Saturday, Debtember 21, 2002
Manipulating images
One of the reasons I haven't been updated as I should is due to the delay in processing the images from the other day and I really wanted to get them done and posted before I resumed regular posting here so as to give you a chance to see them before they slide off the main page and into archival oblivion.
I took over 100 images that night.
There are two problems with selecting which images to choose from: one—Spring's computer, which has enough memory to process large images (the raw images are 1984×1488 high quality images—they average about 700K each) but her monitor is less than optimal for viewing images (it's a bit dim and the color is way off). Two—my computer has a much better monitor but seriously lacks the memory to process large images; with only 32M of RAM just working with one of these images is taxing (loaded into memory each image takes up some 11M of memory, and my system usually has 5M of physical RAM free so loading these images for processing causes the system to hit swap space pretty hard). Ideally, I wanted to convert these images down to a managable size to view them quickly and pick the ones I wanted, but I did not want to sit there resizing 100 images by hand (either on my machine or on Spring's).
Little did I realize that I had software to do batch conversions already installed—ImageMagick. It's a series of programs you can run from a command line to batch up processing of images, so convering 100 images is as easy as:
for i in *.JPG do echo Converting $i convert --sample 496x372 $i /tmp/$i done
And then go off and do something else while my computer crunches away.
And crunches. And crunches. And swaps. And swaps. And I mean seriously swaps. The harddrive LED was searingly bright.
For two hours.
I told Rob this, and he let me use his computer to do the processing. Since he also runs Linux, I was able to log into his computer from mine, use ImageMagick (since he had it installed) to do the mass conversion (less than five minutes for 100 images—sigh) and run the GIMP to do final tweaks on the images I did select.