Three-dimensional active vision system with high lateral resolution and large depth of field

1993 ◽  
Author(s):  
Li Song ◽  
Jean-Paul Boillot ◽  
Guylain Lemelin ◽  
Roger A. Lessard
Author(s):  
Daniel L. Barton ◽  
Jeremy A. Walraven ◽  
Edward R. Dowski ◽  
Rainer Danz ◽  
Andreas Faulstich ◽  
...  

Abstract A new imaging technique called Wavefront Coding allows real-time imaging of three-dimensional structures over a very large depth. Wavefront Coding systems combine aspheric optics and signal processing to achieve depth of fields ten or more times greater than that possible with traditional imaging systems. Understanding the relationships between traditional and modern imaging system design through Wavefront Coding is very challenging. In high performance imaging systems nearly all aspects of the system that could reduce image quality are carefully controlled. Modifying the optics and using signal processing can increase the amount of image information that can be recorded by microscopes. For a number of applications this increase in information can allow a single image to be used where a number of images taken at different object planes had been used before. Having very large depth of field and real-time imaging capability means that very deep structures such as surface micromachined MEMS can be clearly imaged with one image, greatly simplifying defect and failure analysis.


2015 ◽  
Vol 354 ◽  
pp. 321-329 ◽  
Author(s):  
Peng Wang ◽  
Songlin Xie ◽  
Xinzhu Sang ◽  
Duo Chen ◽  
Chenyu Li ◽  
...  

1993 ◽  
Vol 15 (1) ◽  
pp. 36-47 ◽  
Author(s):  
Tai K. Song ◽  
J-y. Lu ◽  
J. F. Greenleaf

A method to obtain a good compromise between the depth of field and the lateral resolution of “X waves” is proposed. The original X waves are theoretically nondiffracting beams generated by a specially phased infinite transmit aperture. When generated by a finite aperture, X waves are diffracting beams but have a large depth of field, maintaining uniform lateral field profiles. The proposed modification of the wave equation solution for X waves replaces a constant parameter representing the propagation angle of ultrasound with a function of radial distance at the aperture surface, and results in modified X waves that have a larger depth of field than the original X waves. Computer simulations show that a proper choice of the modification function can produce a new beam with improved field properties compared with the original X waves, promising images with higher lateral resolution and increased contrast over a large depth of field in high frame rate medical imaging. Experimental results are presented to verify the simulation results of the proposed method.


2020 ◽  
Vol 28 (21) ◽  
pp. 31197
Author(s):  
Xiaowei Hu ◽  
Song Zhang ◽  
Yujin Zhang ◽  
Yongpan Liu ◽  
Guijin Wang

2020 ◽  
Vol 18 (7) ◽  
pp. 071701
Author(s):  
Aiwang Huang ◽  
Danni Chen ◽  
Heng Li ◽  
Dexiang Tang ◽  
Bin Yu ◽  
...  

2018 ◽  
Vol 30 (3) ◽  
pp. 453-466 ◽  
Author(s):  
Shaopeng Hu ◽  
◽  
Mingjun Jiang ◽  
Takeshi Takaki ◽  
Idaku Ishii

In this study, we developed a monocular stereo tracking system to be used as a marker-based, three-dimensional (3-D) motion capture system. This system aims to localize dozens of markers on multiple moving objects in real time by switching five hundred different views in 1 s. The ultrafast mirror-drive active vision used in our catadioptric stereo tracking system can accelerate a series of operations for multithread gaze control with video shooting, computation, and actuation within 2 ms. By switching between five hundred different views in 1 s, with real-time video processing for marker extraction, our system can function asJvirtual left and right pan-tilt tracking cameras, operating at 250/Jfps to simultaneously capture and processJpairs of 512 × 512 stereo images with different views via the catadioptric mirror system. We conducted several real-time 3-D motion experiments to capture multiple fast-moving objects with markers. The results demonstrated the effectiveness of our monocular 3-D motion tracking system.


2019 ◽  
pp. 105971231987447
Author(s):  
Olalekan Lanihun ◽  
Bernie Tiddeman ◽  
Patricia Shaw ◽  
Elio Tuci

Biological vision incorporates intelligent cooperation between the sensory and the motor systems, which is facilitated by the development of motor skills that help to shape visual information that is relevant to a specific vision task. In this article, we seek to explore an approach to active vision inspired by biological systems, which uses limited constraints for motor strategies through progressive adaptation via an evolutionary method. This type of approach gives freedom to artificial systems in the discovery of eye-movement strategies that may be useful to solve a given vision task but are not known to us. In the experiment sections of this article, we use this type of evolutionary active vision system for more complex natural images in both two-dimensional (2D) and three-dimensional (3D) environments. To further improve the results, we experiment with the use of pre-processing the visual input with both the uniform local binary patterns (ULBP) and the histogram of oriented gradients (HOG) for classification tasks in the 2D and 3D environments. The 3D experiments include application of the active vision system to object categorisation and indoor versus outdoor environment classification. Our experiments are conducted on the iCub humanoid robot simulator platform.


Author(s):  
A.M. Jones ◽  
A. Max Fiskin

If the tilt of a specimen can be varied either by the strategy of observing identical particles orientated randomly or by use of a eucentric goniometer stage, three dimensional reconstruction procedures are available (l). If the specimens, such as small protein aggregates, lack periodicity, direct space methods compete favorably in ease of implementation with reconstruction by the Fourier (transform) space approach (2). Regardless of method, reconstruction is possible because useful specimen thicknesses are always much less than the depth of field in an electron microscope. Thus electron images record the amount of stain in columns of the object normal to the recording plates. For single particles, practical considerations dictate that the specimen be tilted precisely about a single axis. In so doing a reconstructed image is achieved serially from two-dimensional sections which in turn are generated by a series of back-to-front lines of projection data.


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