[magick-users] Mathematical Cloud Composition

[Anthony Thyssen]

"Ross Presser" on  wrote...
| Some information got lost somewhere in this email thread.  Your
| -compose just squares the clouds, it leaves out New Zealand
| completely.
| 
It was just an explaination.  My previous email had the FULL version...

Presumably that email was lost, so I'll resend it now.

---- Resend ----

  convert nzcloudstc9.jpg \( +clone \) -compose multiply -composite \
          \( +clone -fill white -colorize 100% \) +swap \
          -compose CopyOpacity -composite \
          nzdaylp9.png +swap +compose  -composite \
          cloud_overlayed.png

An alturnative to overlaying a 'masked' white is to use 'screen'
to brighten the image basied on the clouds (same result)
Note that 'screen' does not care about the order of the input images.

  convert nzcloudstc9.jpg \
          nzdaylp9.png -compose screen -composite   cloud_overlay.png

OR with squaring (to darken the overlay)

  convert nzcloudstc9.jpg \( +clone \) -compose multiply -composite \
          nzdaylp9.png -compose screen -composite    cloud_overlay.png

For more compose methods see..  IM examples
   http://www.imagemagick.org/Usage/compose/

Specifically look at multiply, copyopacity and screen

If you have the lastest IM, you can also try three image 'masked' overlays.


  Anthony Thyssen ( System Programmer )    <A.Thyssen at griffith.edu.au>
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     "I am NOT a merry man!"   -- Worf, Startrek NG "Strike Zone"
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     Anthony's Home is his Castle     http://www.cit.gu.edu.au/~anthony/