Recently, the novel approach to Hough Transform (HT) calculation, regarded to as the Hough-Green Transform (HGT),
was proposed. This approach is based on tracing object contours on bitonal imagery; therefore it is usually much more
computationally effective than the Standard HT (SHT) on objects with a large number of interior pixels, as the
acceleration is proportional to area by circumference ratio. Although the purely software sequential HGT implementation
is very effective compared to the SHT and the Radon transform based alternatives, the algorithm allows designing a
parallel and scalable real-time architecture.
The novel approach to angular projection calculation on discrete binary images, regarded to as the Hough-Green Transform (HGT), based on tracing object contours is introduced. This approach is usually much more computationally effective than the conventional Standard HT (SHT) on objects with a lot of interior pixels, as the acceleration factor is proportional to area by circumference ratio. The HGT is also more accurate than the SHT.
To date, generally, light scattering devices used for the determination of particle size distribution and concentration of particles have been divided as devices for the monitoring of clean rooms (low concentration range) and devices for the measurement of dense aerosols (high concentration range). We report the design and development of a light scattering airborne partic- cle counter that differs both from the well-known optical particle counters, which have forward scattering geometry and a lower limit of registration of 0.5 pm, and the particle counters having a lower limit of registration of 0.1 - 0.3 pm, which have the disadvantage of placing the sampling chamber in- side the laser resonator and passing the particles through the open cavity la- ser. The new design of the opto-mechanical system and electronic makes it possible to use our device in the concentration range 10 - 5 106 partic- les/liter with high resolution of particle size. The use of aerodynamical fo- cusing of the tested air stream and an arrangement that places the measuring chamber outside the laser resonator combined with permanent stabilization of the photomultiplier provides an increase in the reliability of the device. The size detection limit of the system remains low enough (0.2pm).