15 research outputs found
Marca d'agua para documentos via modulação de luminância
Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Elétrica
ИНТЕЛЛЕКТУАЛЬНЫЙ числовым программным ДЛЯ MIMD-компьютер
For most scientific and engineering problems simulated on computers the solving of problems of the computational mathematics with approximately given initial data constitutes an intermediate or a final stage. Basic problems of the computational mathematics include the investigating and solving of linear algebraic systems, evaluating of eigenvalues and eigenvectors of matrices, the solving of systems of non-linear equations, numerical integration of initial- value problems for systems of ordinary differential equations.Для більшості наукових та інженерних задач моделювання на ЕОМ рішення задач обчислювальної математики з наближено заданими вихідними даними складає проміжний або остаточний етап. Основні проблеми обчислювальної математики відносяться дослідження і рішення лінійних алгебраїчних систем оцінки власних значень і власних векторів матриць, рішення систем нелінійних рівнянь, чисельного інтегрування початково задач для систем звичайних диференціальних рівнянь.Для большинства научных и инженерных задач моделирования на ЭВМ решение задач вычислительной математики с приближенно заданным исходным данным составляет промежуточный или окончательный этап. Основные проблемы вычислительной математики относятся исследования и решения линейных алгебраических систем оценки собственных значений и собственных векторов матриц, решение систем нелинейных уравнений, численного интегрирования начально задач для систем обыкновенных дифференциальных уравнений
Application and Theory of Multimedia Signal Processing Using Machine Learning or Advanced Methods
This Special Issue is a book composed by collecting documents published through peer review on the research of various advanced technologies related to applications and theories of signal processing for multimedia systems using ML or advanced methods. Multimedia signals include image, video, audio, character recognition and optimization of communication channels for networks. The specific contents included in this book are data hiding, encryption, object detection, image classification, and character recognition. Academics and colleagues who are interested in these topics will find it interesting to read
INFORMATION THEORETIC CRITERIA FOR IMAGE QUALITY ASSESSMENT BASED ON NATURAL SCENE STATISTICS
Measurement of visual quality is crucial
for various image and video processing applications. It is widely
applied in image acquisition, media transmission, video compression,
image/video restoration, etc.
The goal of image quality assessment (QA) is to develop a computable
quality metric which is able to properly evaluate image quality. The
primary criterion is better QA consistency with human judgment.
Computational complexity and resource limitations are also concerns
in a successful QA design. Many methods have been proposed up to
now. At the beginning, quality measurements were directly taken from
simple distance measurements, which refer to mathematically signal
fidelity, such as mean squared error or Minkowsky distance. Lately,
QA was extended to color space and the Fourier domain in which
images are better represented. Some existing methods also consider
the adaptive ability of human vision. Unfortunately, the Video
Quality Experts Group indicated that none of the more sophisticated
metrics showed any great advantage over other existing metrics.
This thesis proposes a general approach to the QA problem by
evaluating image information entropy. An information theoretic model
for the human visual system is proposed and an information theoretic
solution is presented to derive the proper settings. The quality
metric is validated by five subjective databases from different
research labs. The key points for a successful quality metric are
investigated. During the testing, our quality metric exhibits
excellent consistency with the human judgments and compatibility
with different databases. Other than full reference quality
assessment metric, blind quality assessment metrics are also
proposed. In order to predict quality without a reference image, two
concepts are introduced which quantitatively describe the
inter-scale dependency under a multi-resolution framework. Based on
the success of the full reference quality metric, several blind
quality metrics are proposed for five different types of distortions
in the subjective databases. Our blind metrics outperform all
existing blind metrics and also are able to deal with some
distortions which have not been investigated