On Thu, Jun 14, 2012 at 1:18 AM, Tixy <t...@yxit.co.uk> wrote: > 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.)
Well, color me impressed! I didn't know about that notation. That certainly would have saved me a lot of pain with some shell scripts I wrote awhile back for image management! I'll keep that in my bag of tricks and thank you for the tip! -- Chris -- 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/caoevnyujsmftaqze+suzcvhjnvk48hnvjlngofzg5bxu-xv...@mail.gmail.com
