[magick-users] Problem with -extent

[Anthony Thyssen]

Eli Barzilay on  wrote...
| Hi,
| 
| I'm trying to get thumbnails that have a uniform height, but doing
| something like this:
| 
|   convert x.jpg -thumbnail '120x80>' -gravity center -extent 'x80<' xx.jpg
| 
| spits out "convert: no pixels defined in cache `x.jpg'." and has no
| visible effect on the resulting image.  Is this a bug or something
| wrong that I'm doing?
| 
well -extent is not right..  If you want to cut up an image use -crop.

As for what you want use...

   convert x.jpg  -thumbnail 'x80'  xx.jpg

the image will be resize to 80 pixels high,  always.
If you want a limit on width... add one...

   convert x.jpg  -thumbnail '250x80' xx.jpg

Which will make images 80 pixel high, unless the result is wider than
250 pixel, in which case it makes that the limit.

This prevents problems with very long images, like WWW divider lines.

For more see IM Examples...
   http://www.imagemagick.org/Usage/thumbnails/#height

That is the first practical examples on that page as that is often what
is wanted for web page thumbnails.


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