Description: 探讨了基于zigzag置乱的MPEG4视频数据加密技术，指出了这种方案在安全性方面的不足，提出了改进方
案。改进的方案中AC系数用不同的置乱表置乱，DC系数用高强度的加密算法AES加密。最后给出了改进后的加密效
果，并且从加密速度，安全性和码流变化三个指标衡量了该方案的应用价值。 -Discussion based on the zigzag Scrambling MPEG4 video data encryption technology, pointing out that such a program in the security deficiencies, suggestions to improve the program. Improvement program with a different AC coefficient table Scrambling Scrambling, DC coefficient of high-strength encryption algorithm AES encryption. Finally, the effect of the improved encryption, and from the encryption speed, safety and code changes in the three indicators to measure the flow of the program application value. Platform: |
Size: 165888 |
Author:吴笛 |
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Description: 已知两个不同图像块亮度数据如下：
（1）分析DCT原理，采用DCT方法，编程并计算相应的DCT系数，分析系数分布特点。
（2）依据视觉特性分析量化表步长的分布特点，完成DCT系数量化。
（3）采用Z形扫描，实现输出数据的统计编码，形成Video stream。
（4）采用IDCT重建图像亮度数据，计算SAD大小，分析产生误差的原因及采用DCT进行数据压缩的原理。（ ）
（5）分别利用左上角1、3、6个系数重建图像，计算相应的SAD，并由此分析直流和低频系数的重要性。
-Known brightness of two different image data block is as follows: (1) Principles of analysis of DCT, the DCT method, program and calculate the corresponding DCT coefficient, analysis of distribution coefficients. (2) quantitative analysis based on visual characteristics of the distribution of long-form features step-by-step to complete the DCT coefficient quantization. (3) the use of Z-scan output data to achieve statistical encoding, the formation of Video stream. (4) the use of the reconstructed image brightness IDCT data to calculate the SAD size, analysis of the causes of errors and the use of DCT for the principle of data compression. () (5), respectively, a factor of 1,3,6 using the upper left corner of the reconstruction of images, calculating the corresponding SAD, and the resulting analysis of DC and the importance of low-frequency coefficients. Platform: |
Size: 1024 |
Author:张元 |
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Description: Very thorough discussion of Data Hiding / Steganography / Watermarking of video with DCT-Very thorough discussion of Data Hiding/Steganography/Watermarking of video with DCT Platform: |
Size: 4235264 |
Author:SimonS65 |
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Description: Abstract- H.264/AVC is becoming a popular video codec for
its better compression ratio, lower distortion and applicability
to portable electronic devices. Thus, issues of copyright
protection appropriate for this standard become very
important. In this paper, a new blind SVD (Singular Value
Decomposition) - DCT combined video watermarking scheme
for the ".264 standard is proposed. The proposed method is a
blind watermarking algorithm as the hidden information can be
extracted without the original video and the original singular
values. To reduce visual quality degradation caused by
coefficients modifying, the perceptual model and block selection
mechanism are introduced to control the modification strength.
The performance of the proposed algorithm is evaluated with
respect to imperceptibility, robustness and data payload.
Experimental results reveal that the proposed scheme achieves
enough robustness while preserving the perceptual quality.-Abstract- H.264/AVC is becoming a popular video codec for
its better compression ratio, lower distortion and applicability
to portable electronic devices. Thus, issues of copyright
protection appropriate for this standard become very
important. In this paper, a new blind SVD (Singular Value
Decomposition)- DCT combined video watermarking scheme
for the ".264 standard is proposed. The proposed method is a
blind watermarking algorithm as the hidden information can be
extracted without the original video and the original singular
values. To reduce visual quality degradation caused by
coefficients modifying, the perceptual model and block selection
mechanism are introduced to control the modification strength.
The performance of the proposed algorithm is evaluated with
respect to imperceptibility, robustness and data payload.
Experimental results reveal that the proposed scheme achieves
enough robustness while preserving the perceptual quality. Platform: |
Size: 486400 |
Author:lie |
Hits:
Search - data in video dct