scholarly journals 2D+t Wavelet Domain Video Watermarking

2012 ◽  
Vol 2012 ◽  
pp. 1-19 ◽  
Author(s):  
Deepayan Bhowmik ◽  
Charith Abhayaratne
Keyword(s):  
Vector Fields ◽  
Signal To Noise Ratio ◽  
Motion Vector ◽  
Video Data ◽  
Video Watermarking ◽  
Wavelet Domain ◽  
Jpeg 2000 ◽  
Temporal Filtering ◽  
Temporal Decomposition ◽  
Direct Motion

A novel watermarking framework for scalable coded video that improves the robustness against quality scalable compression is presented in this paper. Unlike the conventional spatial-domain (t + 2D) water-marking scheme where the motion compensated temporal filtering (MCTF) is performed on the spatial frame-wise video data to decompose the video, the proposed framework applies the MCTF in the wavelet domain (2D + t) to generate the coefficients to embed the watermark. Robustness performances against scalable content adaptation, such as Motion JPEG 2000, MC-EZBC, or H.264-SVC, are reviewed for various combinations of motion compensated 2D + t + 2D using the proposed framework. The MCTF is improved by modifying the update step to follow the motion trajectory in the hierarchical temporal decomposition by using direct motion vector fields in the update step and implied motion vectors in the prediction step. The results show smaller embedding distortion in terms of both peak signal to noise ratio and flickering metrics compared to frame-by-frame video watermarking while the robustness against scalable compression is improved by using 2D + t over the conventional t + 2D domain video watermarking, particularly for blind watermarking schemes where the motion is estimated from the watermarked video.

scholarly journals Meso- and microscale sea-ice motion in the East Siberian Sea as determined from ERS-1 SAR Data

1999 ◽  
Vol 45 (150) ◽  
pp. 370-383 ◽  
Author(s):  
Kim Morris ◽  
Shusun Li ◽  
Martin Jeffries
Keyword(s):  
Time Series ◽  
Sea Ice ◽  
Large Scale ◽  
Vector Fields ◽  
Lateral Displacement ◽  
Motion Vector ◽  
Sar Interferometry ◽  
East Siberian Sea ◽  
Pack Ice ◽  
Sar Data

Abstract Synthetic aperture radar- (SAR-)derived ice-motion vectors and SAR interferometry were used to study the sea-ice conditions in the region between the coast and 75° N (~ 560 km) in the East Siberian Sea in the vicinity of the Kolyma River. ERS-1 SAR data were acquired between 24 December 1993 and 30 March 1994 during the 3 day repeat Ice Phase of the satellite. The time series of the ice-motion vector fields revealed rapid (3 day) changes in the direction and displacement of the pack ice. Longer-term (≥ 1 month) trends also emerged which were related to changes in large-scale atmospheric circulation. On the basis of this time series, three sea-ice zones were identified: the near-shore, stationary-ice zone; a transitional-ice zone;and the pack-ice zone. Three 3 day interval and one 9 day interval interferometric sets (amplitude, correlation and phase diagrams) were generated for the end of December, the begining of February and mid-March. They revealed that the stationary-ice zone adjacent to the coast is in constant motion, primarily by lateral displacement, bending, tilting and rotation induced by atmospheric/oceanic forcing. The interferogram patterns change through time as the sea ice becomes thicker and a network of cracks becomes established in the ice cover. It was found that the major features in the interferograms were spatially correlated with sea-ice deformation features (cracks and ridges) and major discontinuities in ice thickness.

scholarly journals The determination of high-resolution spatio-temporal glacier motion fields from time-lapse sequences

2017 ◽  
Vol 5 (4) ◽  
pp. 861-879 ◽  
Author(s):  
Ellen Schwalbe ◽  
Hans-Gerd Maas
Keyword(s):  
High Resolution ◽  
Vector Fields ◽  
Motion Vector ◽  
Image Sequence ◽  
Image Sequences ◽  
Glacier Surface ◽  
Sequence Processing ◽  
Image Sequence Processing ◽  
Matching Techniques

Abstract. This paper presents a comprehensive method for the determination of glacier surface motion vector fields at high spatial and temporal resolution. These vector fields can be derived from monocular terrestrial camera image sequences and are a valuable data source for glaciological analysis of the motion behaviour of glaciers. The measurement concepts for the acquisition of image sequences are presented, and an automated monoscopic image sequence processing chain is developed. Motion vector fields can be derived with high precision by applying automatic subpixel-accuracy image matching techniques on grey value patterns in the image sequences. Well-established matching techniques have been adapted to the special characteristics of the glacier data in order to achieve high reliability in automatic image sequence processing, including the handling of moving shadows as well as motion effects induced by small instabilities in the camera set-up. Suitable geo-referencing techniques were developed to transform image measurements into a reference coordinate system.The result of monoscopic image sequence analysis is a dense raster of glacier surface point trajectories for each image sequence. Each translation vector component in these trajectories can be determined with an accuracy of a few centimetres for points at a distance of several kilometres from the camera. Extensive practical validation experiments have shown that motion vector and trajectory fields derived from monocular image sequences can be used for the determination of high-resolution velocity fields of glaciers, including the analysis of tidal effects on glacier movement, the investigation of a glacier's motion behaviour during calving events, the determination of the position and migration of the grounding line and the detection of subglacial channels during glacier lake outburst floods.

scholarly journals COMPARATIVE ANALYSIS OF COMPACT METHODS REPRESENTATIONS OF GRAPHIC INFORMATION

2021 ◽  
Vol 1 (37) ◽  
pp. 130-143
Author(s):  
O. Gertsiy
Keyword(s):  
Comparative Analysis ◽  
Communication Systems ◽  
Video Data ◽  
Transport Infrastructure ◽  
Practical Significance ◽  
Jpeg 2000 ◽  
Advantages And Disadvantages ◽  
Graphic Information ◽  
The Cost ◽  
And Storage

The main characteristics of graphic information compression methods with losses and without losses (RLE, LZW, Huffman's method, DEFLATE, JBIG, JPEG, JPEG 2000, Lossless JPEG, fractal and Wawelet) are analyzed in the article. Effective transmission and storage of images in railway communication systems is an important task now. Because large images require large storage resources. This task has become very important in recent years, as the problems of information transmission by telecommunication channels of the transport infrastructure have become urgent. There is also a great need for video conferencing, where the task is to effectively compress video data - because the greater the amount of data, the greater the cost of transmitting information, respectively. Therefore, the use of image compression methods that reduce the file size is the solution to this task. The study highlights the advantages and disadvantages of compression methods. The comparative analysis the basic possibilities of compression methods of graphic information is carried out. The relevance lies in the efficient transfer and storage of graphical information, as big data requires large resources for storage. The practical significance lies in solving the problem of effectively reducing the data size by applying known compression methods.

Performance Evaluation of Different Cost Functions in Motion Vector Estimation

2014 ◽  
Vol 5 (1) ◽  
pp. 45-65 ◽  
Author(s):  
Suvojit Acharjee ◽  
Sayan Chakraborty ◽  
Wahiba Ben Abdessalem Karaa ◽  
Ahmad Taher Azar ◽  
Nilanjan Dey
Keyword(s):  
Video Compression ◽  
Motion Vector ◽  
Video Data ◽  
Cost Functions ◽  
Absolute Difference ◽  
Surveillance Video ◽  
Mean Absolute Difference ◽  
Vector Estimation ◽  
The Difference ◽  
Temporal Redundancy

Video is an important medium in terms of information sharing in this present era. The tremendous growth of video use can be seen in the traditional multimedia application as well as in many other applications like medical videos, surveillance video etc. Raw video data is usually large in size, which demands for video compression. In different video compressing schemes, motion vector is a very important step to remove the temporal redundancy. A frame is first divided into small blocks and then motion vector for each block is computed. The difference between two blocks is evaluated by different cost functions (i.e. mean absolute difference (MAD), mean square error (MSE) etc).In this paper the performance of different cost functions was evaluated and also the most suitable cost function for motion vector estimation was found.

scholarly journals Nowcasting Surface Solar Irradiance with AMESIS via Motion Vector Fields of MSG-SEVIRI Data

2018 ◽  
Vol 10 (6) ◽  
pp. 845 ◽  
Author(s):  
Donatello Gallucci ◽  
Filomena Romano ◽  
Angela Cersosimo ◽  
Domenico Cimini ◽  
Francesco Di Paola ◽  
...  
Keyword(s):  
Solar Irradiance ◽  
Vector Fields ◽  
Motion Vector

scholarly journals A Robust H.264/AVC Video Watermarking Scheme with Drift Compensation

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Xinghao Jiang ◽  
Tanfeng Sun ◽  
Yue Zhou ◽  
Wan Wang ◽  
Yun-Qing Shi
Keyword(s):  
Motion Vector ◽  
Video Watermarking ◽  
Estimation Algorithms ◽  
Low Bit Rate ◽  
Copyright Information ◽  
Drift Compensation ◽  
Visual Impact ◽  
Partition Size ◽  
Distortion Drift ◽  
Watermarking Scheme

A robust H.264/AVC video watermarking scheme for copyright protection with self-adaptive drift compensation is proposed. In our scheme, motion vector residuals of macroblocks with the smallest partition size are selected to hide copyright information in order to hold visual impact and distortion drift to a minimum. Drift compensation is also implemented to reduce the influence of watermark to the most extent. Besides, discrete cosine transform (DCT) with energy compact property is applied to the motion vector residual group, which can ensure robustness against intentional attacks. According to the experimental results, this scheme gains excellent imperceptibility and low bit-rate increase. Malicious attacks with different quantization parameters (QPs) or motion estimation algorithms can be resisted efficiently, with 80% accuracy on average after lossy compression.

Motion vector fields based video coding

2015 ◽  
Author(s):  
Amin Zheng ◽  
Yuan Yuan ◽  
Hong Zhang ◽  
Haitao Yang ◽  
Pengfei Wan ◽  
...  
Keyword(s):  
Video Coding ◽  
Vector Fields ◽  
Motion Vector
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