Low-precision logarithmic number system (LNS) arithmetic can reduce the power consumption for MPEG decoding compared to conventional fixed-point techniques. Although this introduces small numeric errors, which violate...
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Low-precision logarithmic number system (LNS) arithmetic can reduce the power consumption for MPEG decoding compared to conventional fixed-point techniques. Although this introduces small numeric errors, which violate the IEEE-1180 standard for the inverse discrete cosine transform (IDCT), the visual effects of such error may be tolerable for portable battery-powered devices, like videophones, that have limited-resolution displays. The MPEG standard achieves video compression by quantization of the data fed to the IDCT. The MPEG decoder must multiply this data by dequantization factors. Such multiplication, by itself, is trivial with LNS since adding logarithms is equivalent to multiplication. The IEEE-1180 standard suggests oddification, where fixed-point data is forced to become odd after dequantization to minimize IDCT mismatch between the encoder and the decoder. Oddification poses an implementation problem for data in LNS format. This paper suggests that the visual effect of LNS without oddification is nearly indistinguishable from LNS with oddification, meaning that the benefits of LNS in MPEG are even greater than previously expected.
Due to huge growth in multimedia and technology, it is very important to go through the point of interest rather than accessing the entire video. For efficient indexing and retrieving the interest points, content base...
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ISBN:
(纸本)9781479960866
Due to huge growth in multimedia and technology, it is very important to go through the point of interest rather than accessing the entire video. For efficient indexing and retrieving the interest points, content based video retrieval is used. The first step toward CBVR is shot boundary detection. It is necessary to partition the video into shots for easy indexing and retrieval of video. Therefore, segmentation plays an important role in digital media processing, pattern recognition, and computer vision. In this paper, we present different approaches to shot boundary detection problem.
Digital images have been widely used in many applications. However, digital image forgery has already become a serious problem due to the rapid development of powerful image editing software. One of the most commonly ...
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Digital images have been widely used in many applications. However, digital image forgery has already become a serious problem due to the rapid development of powerful image editing software. One of the most commonly used forgery techniques is Copy-move forgery that copies a region of an image and pastes it on the other region in the same image. In recent years, most techniques aim to detect such tampering. Different feature extraction methods have been used to improve the capability of the detection algorithm. In this work, we used two dimensional Fourier transform (2D-FT) to extract some features from the blocks. Predetermined number of Fourier coefficients hold information about the blocks. At the final stage, the similarity search between the adjacent feature vectors is performed to determine the forgery. Experimental results show that proposed method can detect the duplicated regions with high accuracy rate even if the image is distorted with blurring mask or it is compressed with different JPEG quality factors. The dimension of feature vector is also lower than the other methods in the literature. Thus, the method ensures the lower feature vector with high accuracy rates. The proposed method also detects multiple copy move forgery as shown in the results.
The compression and decompression of MPEG-2 video play a major role in entertainment delivery devices. This paper investigates software MPEG-2 video decoding on a multiprocessing microprocessor, MAJC-5200. MAJC (micro...
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The compression and decompression of MPEG-2 video play a major role in entertainment delivery devices. This paper investigates software MPEG-2 video decoding on a multiprocessing microprocessor, MAJC-5200. MAJC (microprocessor architecture for Java computing), is a very long instruction word (VLIW) processor with an instruction set geared towards multimedia computing. We describe the microprocessor and show that less than 50% of a single CPU out of the available true processors is sufficient for decoding 4 Mb/s video sequences.
In this paper, we propose an effective design and implementation of a versatile embedded multimedia live streaming decoder system based on TI's DM814x processor, which can not only decode video live streams of var...
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ISBN:
(纸本)9781479969579
In this paper, we propose an effective design and implementation of a versatile embedded multimedia live streaming decoder system based on TI's DM814x processor, which can not only decode video live streams of various video codecs(H.264, MPEG-4, etc.), audio live streams of various audio codecs(AAC, MP3, G.711, etc.), but also demultiplex (demux) MPEG-2 TS, decode video stream and audio streams inside, all streams carried over RTP after the stream servers are contacted by RTSP URLs. Those decoded live raw streams are displayed out through the attached HDMI, HD-SDI, NTSC, and line-out interface of the embedded decoder. The S/W architecture, protocol handling and buffer management of the proposed embedded decoder system are studied carefully and explained here in some detail. Currently, our implementation is observed to work properly. However, synchronization among video, audio, and associated (meta) data at the decoding and displaying are not precisely achieved and still are under development, whose results will be reported later.
Quantisation is used in video coders such as MPEG in association with rate control scheme to regulate the data rate of compressed video bit stream entering the transmission buffer. When the transmission data rate is l...
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Quantisation is used in video coders such as MPEG in association with rate control scheme to regulate the data rate of compressed video bit stream entering the transmission buffer. When the transmission data rate is limited the quantiser has a crucial effect on video data rate and video quality. The quantiser step size is generally determined by a linear non-adaptive method with respect to the buffer occupancy. In this paper, we investigate in the framework of rate-distortion theory two adaptive nonlinear quantiser control functions, sigmoidal and unimodal, which achieve superior video rate control performance while maintaining similar video quality to the linear case. Their performance for video rate fluctuation has also been analysed in both analytic and experimental ways.
Modern digital image processing requires powerful data compression algorithms to allow the data to be efficiently transferred from the host to end users (and back again). A typical 512times512 grayscale image of uncom...
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Modern digital image processing requires powerful data compression algorithms to allow the data to be efficiently transferred from the host to end users (and back again). A typical 512times512 grayscale image of uncompressed data requires more than quarter of a million bytes. Current image compression standards like JPEG2000 and the FBI WSQ (wavelet scalar quantization) use wavelet transforms with quantization to compress still images, which reconstruct with high accuracy. This paper considers a number of popular 9/7 wavelet transform architectures. High level software models are developed for these transforms to validate their effectiveness. These software models are modified and evaluated as reversible integer wavelet lifting transforms. Further, using a virtual hardware design targeted to reconfigurable FPGA technology these transforms are implemented into a 2D discrete wavelet transform (DWT) image processor with DDR SDRAM operating at core speeds of 200+ MHz. Finally, our Matlab and Maple models perform the validation of wavelet lifting transforms
The ability to construct intra-coded frame from motion-compensated inter-frame coded directly in the compressed domain is important for efficient video manipulation and composition. In the context of motion-compensate...
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ISBN:
(纸本)0780351487
The ability to construct intra-coded frame from motion-compensated inter-frame coded directly in the compressed domain is important for efficient video manipulation and composition. In the context of motion-compensated DCT-based coding of video as in MPEG video, this problem of DCT domain inverse motion compensation has been studied by Chang and Messerschmitt (1995) and fast algorithm based on factorization of the DCT matrix is proposed by Merhav and Bhaskaran (see IEEE International Conference on Acoustics, Speech, and Signal Processing Conference Proceedings, vol.4, p.2307-10, 1996). These schemes, however, treat each 8/spl times/8 block as a fundamental unit, and do not take into account the fact that in MPEG, a macrolock consists of several such blocks. In this paper, we show how shared information within a macroblock such as motion vector and common blocks can be exploited to yield substantial speedup in computation. Compared to the brute-force approach of Chang et al., our algorithms yield about a 44% improvement. Our technique is independent of the underlying computational or processor model, and thus can be implemented on top of any optimized solution. We demonstrate an improvement by about 19% and 13.5% in the worst case on top of the optimized solutions presented by Merhav and Bhaskaran and by Assuncao and Ghanbari (see ICASSP 1997, p.2633-36, 1997).
The use of video streaming for communication is becoming very popular among social and industrial applications such as video calling Skype, `we chat', security system, surveillance system etc. This paper presents ...
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The use of video streaming for communication is becoming very popular among social and industrial applications such as video calling Skype, `we chat', security system, surveillance system etc. This paper presents the analysis & prototype design of system for wireless video streaming in ISM band which make the system very low power and of much lower cost for perimeter control. Conventional rate policing such as generic cell rate algorithm is inadequate to sufficiently regulate transmission of data sources over Zigbee limited by bandwidth. Hence, it is very difficult to transmit JPEG pictures over Zigbee channel. A segment entitled traffic is introduced to prevent excessive overflow of JPEG pictures data over the Zigbee channel. We are proposing a system which will capture pictures through Vision Sensor (Serial JPEG camera - RS232) and transmit through XBee, 2.4GHz(ISM) as RF Transceiver and can be deployed in any highly sensitive defense area for perimeter control.
We describe the results of a series of psychophysical experiments that investigated the relationships among defect visibility, content importance, and perceived impairment in digital video. Various types of controlled...
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We describe the results of a series of psychophysical experiments that investigated the relationships among defect visibility, content importance, and perceived impairment in digital video. Various types of controlled defects were inserted into normal video and shown to our test subjects. The defects varied in their strength, location, appearance, size, and duration. We measured three specific subjective quantities: the defect detection probability, the perceived impairment, and the content importance. Impairment was found to be tightly related to defect visibility but only weakly related to content importance.
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