Range of radius, sigma, amount, threshold...

[lelldorin]

Hello all,

during testing imagemagick on Haiku (OS), i create a little GUI to store my learned knowledge. Here i use at the moment text fields for enter the numers for "radius", "sigma", "amond", "threshold"... I wanrt to use here sliders to set this numers, but i does not know the range for this widgets.

Iirc i read anythere that radius have -99.9 to +99.9.

Can you help me? I does not found any information in den docs about it.

Greetings Lelldorin

[fmw42]

You have not said what the operator is, but I suspect it is -unsharp. See http://www.imagemagick.org/script/comma ... hp#unsharp. I believe these are the limitations you want.

radius >= 0 (a negative radius make no sense)
sigma >= 0 (a negative sigma is like standard deviation makes no sense)
amount >= 0 (amount is like a gain, you may be able to use negative values, but you would get a weird result)
theshold between 0 and 1 (values are expressed as a fraction of the quantum range)

In Photoshop, they use sliders that may be limited to certain ranges, simply for convenience . But in ImageMagick, there are no sliders and one can usually put in an values.

[lelldorin]

Thanks fmw42,

it is correct that i does not said that operator, because i want to know it of all operators . Is there any right lines for the operator settings like (factor, brightness...)?

[fmw42]

Thanks fmw42,

it is correct that i does not said that operator, because i want to know it of all operators . Is there any right lines for the operator settings like (factor, brightness...)?

The -unsharp operator has no arguments called factor or brightness. Sorry, I do not understand your question. Each ImageMagick operator can accept any value, but only certain ones make sense. There are no standard values for all operator arguments.

[lelldorin]

Thanks for your reply