Image Analysis Training: Difference of Gaussian

Difference of Gaussian (DoG)

Activity: Enhance spots in noisy image with uneven background

• Open image: xy_8bit__two_spots_noisy_uneven_background.tif
• Appreciate that you cannot readily threshold the spots
• Compute DoG: - Copy image and blur with a Gaussian of small sigma -> Gs - Copy image and blur with a Gaussian of bigger sigma -> Gb - For the official DoG: rb = sqrt(2) * rs - Create DoG = Gs - Gb
• Appreciate that now it is possible to threshold the spots in the DoG image

Learn more

• https://imagescience.org/meijering/software/featurej/
• https://en.wikipedia.org/wiki/Difference_of_Gaussians
• https://github.com/CellProfiler/CellProfiler/blob/master/cellprofiler/modules/enhanceorsuppressfeatures.py#L4