Statistical analysis of speckle fields in digital laser monitoring of the microstructure of paper

It has been shown that digital dynamic speckle photography is an effective method for quantitative diagnostics of changes in the structure of paper processed by pulsed discharge. A theory of the dynamic statistics of speckle fields and mathematical relations are given. In using optical magnification \(\mathfrak{M}\) = 1, the software developed permits fast statistical processing of up to 250,000 microzones in a two-dimensional CCD image of size 20 × 30 mm. The results obtained point to a high spatial and temporal resolution of the method and the possibility of its real-time realization. It has been shown that noise filtering is an important part of speckle image processing. The software permits filtering both in direct calculation of the correlation function and in the Fourier plane with the use of the fast Fourier transform.