Learn More
Optical flow cannot be computed locally, since only one independent measurement is available from the image sequence at a point, while the flow velocity has two components. A second constraint is needed. A method for finding the optical flow pattern is presented which assumes that the apparent velocity of the brightness pattern varies smoothly almost(More)
The field of machine vision, or computer vision, has been growing at a fast pace. As in most fast-developing fields, not all aspects of machine vision that are of interest to active researchers are useful to the designers and users of a vision system for a specific application. This text is intended to provide a balanced introduction to machine vision.(More)
Image flow is the velocity field in the image plane caused by the motion of the observer, objects in the scene, or apparent motion. The image flow velocity field is an important intrinsic image and many algorithms that use the image flow velocity field have already been described. The image flow velocity field can contain discontinuities due to object(More)
A polymerase chain reaction (PCR) assay is described for the detection of parvovirus in feces of dogs and cats. A touch-down protocol was used which enabled the specific amplification of virion DNA from feces after a fast and simple boiling pretreatment. The sensitivity of PCR was as high as ten infectious particles per reaction which corresponds to a titer(More)
The immunogenicity, reactogenicity, and safety of an inactivated hepatitis A vaccine were assessed in anti-HIV positive homosexual men. Fourteen anti-HIV positive (group 1) and 20 anti-HIV negative (group 2) men received vaccine (containing 720 ELISA units of hepatitis A antigen per dose) intramuscularly at 0, 1, and 6 months. Twelve unvaccinated anti-HIV(More)