Byeong-Doo Choi

Real-Time System for Counting the Number of Passing People Using a Single Camera

In this paper, we propose a real-time people counting system with a single camera for security inside the building. The camera is hung from the ceiling of the door so that the image data of the passing people are not fully overlapped. The implemented system recognizes people movement along various directions. To track people even when their images are partially overlapped, the proposed system analyzes the captured image and estimates important feature information. Then each bounding box enclosing each person in the tracking region are tracked. The convex hull of each individual obtained by the proposed algorithm provides more accurate tracking information. Through extensive tests in various environments, the proposed system exhibits the correct people counting results of over 96%.

Remote control system using real-time MPEG-4 streaming technology for mobile robot

This paper presents a mobile robot system which not only achieves real-time compression and transmission of both MPEG-4 video and G.723 audio, but also controls the movement of the robot with a pan-tilt camera and robot arm via the Internet using WLAN.

Real-Time Inspection System for Printed Circuit Boards

The PCB inspection system presented in this paper can detect defects including the breaks in the wires and short circuit and is significantly faster when compared to the existing techniques. The proposed inspection method is based on referential matching between the stored reference image and the test (observed) image. Block matching is performed to solve the misalignment in referential matching. In order to reduce the computational complexity, we implement the proposed algorithm using the single instruction multiple data (SIMD) instructions, so called SSE2.

Real-time DSP implementation of motion-JPEG2000 using overlapped block transferring and parallel-pass methods

This paper presents a real-time implementation of Motion-JPEG2000 encoder using a fixed-point DSP chip. Among several modules in JPEG2000 encoder, the lifting algorithm for discrete wavelet transform (DWT) and the embedded block coding with optimized truncation (EBCOT) comprise more than 85% of the encoding complexity. Thus, it is very important to design and optimize these two modules in order to increase the performance of the hardware implementation. First we propose an overlapped block transferring (OBT) method that can significantly improve the performance of the lifting algorithm for DWT by increasing the cache hit rate. We show that the execution time of the lifting scheme can be further reduced by programming the DSP software using the single instruction multiple data (SIMD) instructions and the super scalar pipeline structure. Moreover, we introduce a parallel-pass method for fast implementation of EBCOT. This method reduces the processing time of EBCOT by processing the three coding passes of the same bit-plane in parallel. Experimental results show that our developed Motion-JPEG2000 DSP system meets the common requirement of the real-time video coding [30 frames/s (fps)] and is proven to be a practical and efficient DSP solution.

Fast motion estimation and intermode selection for H.264

H.264/AVC provides various useful features such as improved coding efficiency and error robustness. These features enable mobile devices to adopt H.264 standard to achieve effective video communications. However, the encoder complexity is greatly increased mainly due to motion estimation (ME) and mode decision. In this paper, we propose a new scheme to jointly optimize intermode selection and ME using the multiresolution analysis. Experimental results show that the proposed method is over 3 times faster than other existing methods while maintaining the coding efficiency.

Channel Adaptive Error Resilience Scheme for Video Transmission over Mobile WiMAX

Video transmission over mobile worldwide interoperability for microwave access (WiMAX) can be serverly degraded due to the effect of fading and handoff. In this paper, we propose a channel adaptive error resilience scheme for video transmission over mobile WiMAX. When the channel condition begins to trigger handoff, the current frame is stored in the long-term memory for the forward error correction, and the following frames are encoded by using double motion vectors (MVs) in the sense of multi-hypothesis motion compensation. Even if a whole frame is lost, we can reconstruct the following frames using the stored frame in the long-term memory. However, the error propagation still remains in this forward error resilience method. To refresh the erroneous frames to the decoder, the encoder utilizes the channel adaptive refreshing (CAR). In the CAR, the channel rate is first predicted using channel parameter, a carrier to interference and noise ratio (CINR), and the encoder adaptively determines the number of blocks to be encoded in the intra mode based on the feedback information. Performance evaluations are presented to demonstrate the effectiveness of the proposed method.

DSP implementation of real-time JPEG2000 encoder using overlapped block transferring and pipelined processing

This paper presents a DSP implementation of real-time JPEG 2000 encoder system Among several modules in JPEG 2000 encoder, the lifting algorithm for discrete wavelet transform (DWT) and the embedded block coding with optimized truncation (EBCOT) comprise more than 85% of the encoding complexity Thus, it is very important to design and optimize these two modules in order to increase the encoding performance First, we propose a overlapped block transferring (OBT) method that can significantly improve the performance of the lifting algorithm for DWT by increasing the cache hit rate Next, we introduce a pipelined processing of passes (PPP) method for fast implementation of EBCOT Tier-1 This method reduces the processing time of EBCOT Tier-1 by processing the three coding passes of the same bit-plane like pipeline Moreover, we propose a computationally efficient method of EBCOT Tier-2 to predict the truncation point by using the temporal redundancy in the image sequence Experimental results show that our developed Motion-JPEG 2000 DSP system meets the common requirement of the real-time video coding [30 frames/s (fps)] and is proven to be a practical and efficient DSP solution.

High-Performance Motion-JPEG2000 encoder using overlapped block transferring and pipelined processing

This paper presents effective DSP implementation strategies for real-time JPEG2000 encoder system, an overlapped block transferring (OBT) for DWT and a pipelined processing of passes (PPP) for EBCOT Tier-1. The proposed OBT method can significantly improve the performance of the lifting algorithm for DWT by increasing the cache hit rate. Moreover the PPP method reduces the processing time of EBCOT Tier-1 by pipelined processing of the three coding passes of the same bit-plane. Experimental results show that Motion-JPEG2000 DSP system meets the common requirement of the real-time video coding [30 frames/s (fps)] and is proven to be a practical and efficient DSP solution.