公开(公告)号：US06950473B2

公开(公告)日：2005-09-27

申请号：US10176994

申请日：2002-06-21

Applicant: Changick Kim ,  William Chen ,  Vasudev Bhaskaran

Inventor： Changick Kim ,  William Chen ,  Vasudev Bhaskaran

IPC: H04N7/26 ,  H04N7/30 ,  H04N7/12

CPC classification number: H04N19/86

Abstract: 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.

Abstract translation: 结合经修改的解码器结构采用功率可扩展的混合技术来减少低比特率基于块的视频编码中的阻塞和振铃伪影。 快速逆运动补偿直接应用在压缩域中，使得当前帧的变换（例如DCT）系数可以从先前帧的变换（例如，DCT）系数重构。 根据DCT系数计算每个块的空间特性，将每个块分类为低活动度或高活动度。 对于每个低活动块，利用其DC系数值和周围八个相邻块的DC系数值来预测在编码阶段中反映量化之前的原始系数的低频AC系数。 将预测的AC系数插入到低活动块中，其中块伪影最显着。 根据可用资源，可以跟随空间域后处理，其中根据特定块的分类，在逐块的基础上自适应地应用两种低通滤波器。 强低通滤波被应用在低活动性块中，其中块伪影是最显着的，而弱低通滤波被应用于可能存在振铃噪声和块伪影的高活动块中。 在低活动性块中，根据预测的AC系数的位置和绝对值，在水平和/或垂直方向选择性地施加一维水平和垂直低通滤波器来减少块伪影。 在高活动性块中，通过水平和/或垂直施加的2或3抽头滤波器进行解块和解除振铃，这使得架构变得简单。

公开(公告)号：US20050024387A1

公开(公告)日：2005-02-03

申请号：US10631072

申请日：2003-07-31

Applicant: Viresh Ratnakar ,  Vasudev Bhaskaran

Inventor： Viresh Ratnakar ,  Vasudev Bhaskaran

IPC: G06T11/80 ,  G06T3/00 ,  G06T11/60 ,  G09G5/00 ,  G09G5/36 ,  G09G5/377

CPC classification number: G06T11/60

Abstract: A layered presentation system (LAPE) includes a server that performs compressed-domain image processing on image data received from multiple clients including a master client and other clients to generate a composite image that incorporates imagery from the other clients with a master image from the master client for viewing on a shared display. The system's clients can add imagery in the form of questions, comments, and graphics to a currently displayed image. The added imagery is processed along with the master image to generate the composite image that then appears on the shared display and perhaps also on each client's individual display. The processing includes scaling the master image/added imagery, as required, and blending and/or overlaying the added imagery onto the master image so as to augment but not obscure it. A network protocol is included for sending image data in the compressed domain back and forth between the server and each of the clients.

Abstract translation: 分层呈现系统（LAPE）包括对从包括主客户端和其他客户端的多个客户端接收的图像数据执行压缩域图像处理的服务器，以生成包含来自其他客户机的图像的合成图像，其中主图像来自主设备 客户端在共享显示器上查看。 系统的客户端可以将问题，评论和图形的形象添加到当前显示的图像中。 添加的图像将与主图像一起处理，以生成合成图像，然后出现在共享显示屏上，也可能在每个客户端的单个显示屏上。 处理包括根据需要缩放主图像/添加的图像，并将添加的图像混合和/或叠加到主图像上，以便增加但不使其模糊。 包括网络协议，用于在服务器与每个客户端之间来回传送压缩域中的图像数据。

公开(公告)号：US06421468B1

公开(公告)日：2002-07-16

申请号：US09226370

申请日：1999-01-06

Applicant: Viresh Ratnakar ,  Vasudev Bhaskaran

Inventor： Viresh Ratnakar ,  Vasudev Bhaskaran

IPC: H04N712

CPC classification number: G06T3/4084 ,  G06T5/003 ,  G06T5/10 ,  G06T2207/20192 ,  H04N1/4092 ,  H04N5/208

Abstract: An original image is sharpened by obtaining a first frequency-domain representation of the original image, selecting one or more elements from this first representation based on one more criteria such as element magnitude and frequency, scaling the selected elements according to one or more scale factors, and forming a second frequency-domain representation by combining the scaled selected elements with the unselected elements of the first representation. A sharpened reproduction of the original image may be generated by applying an inverse transform to the second frequency-domain representation. A technique for deriving the value of the one or more scale factors is also discussed.

Abstract translation: 通过获得原始图像的第一频域表示来锐化原始图像，基于诸如元素幅度和频率的多个标准从该第一表示中选择一个或多个元素，根据一个或多个比例因子对所选择的元素进行缩放 ，以及通过将缩放的所选择的元素与第一表示的未选择元素组合来形成第二频域表示。 可以通过对第二频域表示应用逆变换来生成原始图像的锐化再现。 还讨论了用于导出一个或多个比例因子的值的技术。

公开(公告)号：US6057882A

公开(公告)日：2000-05-02

申请号：US738620

申请日：1996-10-29

Applicant: Christian J. van den Branden Lambrecht ,  Vasudev Bhaskaran ,  Albert W. Kovalick ,  Murat Kunt

Inventor： Christian J. van den Branden Lambrecht ,  Vasudev Bhaskaran ,  Albert W. Kovalick ,  Murat Kunt

IPC: H04B17/00 ,  H04N17/00

CPC classification number: H04B17/0085 ,  H04N17/004

Abstract: An automatic testing method and device is described that can test a video sequence coder/decoder system and either assess the quality of decoded sequences or rate the fidelity of the coding chain. The device produces synthetic test patterns that induce the appearance of known artifacts, then tracks and evaluates such artifacts. Based on this evaluation, it can rate the system's performance in a way that correlates well with human assessments. In our testing device, the quality estimation module performs this function.

Abstract translation: 描述了可以测试视频序列编码器/解码器系统并且评估解码序列的质量或评价编码链的保真度的自动测试方法和装置。 该设备产生合成测试图案，其引起已知工件的出现，然后跟踪并评估此类工件。 基于此评估，它可以以与人类评估相关的方式对系统的绩效进行评级。 在我们的测试设备中，质量估算模块执行此功能。

公开(公告)号：US5708732A

公开(公告)日：1998-01-13

申请号：US611922

申请日：1996-03-06

Applicant: Neri Merhav ,  Vasudev Bhaskaran

Inventor： Neri Merhav ,  Vasudev Bhaskaran

IPC: G06T3/40 ,  G06T9/00 ,  G11B27/034 ,  H03M7/30 ,  H03M7/40 ,  H04N7/26 ,  H04N7/30 ,  H04N7/36 ,  H04N7/46 ,  H04N7/50 ,  G06K9/36 ,  G06F17/14 ,  H04N7/12

CPC classification number: G11B27/034 ,  G06T3/4084 ,  H04N19/40 ,  H04N19/42 ,  H04N19/48 ,  H04N19/51 ,  H04N19/59 ,  H04N19/61

Abstract: Downsampling and inverse motion compensation are performed on compressed domain representations for video. By directly manipulating the compressed domain representation instead of the spatial domain representation, computational complexity is significantly reduced. For downsampling, the compressed stream is processed in the compressed (DCT) domain without explicit decompression and spatial domain downsampling so that the resulting compressed stream corresponds to a scaled down image, ensuring that the resulting compressed stream conforms to the standard syntax of 8.times.8 DCT matrices. For typical data sets, this approach of downsampling in the compressed domain results in computation savings around 80% compared with traditional spatial domain methods for downsampling from compressed data. For inverse motion compensation, motion compensated compressed video is converted into a sequence of DCT domain blocks corresponding to the spatial domain blocks in the current picture alone. By performing inverse motion compensation directly in the compressed domain, the reduction in computation complexity is around 68% compared with traditional spatial domain methods for inverse motion compensation from compressed data. The techniques for downsampling and inverse motion compensation can be used in a variety of applications, such as multipoint video conferencing and video editing.

Abstract translation: 对视频的压缩域表示进行下采样和逆运动补偿。 通过直接操纵压缩域表示而不是空间域表示，计算复杂度显着降低。 对于下采样，压缩流在压缩（DCT）域中被处理，而没有显式解压缩和空域降序采样，使得所生成的压缩流对应于缩小图像，确保得到的压缩流符合8×8 DCT矩阵的标准语法 。 对于典型的数据集，与压缩数据下采样的传统空间域方法相比，压缩域中的这种下采样方法导致计算节省大约80％。 对于逆运动补偿，运动补偿压缩视频被转换成与当前图像中的空间域块相对应的DCT域块序列。 通过直接在压缩域中进行逆运动补偿，与传统的空间域方法相比，压缩数据的反向运动补偿的计算复杂度降低了约68％。 用于下采样和反向运动补偿的技术可用于各种应用，如多点视频会议和视频编辑。

公开(公告)号：US09509970B2

公开(公告)日：2016-11-29

申请号：US13552370

申请日：2012-07-18

Applicant: Gokce Dane ,  Vasudev Bhaskaran

Inventor： Gokce Dane ,  Vasudev Bhaskaran

IPC: H04N13/00

CPC classification number: H04N13/122 ,  H04N13/144

Abstract: In one example, a method includes identifying a pixel in an image frame that is a candidate for causing crosstalk between the image frame and a corresponding image frame in a multiview image system. The method further includes, for a pixel identified as a candidate for causing crosstalk, applying crosstalk correction to the pixel. The method further includes applying a location-based adjustment to the pixel, wherein the location-based adjustment is based at least in part on which of two or more portions of the image frame the pixel is in.

Abstract translation: 在一个示例中，一种方法包括识别图像帧中的像素，其是在多视图图像系统中引起图像帧与对应图像帧之间的串扰的候选。 该方法还包括对于被识别为引起串扰的候选的像素，对像素应用串扰校正。 该方法还包括对像素应用基于位置的调整，其中基于位置的调整至少部分地基于像素在图像帧的两个或多个部分中的哪一个。

公开(公告)号：US09232226B2

公开(公告)日：2016-01-05

申请号：US12542519

申请日：2009-08-17

Applicant: Vasudev Bhaskaran ,  Nikhil Balram

Inventor： Vasudev Bhaskaran ,  Nikhil Balram

IPC: H04N7/12 ,  H04N19/154 ,  H04N19/103 ,  H04N19/176 ,  H04N19/63 ,  H04N19/61 ,  H04N19/12 ,  H04N19/14 ,  H04N19/186 ,  H04N19/115 ,  H04N19/146

CPC classification number: H04N19/154 ,  H04N19/103 ,  H04N19/115 ,  H04N19/12 ,  H04N19/14 ,  H04N19/146 ,  H04N19/176 ,  H04N19/186 ,  H04N19/61 ,  H04N19/63

Abstract: Systems and methods for compressing video data are provided. The method includes segmenting a video frame, selecting a coding mode, and encoding. The segmenting includes segmenting the video frame of the video data into a sequence of coding blocks. The selecting includes selecting the coding mode from a plurality of coding modes. The selecting of the coding mode is based on an allowable bit budget and occurs for each coding block. The encoding includes encoding each coding block based on the coding mode. The allowable bit budget varies according to a bit utilization of prior encoded coding blocks and varies such that the video frame does not exceed a specified compression ratio.

Abstract translation: 提供了压缩视频数据的系统和方法。 该方法包括分割视频帧，选择编码模式和编码。 分割包括将视频数据的视频帧分割成编码块序列。 选择包括从多个编码模式中选择编码模式。 编码模式的选择基于允许的比特预算，并且针对每个编码块出现。 编码包括基于编码模式对每个编码块进行编码。 可允许的比特预算根据先前编码的编码块的比特利用而变化，并且变化使得视频帧不超过指定的压缩比。

公开(公告)号：US20140022340A1

公开(公告)日：2014-01-23

申请号：US13552370

申请日：2012-07-18

Applicant: Gokce Dane ,  Vasudev Bhaskaran

Inventor： Gokce Dane ,  Vasudev Bhaskaran

IPC: H04N13/00

CPC classification number: H04N13/122 ,  H04N13/144

Abstract: In one example, a method includes identifying a pixel in an image frame that is a candidate for causing crosstalk between the image frame and a corresponding image frame in a multiview image system. The method further includes, for a pixel identified as a candidate for causing crosstalk, applying crosstalk correction to the pixel. The method further includes applying a location-based adjustment to the pixel, wherein the location-based adjustment is based at least in part on which of two or more portions of the image frame the pixel is in.

Abstract translation: 在一个示例中，一种方法包括识别图像帧中的像素，其是在多视图图像系统中引起图像帧与对应图像帧之间的串扰的候选。 该方法还包括对于被识别为引起串扰的候选的像素，对像素应用串扰校正。 该方法还包括对像素应用基于位置的调整，其中基于位置的调整至少部分地基于像素在图像帧的两个或多个部分中的哪一个。

公开(公告)号：US20140022339A1

公开(公告)日：2014-01-23

申请号：US13552340

申请日：2012-07-18

Applicant: Gokce Dane ,  Vasudev Bhaskaran

Inventor： Gokce Dane ,  Vasudev Bhaskaran

IPC: H04N13/00

CPC classification number: H04N13/144

Abstract: In one example, a method includes identifying a first set of pixels in co-located pairs in a corresponding pair of multiview image frames for which the co-located pairs have a disparity between the pixels that is greater than a selected disparity threshold. The method further includes identifying a second set of pixels in at least one of the image frames that are within a selected distance of an intensity transition greater than a selected intensity transition threshold. The method further includes applying crosstalk correction to pixels that are identified as being in at least one of the first set and the second set.

Abstract translation: 在一个示例中，一种方法包括识别对应的多视图图像帧对中的同位置对中的第一组像素，其中同位置对具有大于所选视差阈值的像素之间的差异。 该方法还包括识别在大于所选择的强度转变阈值的强度转换的选定距离内的至少一个图像帧中的第二组像素。 该方法还包括对被识别为处于第一组和第二组中的至少一个的像素应用串扰校正。

公开(公告)号：US20080056366A1

公开(公告)日：2008-03-06

申请号：US11469699

申请日：2006-09-01

Applicant: Vasudev Bhaskaran

Inventor： Vasudev Bhaskaran

IPC: H04N11/02 ,  H04B1/66

CPC classification number: H04N19/573 ,  H04N19/51 ,  H04N19/82 ,  H04N19/86

Abstract: An apparatus and method are described for filtering noise internally within a video encoding framework. In various embodiments of the invention, an in-loop noise filter is integrated within an encoding device or framework that reduces noise along a motion trajectory within a digital video signal. This integration of in-loop noise reduction allows both noise filtering parameters and encoding parameters to be more easily related and adjusted. The in-loop noise filter leverages characteristics of digital video encoding processes to reduce noise on a video signal and improve encoding efficiencies of a codec.

Abstract translation: 描述了用于在视频编码框架内部内部滤波噪声的装置和方法。 在本发明的各种实施例中，将环路噪声滤波器集成在编码设备或框架内，以减少沿着数字视频信号内的运动轨迹的噪声。 这种内置环路噪声降低的集成允许噪声滤波参数和编码参数更容易相关和调整。 环路噪声滤波器利用数字视频编码处理的特性来降低视频信号的噪声并提高编解码器的编码效率。