[magick-users] Equivalence of convert command for Magick++

[Anthony Thyssen]

Elie Zedeck RANDRIAMIANDRIRAY on  wrote...
| Hello guys,
|
| I'm trying to transcribe this convert command (from the Usage example):
|
| convert mask_light.png -negate -background white -channel A -combine
| +channel mask_lighting.png
|
| into the equivalent for Magick++.
|
These is a more modern version of the example sequence the above was
taken from.  See  Advanced,  Better 3-D Logo Generation
   http://www.imagemagick.org/Usage/advanced/#3d-logos-2

It is also a VERY VERY old method. With the latest IM you can instead
use...

   convert mask_light.png  -background white -alpha shape   mask_lighting.png

Note that you do not need a 'negate' for the above, as the image is an
alpha channel greyscale mask, where combine uses a matte greyscale mask.

See IM Examples, Basics, Controlling Image Transparency, Shape
(converting a greyscale mask to a shaped mask)
   http://www.imagemagick.org/Usage/basics/#alpha_shape


However the implementation is also equivelent to

   convert mask_light.png  mask_light.png \
           +matte -compose CopyOpacity -composite \
           -fill white  -colorise 100%   mask_lighting.png

or using more modern options...

  convert mask_light.png  mask_light.png \
          -alpha off -compose CopyOpacity -composite \
          +level-colors white    mask_lighting.png

Those last few examples should be easy to convert to Magick++


ALL the above achieve the same result. This is convert a grayscale alpha
mask into a colored shape mask.


  Anthony Thyssen ( System Programmer )    <A.Thyssen at griffith.edu.au>
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   Symbolic Link(n) : ``A door closes quietly behind you, you are in a
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     Anthony's Home is his Castle     http://www.cit.gu.edu.au/~anthony/