scholarly journals HFR Projector Camera Based Visible Light Communication System for Real-Time Video Streaming

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5368
Author(s):  
Atul Sharma ◽  
Sushil Raut ◽  
Kohei Shimasaki ◽  
Taku Senoo ◽  
Idaku Ishii
Keyword(s):  
Visible Light ◽  
Real Time ◽  
Video Streaming ◽  
Video Sequence ◽  
Vision System ◽  
Visible Light Communication ◽  
Gray Code ◽  
Frame Rate ◽  
Video Sequences ◽  
Color Video

This study develops a projector–camera-based visible light communication (VLC) system for real-time broadband video streaming, in which a high frame rate (HFR) projector can encode and project a color input video sequence into binary image patterns modulated at thousands of frames per second and an HFR vision system can capture and decode these binary patterns into the input color video sequence with real-time video processing. For maximum utilization of the high-throughput transmission ability of the HFR projector, we introduce a projector–camera VLC protocol, wherein a multi-level color video sequence is binary-modulated with a gray code for encoding and decoding instead of pure-code-based binary modulation. Gray code encoding is introduced to address the ambiguity with mismatched pixel alignments along the gradients between the projector and vision system. Our proposed VLC system consists of an HFR projector, which can project 590 × 1060 binary images at 1041 fps via HDMI streaming and a monochrome HFR camera system, which can capture and process 12-bit 512 × 512 images in real time at 3125 fps; it can simultaneously decode and reconstruct 24-bit RGB video sequences at 31 fps, including an error correction process. The effectiveness of the proposed VLC system was verified via several experiments by streaming offline and live video sequences.

scholarly journals Visual-Feedback-Based Frame-by-Frame Synchronization for 3000 fps Projector–Camera Visual Light Communication

Electronics ◽  
2021 ◽  
Vol 10 (14) ◽  
pp. 1631
Author(s):  
Atul Sharma ◽  
Sushil Raut ◽  
Kohei Shimasaki ◽  
Taku Senoo ◽  
Idaku Ishii
Keyword(s):  
Real Time ◽  
Visual Feedback ◽  
Video Sequence ◽  
Clock Cycle ◽  
Frame Rate ◽  
Video Sequences ◽  
Frame Synchronization ◽  
Bandwidth Utilization ◽  
Long Distance ◽  
Synchronization Algorithm

This paper proposes a novel method for synchronizing a high frame-rate (HFR) camera with an HFR projector, using a visual feedback-based synchronization algorithm for streaming video sequences in real time on a visible-light communication (VLC)-based system. The frame rates of the camera and projector are equal, and their phases are synchronized. A visual feedback-based synchronization algorithm is used to mitigate the complexities and stabilization issues of wire-based triggering for long-distance systems. The HFR projector projects a binary pattern modulated at 3000 fps. The HFR camera system operates at 3000 fps, which can capture and generate a delay signal to be given to the next camera clock cycle so that it matches the phase of the HFR projector. To test the synchronization performance, we used an HFR projector–camera-based VLC system in which the proposed synchronization algorithm provides maximum bandwidth utilization for the high-throughput transmission ability of the system and reduces data redundancy efficiently. The transmitter of the VLC system encodes the input video sequence into gray code, which is projected via high-definition multimedia interface streaming in the form of binary images 590 × 1060. At the receiver, a monochrome HFR camera can simultaneously capture and decode 12-bit 512 × 512 images in real time and reconstruct a color video sequence at 60 fps. The efficiency of the visual feedback-based synchronization algorithm is evaluated by streaming offline and live video sequences, using a VLC system with single and dual projectors, providing a multiple-projector-based system. The results show that the 3000 fps camera was successfully synchronized with a 3000 fps single-projector and a 1500 fps dual-projector system. It was confirmed that the synchronization algorithm can also be applied to VLC systems, autonomous vehicles, and surveillance applications.

750 Mb/s monochromatic LED-based real-time visible light communication system employing a low-complexity cascaded post-equalizer

2016 ◽  
Vol 14 (12) ◽  
pp. 120604-120608 ◽  
Author(s):  
Jiabin Luo Jiabin Luo ◽  
Yi Tang Yi Tang ◽  
Huiping Jia Huiping Jia ◽  
Qingwei Zhu Qingwei Zhu ◽  
and Wei Xue唯 薛 and Wei Xue唯 薛
Keyword(s):  
Visible Light ◽  
Real Time ◽  
Communication System ◽  
Visible Light Communication ◽  
Low Complexity

scholarly journals Real-time white-light phosphor-LED visible light communication (VLC) with compact size

2013 ◽  
Vol 21 (22) ◽  
pp. 26192 ◽  
Author(s):  
Chien-Hung Yeh ◽  
Yen-Liang Liu ◽  
Chi-Wai Chow
Keyword(s):  
Visible Light ◽  
Real Time ◽  
White Light ◽  
Visible Light Communication ◽  
Compact Size

Real-Time Image Mosaicing System Using a High-Frame-Rate Video Sequence

2015 ◽  
Vol 27 (1) ◽  
pp. 12-23 ◽  
Author(s):  
Qingyi Gu ◽  
◽  
Sushil Raut ◽  
Ken-ichi Okumura ◽  
Tadayoshi Aoyama ◽  
...  
Keyword(s):  
Real Time ◽  
High Speed ◽  
Video Sequence ◽  
Frame Rate ◽  
Image Mosaicing ◽  
Current Frame ◽  
High Frame Rate ◽  
Harris Corner ◽  
Real Time Image ◽  
Time Image

<div class=""abs_img""><img src=""[disp_template_path]/JRM/abst-image/00270001/02.jpg"" width=""300"" />Synthesized panoramic images</div> In this paper, we propose a real-time image mosaicing system that uses a high-frame-rate video sequence. Our proposed system can mosaic 512 × 512 color images captured at 500 fps as a single synthesized panoramic image in real time by stitching the images based on their estimated frame-to-frame changes in displacement and orientation. In the system, feature point extraction is accelerated by implementing a parallel processing circuit module for Harris corner detection, and hundreds of selected feature points in the current frame can be simultaneously corresponded with those in their neighbor ranges in the previous frame, assuming that frame-to-frame image displacement becomes smaller in high-speed vision. The efficacy of our system for improved feature-based real-time image mosaicing at 500 fps was verified by implementing it on a field-programmable gate array (FPGA)-based high-speed vision platform and conducting several experiments: (1) capturing an indoor scene using a camera mounted on a fast-moving two-degrees-of-freedom active vision, (2) capturing an outdoor scene using a hand-held camera that was rapidly moved in a periodic fashion by hand. </span>

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