Blurring with mathematica

*To*: mathgroup at smc.vnet.net*Subject*: [mg54814] Blurring with mathematica*From*: V.Marinakis at damtp.cam.ac.uk*Date*: Wed, 2 Mar 2005 22:29:04 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Dear all, I have some questions regarding the following email: 1) Shouldn't it be the factor (1/Sqrt[2 Pi sdev^2]) in the kernel? 2) What should I change in order to normalise the gaussian to an interval of 1; Best, Vangelis Marinakis. -------------------------------------------------------------------- Generate an image. image = Table[Random[], {128}, {128}]; Show[Graphics[Raster[image]], AspectRatio -> 1]; Generate a Gaussian blurring kernel. halfwindow = 5; sdev = 2; kernel = Table[Exp[-((i^2 + j^2)/(2*sdev^2))], {i, -halfwindow, halfwindow}, {j, -halfwindow, halfwindow}]; Show[Graphics[Raster[kernel]], AspectRatio -> 1]; Blur the image. image2 = ListCorrelate[kernel, image]; image2 /= Max[image2]; Show[Graphics[Raster[image2]], AspectRatio -> 1]; If you want to blur with circular wraparound then use ListCorrelate[kernel, image, {{halfwindow + 1, halfwindow + 1}, {halfwindow + 1, halfwindow + 1}}]; Steve Luttrell <V.Marinakis@[EMAIL PROTECTED] > wrote in message news:cvrqhi$p5c$1@[EMAIL PROTECTED] > Hello everyone. > > I have an image which is stored as an 128 times 128 > matrix and I want to add gaussian blurring. Does anyone > know how can this be done with mathematica? > > Best, Vangelis Marinakis. >