The dark-adapted cone electroretinogram (ERG) is difficult to isolate because of unwanted rod intrusion. We compare dark-adapted cone estimates derived using three techniques. The first uses the cone response on a moderate rod saturating background to estimate the dark-adapted cone response. The second uses red and blue flashes to tease apart cone and rod responses (red-minus-blue technique, [I...

The selection of features extracted for image retrieval is quite important. We in this paper choose standard deviation and kurtosis to character texture. Non-subsampled shearlet transform is used to derive texture features. Shearlet is a new sparse representation tool of multidimensional function, which provides a simple and efficient mathematical framework. We firstly decompose the source imag...

In this paper, we study the construction of irregular shearlet systems, i.e., systems of the form SH(ψ,Λ) = {a− 4 ψ(A−1 a S−1 s (x− t)) : (a, s, t) ∈ Λ}, where ψ ∈ L(R), Λ is an arbitrary sequence in R ×R×R2, Aa is a parabolic scaling matrix and Ss a shear matrix. These systems are obtained by appropriately sampling the Continuous Shearlet Transform. We derive sufficient conditions for such a d...

PURPOSE To determine the extent of rod and cone photoreceptor dysfunction in patients with cone dystrophy using psychophysical and electrophysiological tests. METHODS Ten patients with cone dystrophy participated. Rod and cone system psychophysical thresholds were measured as a function of retinal eccentricity. Bright-flash full-field electroretinograms were obtained under dark-adapted (rod-m...

Two cone mechanisms are identifiable in the strongly yellow light-adapted electroretinogram (ERG) of the arterially perfused cat eye. One has its maximum spectral sensitivity near 555 nm; the other has its maximum near 450 nm. The former cone system produces a much larger signal with characteristics of a typical cone or inhibitory ERG. The latter cone system produces a small, saturable signal (...

In this paper we provide a construction of multiscale systems on a bounded domain Ω ⊂ R coined boundary shearlet systems, which satisfy several properties advantageous for applications to imaging science and numerical analysis of partial differential equations. More precisely, we construct a boundary shearlet system that forms a frame for L(Ω) with controllable frame bounds and admits optimally...

Shearlet as a new multidirectional and multiscale transform is optimally efficient in representing images containing edges. In this paper, a total variation based multivariate shearlet adaptive shrinkage is proposed for discontinuity-preserving image denoising. The multivariate adaptive threshold is employed to reduce the noise. Projected total variation diffusion is used to suppress the pseudo...

Despite the growing growth of technology, handwritten signature has been selected as the first option between biometrics by users. In this paper, a new methodology for offline handwritten signature verification and recognition based on the Shearlet transform and transfer learning is proposed. Since, a large percentage of handwritten signatures are composed of curves and the performance of a sig...

The inversion of the Radon transform is a classical ill-posed inverse problem where some method of regularization must be applied in order to accurately recover the objects of interest from the observable data. A well-known consequence of the traditional regularization methods is that some important features to be recovered are lost, as evident in imaging applications where the regularized reco...

in this paper, we focus on the study of shearlet transform which isde ned by using the hyperbolic functions. as a result we check an admissibilitycondition such that implies the reconstruction formula. to this end, we will usethe concept of the classical shearlet, which indicates the position and directionof a singularity.