Search results for "Pinhole camera"
showing 3 items of 3 documents
Photorefractive “camera obscura”
2011
Abstract We demonstrate a novel scheme for lensless image formation which combines the properties of an amplifying dynamic hologram and a pinhole camera. The scheme is realized on the base of a SPS:Sb1% photorefractive crystal working at 633 nm.
X-ray imaging of the heating zone of non-normal incidence pumped XRL plasma
2006
Soft x-ray emission, above 600 eV, from a grazing incidence pumped Ni-like Mo x-ray laser (GRIP-XRL) [1] plasma was investigated. Using a pinhole camera looking along the target surface, perpendicular to the direction of the XRL emission, spatially-resolved information was obtained with a resolution which was limited only by the pinhole size of 10 μm. The relative distance from the target surface to the plasma zone heated by th e picosecond pulse was investigated for different GRIP angles, energy ratios and delays between the plasma producing and the plasma heating pulses.
Detecting motion independent of the camera movement through a log-polar differential approach
1997
This paper is concerned with a differential motion detection technique in log-polar coordinates which allows object motion tracking independently of the camera ego-motion when camera focus is along the movement direction. The method does not use any explicit estimation of the motion field, which can be calculated afterwards at the moving points. The method, previously formulated in Cartesian coordinates, uses the log-polar coordinates, which allows the isolation of the object movement from the image displacement due to certain camera motions. Experimental results on a sequence of real images are included, in which a moving object is detected and optical flow is calculated in log-polar coord…