Study on Defocused Image Processing Method for Particle Size Measurement

Particle size and size distribution are vital in the measurement of particle or particulate multiphase flow which is present in various industrial applications including fume monitoring and flow control in pipeline transportation. However, particle images investigating size and distribution are significantly influenced by defocus, and effective images processing methods are required to deal with these images. The defocused image processing method proposed by this chapter includes pre-processing, boundary detection of blurred particles, and criteria introduced to decide whether to count a particle given its degree of blur which aims to increase recognition accuracy and efficiency in size measurement of defocus blurred particles. Experiments are carried out to validate the proposed image processing method.