[magick-users] Mathematical Cloud Composition

[Ross Presser]

Thanks.  The clouds are actually starting to clear up ... in my head,
that is. :=)

On 7/11/07, Anthony Thyssen <anthony at griffith.edu.au> wrote:
> "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>
> -----------------------------------------------------------------------------
>      "I am NOT a merry man!"   -- Worf, Startrek NG "Strike Zone"
> -----------------------------------------------------------------------------
>      Anthony's Home is his Castle     http://www.cit.gu.edu.au/~anthony/
>