As a generalization of the 2D Fourier transform (2D FT) and 2D fractional Fourier transform, the 2D nonseparable linear canonical transform (2D NsLCT) is useful in optics and signal and image processing. To reduce the digital implementation complexity of the 2D NsLCT, some previous works decomposed the 2D NsLCT into several low-complexity operations, including 2D FT, 2D chirp multiplication (2D...

We describe a case of abrupt cardiac arrest in an 80 year old woman. Emergent transoesophageal echocardiography (TOE) helped clarify the diagnosis of pulmonary embolism, and guide management and ongoing resuscitation. This case highlights the utility of TOE in the peri-arrest setting and in the diagnosis of massive pulmonary embolism. TOE can also be useful in providing prognostic information a...

We present two approaches for automatically segmenting the spinal cord/canal from native CT images of the thorax region containing the spine. Different strategies are included to handle images where only part of the spinal column is visible. The algorithms require one seed point given on a slice located in the middle region of the spine, and the rest is automatic. The spatial extent of the spin...

This paper presents in detail the Compact Union of Disjoint Boxes (CUDB), a decomposition model for binary volumes that has been recently but briefly introduced. This model is an improved version of a previous model called Ordered Union of Disjoint Boxes (OUDB). We show here, several desirable features that this model has versus OUDB, such as less unitary basic elements (boxes) and thus, a bett...

In imaging applications, computation is often carried out in a derivative (gradient) domain. For example, we can attenuate small image differences by thresholding the gradient and then reintegrate. Unfortunately, the reintegration is an expensive task. Reintegration is often carried out in 2D (usually using 2D Fourier transform) or through multiple 1D paths as in Retinex. In this paper, we show...

A new class of fractional 2D linear discrete-time systems is introduced. The fractional difference definition is applied to each dimension of a 2D Roesser model. Solutions of these systems are derived using a 2D Z-transform. The classical Cayley-Hamilton theorem is extended to 2D fractional systems described by the Roesser model. Necessary and sufficient conditions for the positivity and stabil...

Abstract: This paper presents a design method of 2-dimensional (2-D) FIR filters by successive projection (SP) method using multiple extreme frequency points based on Fritz John’s theorem. The proposed method enables an update of coefficients using multiple extreme frequency points by Fritz John’s theorem. Moreover, we also present two methods as how to choose the extreme frequency point for th...

Two-dimensional (2D) adaptive filtering is a technique that can be applied to many image and signal processing applications. This paper extends the one-dimensional adaptive filter algorithms to 2D structure and the novel 2D adaptive filters are established. Based on this extension, the 2D variable step-size normalized least mean squares (2D-VSSNLMS), the 2D-VSS affine projection algorithms (2D-...

There are many problems in science and engineering whose solution is applied in the design of Multi-Dimensional (MD) digital filters. Digital filtering finds an important position in the field of digital signal and image processing. Recently there had been a great deal of interest in the design and stability analysis of Two-Dimensional (2-D) recursive digital filters. The design techniques for ...