نتایج جستجو برای: dual shearlet frame
تعداد نتایج: 255405 فیلتر نتایج به سال:
The analysis and detection of edges is a central problem in applied mathematics and image processing. A number of results in recent years have shown that directional multiscale methods such as continuous curvelet and shearlet transforms offer a powerful theoretical framework to capture the geometry of edge singularities, going far beyond the capabilities of the conventional wavelet transform. T...
Let {xn} be a frame for a Hilbert space H. We investigate the conditions under which there exists a dual frame for {xn} which is also a Parseval (or tight) frame. We show that the existence of a Parseval dual is equivalent to the problem whether {xn} can be dilated to an orthonormal basis (under an oblique projection). A necessary and sufficient condition for the existence of Parseval duals is ...
We regard the shearlet group as a semidirect product group and show that its standard representation is,typically, a quasiregu- lar representation. As a result we can characterize irreducible as well as square-integrable subrepresentations of the shearlet group.
Regularization te hniques for the numeri al solution of nonlinear inverse s attering problems in two spa e dimensions are dis ussed. Assuming that the boundary of a s atterer is its most prominent feature, we exploit as model the lass of artoon-like fun tions. Sin e fun tions in this lass are asymptoti ally optimally sparsely approximated by shearlet frames, we onsider shearlets as a means for ...
where A and B are called the lower frame bound and upper frame bound, respectively. In particular, when A= B = 1, we say that {hk}k∈Z is a (normalized) tight frame in H. The 1 Research was partially supported by NSF Grants DMS-9872890, DMS-9706753 and AFOSR Grant F4962098-1-0044. Web: http://www.princeton.edu/~icd. 2 Research was supported by NSERC Canada under Grant G121210654 and by Alberta I...
With the continuous development of synthetic aperture radar (SAR) technology, SAR image data are becoming increasingly abundant. For same scene, dual-frequency (high-frequency and low-frequency) images can present different details feature information. fusion two frequencies combine advantages both, thus describing targets more comprehensively. Because high-resolution contain a large amount det...
The fast digital shearlet transform (FDST) was recently introduced as a means to analyze natural images efficiently, owing to the fact that those are typically governed by cartoon-like structures. In this paper, we introduce and discuss a first-order hybrid sigma-delta quantization algorithm for coarsely quantizing the shearlet coefficients generated by the FDST. Radial oversampling in the freq...
Volumetric data acquisition and increasingly massive data storage have increased the need to develop better analysis tools for three-dimensional data sets. These volumetric data sets can provide information beyond that contained in standard two-dimensional images. Common strategies to deal with such data sets have been based on sequential use of two-dimensional analysis tools. In this work, we ...
Frame is the corner stone for designing decomposition and reconstruction operations in signal processing. Famous frames include wavelets, curvelets, and Gabor. A celebrated result indicates that if a synthesis frame is chosen for reconstruction, then its canonical dual frame is the analysis frame that performs decomposition, yielding coefficients that minimizes l2-norm of all coefficients of al...
We present a general method for construction of frames {ψI}I∈D for Triebel-Lizorkin and Besov spaces, whose nature can be prescribed. In particular, our method allows for constructing frames consisting of rational functions or more general functions which are linear combinations of a fixed (small) number of shifts and dilates of a single smooth and rapidly decaying function θ such as the Gaussi...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید