[magick-users] Color to B&W

[Anthony Thyssen]

Hugemann on  wrote...
| For test purposes you may establish any other color weighting by use of 
| the -fx operator, for instance:
| 
| convert -fx '0.3*r+0.4*g+0.3*b' rgb.gif gray.jpg
| 
First.   Read the image before you process it  ;-)
get into the habit of doing this and you will not get into the
trouble that existed with IM v5.

For speed and larger images I suggest you linit that to just one
channel, and then separate that channel as a greyscale image.  :-)

  convert rgb.gif -channel R -fx '0.3*r+0.4*g+0.3*b' -separate grey.gif

With a very large image the above will be at least twice as fast.


  Anthony Thyssen ( System Programmer )    <A.Thyssen at griffith.edu.au>
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