# A few questions on Difference of Gaussians [closed]

I use this formula for Difference of Gaussians (DoG): $\frac{1}{\sigma}(\frac{x^2}{2\sigma^2}-1.0)e^{\frac{-x^2}{2\sigma^2}}$

What is the relationship between this formula and the difference of two Gaussian functions?

Can someone show me how to apply DoG on a 1D signal in Matlab? My input can be considered as a 1D real-valued function, and I applied the above formula to detect blobs. The results make sense except that I don't know why I get so many local minimum in a relatively flat region (i.e., function values at points in the region almost stay constant). Since I don't have enough signal processing/image processing background, I want to see what a constant signal looks like after being convolved with a DoG filter.

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– Raphael Nov 24 '12 at 15:28
Crossposted on Signal Processing SE, which is probably a better place for it. – Peter Shor Nov 25 '12 at 0:16

## closed as off topic by Ran G., Pål GD, Raphael♦Jan 28 at 10:04

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