A Novel Contour Tracing Algorithm for Object Shape Reconstruction Using Parametric Curves

Parametric curves such as Bézier and B-splines, originally developedfor the design of automobile bodies, are now also used in image processing andcomputer vision. For example, reconstructing an object shape in an image,including different translations, scales, and orientations, can be performedusing these parametric curves. For this, Bézier and B-spline curves can be generatedusing a point set that belongs to the outer boundary of the object. Theresulting object shape can be used in computer vision fields, such as searchingand segmentation methods and training machine learning algorithms. Theprerequisite for reconstructing the shape with parametric curves is to obtainsequentially the points in the point set. In this study, a novel algorithm hasbeen developed that sequentially obtains the pixel locations constituting theouter boundary of the object. The proposed algorithm, unlike the methods inthe literature, is implemented using a filter containing weights and an outercircle surrounding the object. In a binary format image, the starting point ofthe tracing is determined using the outer circle, and the next tracing movementand the pixel to be labeled as the boundary point is found by the filter weights.Then, control points that define the curve shape are selected by reducing thenumber of sequential points. Thus, the Bézier and B-spline curve equationsdescribing the shape are obtained using these points. In addition, differenttranslations, scales, and rotations of the object shape are easily provided bychanging the positions of the control points. It has also been shown that themissing part of the object can be completed thanks to the parametric curves.

BACKGROUND RECONSTRUCTION AND OBJECT EXTRACTION BASED ON COLOR AND OBJECT TRACKING

In YCbCr colorspace, a method is proposed to reconstruct the background and extract moving objects based on the Gaussian model of chroma components. Background model is updated according to changes of chroma components. In order to eliminate the disturbance of shadow, a shadow detecting principle is proposed in YCbCr colorspace. A Kalman filter is introduced to estimate objects＇ positions in the image and then the pedestrian is tracked according to its information of shape. Experiments show that the background reconstruction and updating are successful, object extraction and shadow suppression are satisfactory, and real-time and reliable tracking is realized.

Single-molecular methodologies for the physical biology of protein machines

Physical biology is an interdisciplinary field that bridges biology with physical sciences and engineering.Singlemolecule physical biology focuses on dynamics of individual biomolecules and complexes,aiming to answering basic questions about their functions and mechanisms.It takes advantages of physical methodologies to gain quantitative understanding of biological processes,often engaging precise physical measurements of reconstructed objects to avoid interference from unnecessary complications.In this review,we(i)briefly introduce concepts of single-molecule physical biology,(ii)describe extensively used single-molecule methodologies that have been developed to address key questions in two important objects of single-molecule physical biology,namely,nucleic acid-interacting proteins and membraneinteracting proteins,and(iii)show by a few successful examples how one may use single-molecule methods to deepen our understanding of protein machines.

The reconstruction of diffractive object digital hologramat a short distance

By using a spherical wave as the reference wave, we recorded the in-line phase-shifting digital hologram of the 25th element of Chinese standard No. 3 resolution test pattern, and gave the corresponding numerical reconstructed results. Some problems concerning with the digital hologram recording and reconstruction of the diffractive object at a short distance are discussed. The experimental result shows that the resolution of the reconstructed image is better than 10μm, which is the limit by using this experimental arrangement.

Development of projection-type optical scheme for computer-generated Fourier hologram recorder

Projection-type recorders of computer-generated Fourier holograms have potential due to the decreased precision requirements of the optical scheme compared to most known holographic data recorders based on two-beam schemes.In the case of optical memory system development,the reduction factor of the projection scheme requires the application of properly developed optical components.The present report is dedicated to the development of special objectives for the projection scheme of computer-generated Fourier holograms.