Page 1 of 1
How to use kernels larger than 10 in unsharpmask?
Posted: 2008-10-16T14:58:09-07:00
by thodberg
I have never been able to use a kernel size larger than 10
when I use the commandline tool -unsharp.
What is the reason for this limitation?
In photoshop it is possible to use a radius/kernel size
larger than 10 and through this it is possible to obtain
effect that is similar to what is optained through
a high pass filter. For this reason it would be interesting
to use -unsharp with a kernel larger that 10.
Re: How to use kernels larger than 10 in unsharpmask?
Posted: 2008-11-05T18:40:41-07:00
by anthony
What happens when you try and what is your command line?
Re: How to use kernels larger than 10 in unsharpmask?
Posted: 2008-11-05T19:09:12-07:00
by fmw42
thodberg wrote:I have never been able to use a kernel size larger than 10
when I use the commandline tool -unsharp.
What is the reason for this limitation?
In photoshop it is possible to use a radius/kernel size
larger than 10 and through this it is possible to obtain
effect that is similar to what is optained through
a high pass filter. For this reason it would be interesting
to use -unsharp with a kernel larger that 10.
It seems to work for me, but not much difference after 10.
convert rose: rose.jpg
convert rose: -unsharp 10 rose_us10.jpg
convert rose: -unsharp 100 rose_us10.jpg
I am running IM 6.4.5-3 Q16 Mac OSX Tiger
I think you need to play with the other parameters (sigma, amount, threshold)
If you use sigma rather than radius, ie. 0xsigma, then you get an effect similar to Photoshop
convert rose: -unsharp 0x10 rose_us0x10.jpg
convert rose: -unsharp 0x50 rose_us0x50.jpg
Re: How to use kernels larger than 10 in unsharpmask?
Posted: 2008-11-05T19:27:31-07:00
by magick
Amount and threshold are available in ImageMagick (e.g. -unsharp 0x1+amount+threshold).