for Mobile Augmented Reality David Chen 1 , Mina Makar 1,2 , Andre - - PowerPoint PPT Presentation

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for Mobile Augmented Reality David Chen 1 , Mina Makar 1,2 , Andre - - PowerPoint PPT Presentation

Interframe Coding of Global Image Signatures for Mobile Augmented Reality David Chen 1 , Mina Makar 1,2 , Andre Araujo 1 , Bernd Girod 1 1 Department of Electrical Engineering, Stanford University 2 Qualcomm Inc. 1 Chen et al. , Interframe Coding


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Chen et al., Interframe Coding of Global Image Signatures for Mobile Augmented Reality

Interframe Coding of Global Image Signatures for Mobile Augmented Reality

David Chen1, Mina Makar1,2, Andre Araujo1, Bernd Girod1

1Department of Electrical Engineering, Stanford University 2Qualcomm Inc.

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Chen et al., Interframe Coding of Global Image Signatures for Mobile Augmented Reality

Samsung Galaxy S3 Smartphone

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Chen et al., Interframe Coding of Global Image Signatures for Mobile Augmented Reality

On-Device Image Matching System

Extract Local Features Generate Global Signature Match with Database Global Signatures Perform Geometric Verification Local Database

… … … …

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Chen et al., Interframe Coding of Global Image Signatures for Mobile Augmented Reality

Hybrid Image Matching System

Extract Local Features Generate Global Signature Match with Database Global Signatures Perform Geometric Verification Local Database

Wireless Network

Remote Database Match with Database Global Signatures Send compact interframe coded stream of global signatures in uplink Send labels, local features, and global signatures for top-ranked database candidates in downlink

0.51 0.62 0.50 0.49

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Chen et al., Interframe Coding of Global Image Signatures for Mobile Augmented Reality

Outline

  • Related work on feature compression
  • Interframe coding of global signatures

– Selective codeword propagation – Selective frame propagation – Selective frame propagation + local search – Global signature embedding

  • Coding and retrieval results
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Chen et al., Interframe Coding of Global Image Signatures for Mobile Augmented Reality

Related Work on Feature Compression

Intraframe Coding Interframe Coding Global Image Signatures Local Image Features

Random projections [Yeo, 2008] Transform coding [Chandrasekhar, 2009] Location histogram coding [Tsai, 2009] CHoG [Chandrasekhar, 2009] Bag of hash bits [He, 2011] Trace transform [Brasnett, 2007] Tree histogram coding [Chen, 2009] Residual vectors [Perronnin, 2010] [Jegou, 2010] [Chen, 2011] Temporally coherent keypoint detector [Makar, 2012] Descriptor and location predictive coding [Makar, 2012] [Baroffio, 2014]

Our Current Work

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Chen et al., Interframe Coding of Global Image Signatures for Mobile Augmented Reality

Forward Propagation (FP) Frame Detection (D) Frame

Temporally Coherent Keypoint Detection

Makar et al., 2012

time

t

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Chen et al., Interframe Coding of Global Image Signatures for Mobile Augmented Reality

Generating Feature Residuals

k = 3

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Chen et al., Interframe Coding of Global Image Signatures for Mobile Augmented Reality

Generating Feature Residuals

k = 3

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Chen et al., Interframe Coding of Global Image Signatures for Mobile Augmented Reality

Residual Enhanced Visual Vector (REVV)

Chen et al., 2011

Extract Local Features Quantize Feature Descriptors k codewords Normalize Feature Residuals Query Image Regularize with Power Law Perform Cell-Specific LDA Binarize Components from Sign Compute Weighted Correlations Database Signatures Ranked List

0.74 0.73 0.72 0.70 0.63 0.62

Reduce Dimensions by PCA Normalize Correlation Scores

  • 1

+1

5 10 15 20 25 30 0.05 0.1 0.15 0.2 Hamming Distance Probability Matching Images Non-matching Images 5 10 15 20 25 30 0.2 0.4 0.6 0.8 1 Hamming Distance Weights
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Continuous stream of REVV signatures

Interframe Coding of REVV

R1 S1 Extract REVV Extract REVV Extract REVV Extract REVV R2 Predictively Encode S2 Rn+1 Sn+1 Mobile Device Database REVV Signatures Compute Weighted Correlations Wireless Network Server Decode REVV Signatures Previous REVV Signatures Recognition results + Features for top candidates D-Frame D-Frame FP-Frame FP-Frame

Keypoints Keypoints Keypoints

S1

Rn Predictively Encode Sn S2 Sn-1

… …

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Chen et al., Interframe Coding of Global Image Signatures for Mobile Augmented Reality

Interframe Coding of REVV

R1 S1 Extract REVV Extract REVV Extract REVV Extract REVV R2 Predictively Encode S2 Rn+1 Sn+1 D-Frame D-Frame FP-Frame FP-Frame

Keypoints Keypoints Keypoints

S1

Rn Predictively Encode Sn S2 Sn-1

… …

Ut,1 = 1 Ut,2 = 1 Ut,4 = 1 Ut,6 = 1 Ut,k = 1 … Rt,1 Rt,2 Rt,4 Rt,6 Rt,k Ut,3 = 0 Ut,5 = 0 Vt,1 = 1 Vt,2 = 1 Vt,4 = 1 Vt,6 = 1 Vt,k = 1 … St,1 St,2 St,4 St,6 St,k Vt,3 = 0 Vt,5 = 0

Extracted REVV Signature Transmitted REVV Signature

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Chen et al., Interframe Coding of Global Image Signatures for Mobile Augmented Reality

Selective Codeword Propagation (SCP)

Ut,1 = 1 Ut,2 = 1 Ut,4 = 1 Ut,8 = 1 Rt,1 Rt,2 Ut,3 = 0 Ut,5 = 1 Ut,6 = 1 Ut,7 = 0 … Rt,4 Rt,5 Rt,6 Rt,8 Frame t D-Frame Extracted Wireless Network Mobile Device Server Vt,1 = 1 Vt,2 = 1 Vt,4 = 1 Vt,8 = 1 St,1 St,2 Vt,3 = 0 Vt,5 = 1 Vt,6 = 1 Vt,7 = 0 St,4 St,5 St,6 St,8 Frame t D-Frame Received … Ut+1,1 = 1 Ut+1,2 = 1 Ut+1,3 = 1 Ut+1,4 = 1 Ut+1,6 = 1 Ut+1,8 = 1 Ut+1,7 = 0 Ut+1,5 = 0 Frame t+1 FP-Frame Extracted Rt+1,1 Rt+1,2 Rt+1,4 Rt+1,3 Rt+1,6 Rt+1,8 Frame t+1 FP-Frame Sent Vt+1,1 = 1 Vt+1,2 = 1 Vt+1,4 = 1 Vt+1,8 = 1 St+1,1 St+1,2 Vt+1,3 = 0 Vt+1,5 = 0 Vt+1,6 = 1 Vt+1,7 = 0 … St+1,4 St+1,6 St+1,8 AND AND AND AND AND AND AND AND Frame t+1 FP-Frame Received Vt+1,1 = 1 Vt+1,2 = 1 Vt+1,4 = 1 Vt+1,8 = 1 St+1,1 St+1,2 Vt+1,3 = 0 Vt+1,5 = 0 Vt+1,6 = 1 Vt+1,7 = 0 … St+1,4 St+1,6 St+1,8 …

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Selective Frame Propagation (SFP)

Ut,1 = 1 Ut,2 = 1 Ut,4 = 1 Ut,8 = 1 Rt,1 Rt,2 Ut,3 = 0 Ut,5 = 1 Ut,6 = 1 Ut,7 = 0 … Rt,4 Rt,5 Rt,6 Rt,8 Frame t D-Frame Extracted Mobile Device Ut+1,1 = 1 Ut+1,2 = 1 Ut+1,3 = 1 Ut+1,4 = 1 Ut+1,6 = 1 Ut+1,8 = 1 Ut+1,7 = 0 Ut+1,5 = 0 Frame t+1 FP-Frame Extracted Rt+1,1 Rt+1,2 Rt+1,4 Rt+1,3 Rt+1,6 Rt+1,8

 

 

, 1, 1, 1 1

, 1 AND ,

k k k t j t j t j j j

r t t U U U

   

 

SCP Encoding Vt+1,1 = 1 Vt+1,2 = 1 Vt+1,4 = 1 Vt+1,8 = 1 St+1,1 St+1,2 Vt+1,3 = 0 Vt+1,5 = 0 Vt+1,6 = 1 Vt+1,7 = 0 … St+1,4 St+1,6 St+1,8

Interframe Codeword Similarity rk > tr ? Yes No

SFP Encoding … Vt+1,1 = 1 Vt+1,2 = 1 Vt+1,4 = 1 Vt+1,8 = 1 St+1,1 St+1,2 Vt+1,3 = 0 Vt+1,5 = 0 Vt+1,6 = 1 Vt+1,7 = 0 St+1,4 St+1,6 St+1,8 St+1,5 …

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Chen et al., Interframe Coding of Global Image Signatures for Mobile Augmented Reality

SFP + Local Search (SFP + LS)

Local Database Remote Database Wireless Network Mobile Device Server

Ngeo ³ tgeo

Terminate query locally

  • n mobile device

Send REVV stream to server by SFP coding

Ngeo < tgeo

Send local features and REVV signatures for top ranked database candidates to mobile device Number of inliers in geometric verification

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Chen et al., Interframe Coding of Global Image Signatures for Mobile Augmented Reality

Embedded Global Signatures

Codeword 1 Codeword 2 Codeword 3 Codeword 4 Codeword 5 Codeword 6 Codeword 7 Codeword 8

Level 1  Highest Bitrate Level 3  Lowest Bitrate Level 2  Medium Bitrate

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Chen et al., Interframe Coding of Global Image Signatures for Mobile Augmented Reality

Outline

  • Related work on feature compression
  • Interframe coding of global signatures

– Selective codeword propagation – Selective frame propagation – Selective frame propagation + local search – Global signature embedding

  • Coding and retrieval results
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Analysis of Retrieval Performance

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Chen et al., Interframe Coding of Global Image Signatures for Mobile Augmented Reality

Mobile Augmented Reality

Stanford Streaming MAR Dataset

32 VGA-resolution query videos recorded with a camera phone Database of 23 labeled objects + 1M distractor images

[Makar et al., 2013]

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Chen et al., Interframe Coding of Global Image Signatures for Mobile Augmented Reality

Experimental Setup

  • Interframe coding parameters

– ND-Frames = 1 and NFP-Frames = 29 for frame rate of 30 fps – Interframe codeword similarity threshold: tr = 0.9 – RANSAC threshold: tgeo = 25 feature matches

  • REVV signature parameters

– 250 SIFT features extracted for every D-Frame – Dimensionality reduction to dLDA = 32 – Codebook of k = 190 codewords

  • Retrieval accuracy vs. uplink bitrate comparison
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Retrieval Accuracy vs. Uplink Bitrate

Embedding: Level 1 Embedding: Level 2 Embedding: Level 3 14x 24x 88x < 2 kbps

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Chen et al., Interframe Coding of Global Image Signatures for Mobile Augmented Reality

Conclusions

  • Developed efficient methods for interframe coding of a

continuous stream of global REVV signatures

– Adapts bitrate in response to current viewfinder contents – Combines advantages of local and remote database search – Performs local database update at same time as query expansion

  • Analyzed how retrieval accuracy varies with bitrate

– Models distributions of REVV correlation scores – Quantifies bitrate savings for all coding methods

  • Achieved substantial bitrate savings

– Reduces uplink bitrate by almost 2 orders of magnitude – Requires only a small downlink bitrate

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Thank You

dmchen@stanford.edu