The purpose of this project was to investigate how to use image
processing techniques to obtain information about the formation of
the paper web throughout the wet-end of a paper machine. The goal
is to remove a periodic pattern caused by the wire in order to study
the fibre flocs.
Digital Image processing was studied and the topics of restoration,
enhancement and analysis were investigated in order to find the best
solution to the problem. It was found that the filtering of the images
is best performed in the Fourier domain because of the properties
of the images.
When experimenting, Matlab was used. Two filtering methods were examined.
One used a thresholding method to create a mask and the other was
two-dimensional Wiener filtering. The thresholding method is hard
to implement and produced a non-satisfying result with difficulties
in finding a sufficient model. Wiener filtering is an easy method
to implement and the results were satisfying. However, further experiments
could be performed in order to identify the noise factor properly.
