On Wed, 2012-06-13 at 15:08 -0500, Christofer C. Bell wrote: > The ImageMagick "identify" command could be used on the image to > gather statistics (such as pixel size) do some math on it, and feed > that back to mogrify, giving you some consistency in output. > > Example: > > cbell@circe:~$ identify testimage.jpg > testimage.jpg JPEG 4752x3168 4752x3168+0+0 8-bit DirectClass 5.706MB > 0.000u 0:00.000 > cbell@circe:~$ > > Grab field 3, do some math to determine aspect ratio, compare the > current resolution against your target, figure out the new size for > the image, feed that back to mogrify to resize it correctly. > > Want something smaller than 800x600? > > In the above, the image is 4752 x 3168. We want the image to be > smaller than 800x600. We need to decrease the image size by the > larger of 4752/800 or 3168/600. These are 5.28 and 5.94 respectively. > So we need to decrease the image to 16.8% of its current size > (1/5.94). > > cbell@circe:~$ mogrify -resize 16.8% testimage.jpg > cbell@circe:~$ identify testimage.jpg > testimage.jpg JPEG 798x532 798x532+0+0 8-bit DirectClass 239KB 0.000u 0:00.010 > cbell@circe:~$ > > Goal achieved.
It's much simpler to do: mogrify -resize '800x600<' testimage.jpg or to limit it to 800 in any dimension mogrify -resize '800x800<' testimage.jpg (These commands preserve aspect ratio and only resize if image is greater than the given dimensions.) -- Tixy -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/1339654726.3066.6.ca...@computer2.home