In-loop filters have been comprehensively explored during the development of video coding standards due to their remarkable noise-reduction capabilities.In the early stage of video coding,in-loop filters,such as the d...In-loop filters have been comprehensively explored during the development of video coding standards due to their remarkable noise-reduction capabilities.In the early stage of video coding,in-loop filters,such as the deblocking filter,sample adaptive offset,and adaptive loop filter,were performed separately for each component.Recently,cross-component filters have been studied to improve chroma fidelity by exploiting correlations between the luma and chroma channels.This paper introduces the cross-component filters used in the state-ofthe-art video coding standards,including the cross-component adaptive loop filter and cross-component sample adaptive offset.Crosscomponent filters aim to reduce compression artifacts based on the correlation between different components and provide more accurate pixel reconstruction values.We present their origin,development,and status in the current video coding standards.Finally,we conduct discussions on the further evolution of cross-component filters.展开更多
Joint Radar and Communications(JRC)can implement two Radio Frequency(RF)functions using a single of resources,providing significant hardware,power and spectrum savings for wireless systems requiring both functions.Fre...Joint Radar and Communications(JRC)can implement two Radio Frequency(RF)functions using a single of resources,providing significant hardware,power and spectrum savings for wireless systems requiring both functions.Frequency-Hopping(FH)MIMO radar is a popular candidate for JRC because the achieved communication symbol rate can greatly exceed the radar pulse repetition frequency.However,practical transceiver imperfections can cause many existing theoretical designs to fail.In this work,we reveal for the first time the non-trivial impact of hardware imperfections on FH-MIMO JRC and model the impact analytically.We also design new waveforms and correspondingly develop a low-complexity algorithm to jointly estimate the hardware imperfections of unsynchronized receiver.In addition,using low-cost software-defined radios and Commercial Off-The-Shelf(COTS)products,we build the first FH-MIMO JRC experimental platform with simultaneous over-the-air radar and communication validation.Confirmed by simulation and experimental results,the proposed designs achieve high performance for both radar and communications.展开更多
This paper presents a high-speed column-parallel cyclic analog-to-digital converter（ADC） for a CMOS image sensor.A correlated double sampling（CDS） circuit is integrated in the ADC,which avoids a stand-alone CDS ci...This paper presents a high-speed column-parallel cyclic analog-to-digital converter（ADC） for a CMOS image sensor.A correlated double sampling（CDS） circuit is integrated in the ADC,which avoids a stand-alone CDS circuit block.An offset cancellation technique is also introduced,which reduces the column fixed-pattern noise（FPN） effectively.One single channel ADC with an area less than 0.02 mm^2 was implemented in a 0.13μm CMOS image sensor process.The resolution of the proposed ADC is 10-bit,and the conversion rate is 1.6 MS/s. The measured differential nonlinearity and integral nonlinearity are 0.89 LSB and 6.2 LSB together with CDS, respectively.The power consumption from 3.3 V supply is only 0.66 mW.An array of 48 10-bit column-parallel cyclic ADCs was integrated into an array of CMOS image sensor pixels.The measured results indicated that the ADC circuit is suitable for high-speed CMOS image sensors.展开更多
A learning-based adaptive loop filter is developed for the geometry-based point-cloud compression(G-PCC)standard to reduce attribute compression artifacts.The proposed method first generates multiple most probable sam...A learning-based adaptive loop filter is developed for the geometry-based point-cloud compression(G-PCC)standard to reduce attribute compression artifacts.The proposed method first generates multiple most probable sample offsets(MPSOs)as potential compression distortion approximations,and then linearly weights them for artifact mitigation.Therefore,we drive the filtered reconstruction as closely to the uncompressed PCA as possible.To this end,we devise an attribute artifact reduction network(ARNet)consisting of two consecutive processing phases:MPSOs derivation and MPSOs combination.The MPSOs derivation uses a two-stream network to model local neighborhood variations from direct spatial embedding and frequency-dependent embedding,where sparse convolutions are utilized to best aggregate information from sparsely and irregularly distributed points.The MPSOs combination is guided by the least-squares error metric to derive weighting coefficients on the fly to further capture the content dynamics of the input PCAs.ARNet is implemented as an in-loop filtering tool for GPCC,where the linear weighting coefficients are encapsulated into the bitstream with negligible bitrate overhead.The experimental results demonstrate significant improvements over the latest G-PCC both subjectively and objectively.For example,our method offers a 22.12%YUV Bjøntegaard delta rate(BDRate)reduction compared to G-PCC across various commonly used test point clouds.Compared with a recent study showing state-of-the-art performance,our work not only gains 13.23%YUV BD-Rate but also provides a 30×processing speedup.展开更多
基金supported in part by National Science Foundation of China under Grant No.62031013PCL-CMCC Foundation for Science and Innovation under Grant No.2024ZY1C0040+1 种基金New Cornerstone Science Foundation for the Xplorer PrizeHigh performance Computing Platform of Peking University。
文摘In-loop filters have been comprehensively explored during the development of video coding standards due to their remarkable noise-reduction capabilities.In the early stage of video coding,in-loop filters,such as the deblocking filter,sample adaptive offset,and adaptive loop filter,were performed separately for each component.Recently,cross-component filters have been studied to improve chroma fidelity by exploiting correlations between the luma and chroma channels.This paper introduces the cross-component filters used in the state-ofthe-art video coding standards,including the cross-component adaptive loop filter and cross-component sample adaptive offset.Crosscomponent filters aim to reduce compression artifacts based on the correlation between different components and provide more accurate pixel reconstruction values.We present their origin,development,and status in the current video coding standards.Finally,we conduct discussions on the further evolution of cross-component filters.
文摘Joint Radar and Communications(JRC)can implement two Radio Frequency(RF)functions using a single of resources,providing significant hardware,power and spectrum savings for wireless systems requiring both functions.Frequency-Hopping(FH)MIMO radar is a popular candidate for JRC because the achieved communication symbol rate can greatly exceed the radar pulse repetition frequency.However,practical transceiver imperfections can cause many existing theoretical designs to fail.In this work,we reveal for the first time the non-trivial impact of hardware imperfections on FH-MIMO JRC and model the impact analytically.We also design new waveforms and correspondingly develop a low-complexity algorithm to jointly estimate the hardware imperfections of unsynchronized receiver.In addition,using low-cost software-defined radios and Commercial Off-The-Shelf(COTS)products,we build the first FH-MIMO JRC experimental platform with simultaneous over-the-air radar and communication validation.Confirmed by simulation and experimental results,the proposed designs achieve high performance for both radar and communications.
基金supported by the National Natural Science Foundation of China(Nos.60976023,61234003)the Special Funds for Major State Basic Research Project of China(No.2011CB932902)
文摘This paper presents a high-speed column-parallel cyclic analog-to-digital converter（ADC） for a CMOS image sensor.A correlated double sampling（CDS） circuit is integrated in the ADC,which avoids a stand-alone CDS circuit block.An offset cancellation technique is also introduced,which reduces the column fixed-pattern noise（FPN） effectively.One single channel ADC with an area less than 0.02 mm^2 was implemented in a 0.13μm CMOS image sensor process.The resolution of the proposed ADC is 10-bit,and the conversion rate is 1.6 MS/s. The measured differential nonlinearity and integral nonlinearity are 0.89 LSB and 6.2 LSB together with CDS, respectively.The power consumption from 3.3 V supply is only 0.66 mW.An array of 48 10-bit column-parallel cyclic ADCs was integrated into an array of CMOS image sensor pixels.The measured results indicated that the ADC circuit is suitable for high-speed CMOS image sensors.
基金supported by the National Natural Science Foundation of China under Grant No.62171174National Key R&D Program of China under Grant No.2023YFC3706605the Open Project of Zhejiang Provincial Key Laboratory of Information Processing,Communication,and Networking.
文摘A learning-based adaptive loop filter is developed for the geometry-based point-cloud compression(G-PCC)standard to reduce attribute compression artifacts.The proposed method first generates multiple most probable sample offsets(MPSOs)as potential compression distortion approximations,and then linearly weights them for artifact mitigation.Therefore,we drive the filtered reconstruction as closely to the uncompressed PCA as possible.To this end,we devise an attribute artifact reduction network(ARNet)consisting of two consecutive processing phases:MPSOs derivation and MPSOs combination.The MPSOs derivation uses a two-stream network to model local neighborhood variations from direct spatial embedding and frequency-dependent embedding,where sparse convolutions are utilized to best aggregate information from sparsely and irregularly distributed points.The MPSOs combination is guided by the least-squares error metric to derive weighting coefficients on the fly to further capture the content dynamics of the input PCAs.ARNet is implemented as an in-loop filtering tool for GPCC,where the linear weighting coefficients are encapsulated into the bitstream with negligible bitrate overhead.The experimental results demonstrate significant improvements over the latest G-PCC both subjectively and objectively.For example,our method offers a 22.12%YUV Bjøntegaard delta rate(BDRate)reduction compared to G-PCC across various commonly used test point clouds.Compared with a recent study showing state-of-the-art performance,our work not only gains 13.23%YUV BD-Rate but also provides a 30×processing speedup.
