Figure 7: Images from Figs 3, 4 and 5 at 2 ns delay passed through a Sobel filter to compute the gradient.
From: Enabling time resolved microscopy with random Raman lasing
The magnitude of the gradient is shown. This kind of filter is commonly used in image processing for edge detection as it highlights areas where contrast is high. Thus, in this case it is being used to highlight the higher degree of detail captured by random Raman lasing due to the lack of speckle while maintaining sufficient temporal resolution to capture the laser induced breakdown event.
