Rapidly changing phenomena, such as shock waves in laser-induced cavitation, are more difficult to observe, so we need special advanced illumination systems that are capable of generating short laser pulses lasting a few nanoseconds. These often result in a speckled pattern in the image, which is a consequence of the interference of the light with which we illuminate. As part of the task, we performed a digital analysis of the images and determined the speckle contrast, which is a consequence of the degree of coherence of the illumination. We found that the calculation of the contrast is affected by the background and also performed shock wave detection using bilateral filtering.
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