Math Calculations on string constants

[fmw42]

Fx includes the constant QuantumRange. Use it to scale Fx values to the quantum-depth of the ImageMagick release.

Yes, I had never noticed that before. This will be very useful to replace several lines of code in many of my scripts.

However, I am still puzzled how to do any calculation using fx escapes acting upon a string constant such as %{mean] for example.

What I came up with is three awkward alternates and am hoping there is a simpler way.

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mean=`convert image -format "%[mean]" info:`
convert xc: -format "%[fx:255*$mean/quantumrange]" info:

which I can then merge into one awkward command line either as

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echo "scale=0; $(convert image -format "%[mean]" info:) * 255/quantumrange" | bc

or

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convert xc: -format "%[fx:int($(convert image -format "%[mean]" info:)*255/quantumrange)]" info:

This calculation is not anything particular but just an example. I am looking for some way perhaps of doing it more compactly, such as (which does not work):

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convert image -format "%[fx:%[mean]*255/quantumrange}" info:

Is anything like this possible?

Thanks for any suggestions or improvements

Fred

[magick]

Grab ImageMagick 6.4.0-11 from ftp://magick.imagemagick.org/pub/ImageMagick/beta in about an hour. Fx now includes 'mean' and 'std':

• convert logo: -format '%[fx:QuantumRange*mean]' info:
  59085.2

[fmw42]

Thanks. That is terrific.

Don't mean to be a bother, but if it is not too much to ask, could you include the min and max as well. (or next release if you already have -11 finalized)

Fred

[magick]

We added

image.depth = image depth
image.minima = image minima
image.maxima = image maxima
image.mean = image mean
image.standard_deviation = image standard deviation

The patch will be available in just a few hours.