Temporal Contrast Analysis Using Correlation Between Frames

Speckle contrast analysis had been used for multiples purposes, for instance, laser speckle contrast imaging (LSCI) has been used to estimate the relative blood flow speed in a non-invasive way. The speckle contrast can be calculated using a spatial or temporal algorithm or a combination of both. Our work focuses into the contrast temporal algorithm. A contrast image calculated with the temporal contrast algorithm requires a sequence of L equal-sized frames. The contrast images are performed pixel by pixel, however, the experimental contrast calculation does not match with the current temporal theoretical model especially when the exposure time T is smaller than the correlation time tau(c). In this work, we propose to correlate neighboring pixels along the temporal axis to improve the contrast calculation. The contrast measurements using our proposal provide a better agreement than the current models.