Legacy ImageMagick Discussions Archive

I was curious, so I checked the source of gimps sobel-.c They divide the end result by 5,66, which probably means 5,66 = sqrt(32) = sqrt(4^2 + 4^2) so essentially dividing each side by 4. I guess the maximum value the sobel mask can produce is 4*white: -1 0 1 B B W -2 0 2 over B B W -1 0 1 B B W = 1...

Thanks, this works: convert zelda3.JPG ^ ( -clone 0 -bias 50% -convolve "-1,0,1,-2,0,2,-1,0,1" ( +clone -negate ) -compose difference -composite ) ^ ( -clone 0 -bias 50% -convolve "-1,-2,-1,0,0,0,1,2,1" ( +clone -negate ) -compose difference -composite ) ^ -delete 0 ^ -compose pl...

Thanks! I am using ImageMagick 6.5.4-2 2009-06-30 Q16 OpenMP on windows xp, so that is indeed the problem It seems like getting the HDRI version requires recompiling which I' drather avoid, but I can try if the other option does not work I tried your bias suggestion, however my results are not quite...

Hi I am trying to implement an edge detection by analysing fred's excellent gradient script, but something seems to be missing: Here is something that should work like a horizontal sobel: convert -size 50x50 xc:black -fill white -draw "circle 25,25 20,10" \ -convolve "-1,0,1,-2,0,2,-1...

Thanks!
Is there a "proper" way to do this, i.e. without reading the same file twice?

I am having some trouble with the -compose syntax, and need a hint. Here is a modified example of what I want to do: overlay an image with a vertically compresssed altered copy and a horizontal compressed altered copy of itself http://www.imagemagick.org/Usage/color/rose.png --> http://img146.images...

yeah, I added some.

Just wanted to share the following solution for a problem I was struggling with: problem: trimming a noisy images as per http://www.imagemagick.org/Usage/crop/#trim_blur specifically, digital camera shots of printed documents in front of a noisy background, one document per image. (I used my camera ...

when using -colorspace HSL and HSB, possibly YUV too together with some other options, like -fuzz, -opaque, or -trim weird things happen convert colorwheel.png -colorspace HSB -fill white -opaque blue opaque_blue.png http://img405.imageshack.us/img405/4458/opaqueblue.png convert colorwheel.png -colo...

I have been looking trough the source of the selective-blur algorithm to understand the results, and it is somewhat confusing: As far as i can make out, the algorithm does not perform a gaussian blur, but a square box-blur, i.e. the image is convolved with a 1,...,1 kernel, limited by the contrast t...

The new selective blur works nicely! Thanks a lot! I'd like to test if a gaussian distribution for choosing 'close' colors could give a bit better results than a hard contrast threshold, and am currently struggling with the code. (something like -selective-blur 0x10+0x20%, where the influence of eac...

We have a new -selective-blur option coded up and we're testing now. It will take a few days before its ready to test. very cool, did you implement that just now, or was that a coincidence? There is one improvement I thought of in comparison to the gimp algorithm: Maybe instead of a fixed threshold...

What you seem to want is to get a mix of the image. Where a pixel is close to the average of its neighbors by some threshold, you want to do a gaussian blur (-blur) and where it is not close, you want to leave the image alone. I am not absolutely sure what I want either :) What you describe is some...

You might want to try my gaussianedge script and see if that helps. see http://www.fmwconcepts.com/imagemagick/index.php I am using windows, but I may be able to figure out the equivalent windows commands from the script. However, as far as I can make out, the script blurs or sharpens near edges, w...

I am trying to replicate the effects of the Gimp filter "selective gaussian blur". I find it very useful in removing noise from scans. Reference: http://docs.gimp.org/en/plug-in-sel-gauss.html http://www.gimp.org/tutorials/Selective_Gaussian_Blur/ I tried the "adaptive-blur" swit...