding reconstructed signal. The estimated spatial domain residual may then be used in distortion matrix computations to estimate a distortion level, within the transform domain, for an encoding mode.

Transform domain based distortion cost estimation

An inter-mode for encoding a video macroblock is selected based on a comparison of at least two rate-distortion values associated with inter-modes. The number of potential inter-modes for encoding the video macroblock is initially reduced based on the rate-distortion calculation of the SKIP mode between the current macroblock and the collocated macroblock (corresponding to a 0,0 motion vector). Motion estimation is performed on the remaining inter-modes to identify reference blocks and motion vectors. The number of calculations performed in identifying the reference blocks and motion vectors is potentially reduced because associations between inter-modes are recognized and leveraged.

Motion estimation and inter-mode prediction

A prediction mode for encoding data is selected using a reduced number of rate-distortion cost computations. This reduction in rate-distortion cost computations is caused by filtering the number of potential intra prediction modes based on two criteria. First, the number of potential prediction modes is reduced based on at least one characteristic of a quantization procedure performed during the encoding procedure. Second, the number of potential prediction modes is reduced based on an error value calculated for each of the potential prediction modes.

Prediction intra-mode selection in an encoder

A method for smoothing artificial discontinuities between image blocks associated with digital data comprises reconstructing a block-based pixel representation of image blocks associated with digital data. If the difference between adjacent image blocks of the block-based pixel representation is less than or equal to a quantization parameter, then the method includes modifying boundary pixel values to define at least one additional frame, and displaying the at least one additional frame and an original frame in an alternating fashion so as to visually achieve smooth block boundaries between the adjacent image blocks. The method may be performed by a suitable device and/or may be embodied in an instruction set executable by such device.

Method and apparatus for video deblocking

A method for a matching technique for detecting copies of a video clip is provided. The method includes comparing temporal trails of intensity distributions between frames of the video clip and frames of a target video. A computer readable media, a computer system and integrated circuit for video copy detection are also provided.

Method and apparatus for video copy detection

A two-step matching technique is embodied in a video-copy-detection algorithm that detects copies of video sequences. The two-step matching technique uses ordinal signatures of frame partitions and their differences from partition mean values. The algorithm of this invention is not only robust to intensity/color variations it can also effectively handle various format conversions, thereby providing robustness regardless of the video dynamics of the frame shots.

Efficient and robust algorithm for video sequence matching

A 3-D dot code is embedded in a printed medium using an embedder that embeds data directly into the halftone dots of a selected file that is ready for printing. An extractor extracts the embedded bits by scanning the printed medium and then interprets the embedded data. A bleed-through elimination module in the extractor is able to eliminate adverse affects on the scanned input of the embedded data caused by bleed-through from the print on the opposite side of the page. The extractor may also include a module that compensates for a misaligned scanned input by automatically detecting the rotation and translation, and then registering the image so that the upper-left corner is located in a certain position. This operation expedites subsequent data retrieval, in which data is read by block matching.

3-Dimensional dot code for paper storage

A method for extracting an object of interest from an image is provided. The method initiates with defining an image feature space based upon frequency information. Then, the image feature space is filtered to smooth both focused regions and defocused regions while maintaining respective boundaries associated with the focused regions and the defocused regions. The filtered image feature space is manipulated by region merging and adaptive thresholding to extract an object-of-interest. A computer readable media, an image capture device and an image searching system are also provided.

Method and apparatus for low depth of field image segmentation

A method for encoding video data to reduce blocking artifacts is provided. The method initiates with identifying a macro-block as being associated with a blocking artifact. For example the macro-block may be identified as a low activity macro-block or a high activity macro-block. Then, blocking artifacts introduced through a compression operation are mitigated by adjusting both a quantization parameter and an amount of bits generated from the quantization parameter. A video encoder and a system for processing image data associated with block based compression are provided.

Method and apparatus for DCT domain filtering for block based encoding

A method for detecting a copy of a digital image initiates with dividing a suspected copy of a digital image into sub-images. Then, the average intensities associated with each of the sub-images is determined. Next, the average intensities are transformed into a series of coefficients. Then, a rank matrix from the series of coefficients is defined. Next, the rank matrix from the series of coefficients is compared to a rank matrix of a query image to determine if the suspected copy is an actual copy of the digital image. A computer readable media, a computer system and computer code configured to be executed on a computer system are also provided.

Method and apparatus for content-based image copy detection

A technique to reduce ringing artifacts in highly compressed block-based image/video coding is applied to each reconstructed frame output from the decoder. For each pixel block of a reconstructed frame, low-pass filtering is then adaptively applied according certain calculated differences between adjacent pixel values. For each pixel, a determination is made as to what type of horizontal filter, if any, is to be applied. Depending on the results of that determination, the pixel may remain unfiltered or may have a 2- or 3-tap horizontal filter applied to it. A similar process is undertaken to determine what type of vertical filter, if any, is to be applied, no filter, a 2-tap or a 3-tap vertical filter.

Adaptive post-filtering for reducing noise in highly compressed image/video coding

A method for reducing block artifacts between image blocks of a decompressed image is provided. The method initiates with selecting a set of pixel positions corresponding to pixels proximate to a border between the image blocks. Then, an amount of additional frames to be inserted when displaying the decompressed image is determined. Next, a pixel value associated with each pixel of the set of pixels proximate to the border is modified for each of the additional frames. Then, an original frame and the additional frames are displayed in an alternating mode such that block artifacts between the image blocks are visually reduced. A computer readable media, an integrated circuit and a device enabled to reduce blocking artifacts are also provided.

A technique to reduce blocking and ringing artifacts in low bit-rate block-based video coding is applied to each reconstructed frame output from the decoder. For each pixel block of a reconstructed frame, its DC value and DC values of the surrounding eight neighbor blocks are exploited to predict AC coefficients which might be lost in the quantization stage in the encoding process. The predicted AC coefficients are used to classify each reconstructed block as either a low-activity or a high-activity block. Low-pass filtering is then adaptively applied according to the classification of the block. Strong low-pass filtering is applied in low-activity blocks where the blocking artifacts are most noticeable, whereas weak low-pass filtering is applied in high-activity blocks where ringing noise as well as blocking artifacts may exist. The adaptive filtering reduces ringing noise as well as blocking artifacts without introducing undesired blur. In low activity blocks, the blocking artifacts are reduced by one dimensional horizontal and vertical low-pass filters which are selectively applied in either the horizontal and/or vertical direction depending on the locations and absolute values of the predicted AC coefficients. In high activity blocks, de-blocking and de-ringing is conducted by a single filter, applied horizontally and/or vertically, which makes the architecture simple.

Reducing blocking and ringing artifacts in low-bit-rate coding

A power-scalable hybrid technique to reduce blocking and ringing artifacts in low bit-rate block-based video coding is employed in connection with a modified decoder structure. Fast inverse motion compensation is applied directly in the compressed domain, so that the transform (e.g., DCT) coefficients of the current frame can be reconstructed from those of the previous frame. The spatial characteristics of each block is calculated from the DCT coefficients, and each block is classified as either low-activity or high-activity. For each low-activity block, its DC coefficient value and the DC coefficient values of the surrounding eight neighbor blocks are exploited to predict low frequency AC coefficients which reflect the original coefficients before quantization in the encoding stage. The predicted AC coefficients are inserted into the low activity blocks where blocking artifacts are most noticeable. Subject to available resources, this may be followed by spatial domain post-processing, in which two kinds of low-pass filters are adaptively applied, on a block-by-block basis, according to the classification of the particular block. Strong low-pass filtering is applied in low-activity blocks where the blocking artifacts are most noticeable, whereas weak low-pass filtering is applied in high-activity blocks where ringing noise as well as blocking artifacts may exist. In low activity blocks, the blocking artifacts are reduced by one dimensional horizontal and vertical low-pass filters which are selectively applied in either the horizontal and/or vertical direction depending on the locations and absolute values of the predicted AC coefficients. In high activity blocks, de-blocking and de-ringing is conducted by 2- or 3-tap filters, applied horizontally and/or vertically, which makes the architecture simple.

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Cupertino, CA, United States of America

Changick Kim