How to make applescript to select every 3rd file to move to new folder?

Question

I have an interesting 'problem' I think.
As a result of a time-lapse experminent, I have a folder which holds several thousands of pictures from a fixed point, made over several days & nights.
But there is one issue: the camera made 3 different exposures every 5 seconds.
This resulted in every 3rd picture 'belonging' to each other. So these have to be selected for going in a seperate folder. Menaing: pictures 1 and 4 and 7 and 10 .... they must go in one folder. 2 and 4 and 8 and 11.. in the second folder. Finally 3 and 5 and 9 and 12 in a third folder.
How to do this with software (to avoid injury) because of the thousands of pics.
Is this do-able with applescript? How?
Tnx

Answer 1

Hello
You may try something like the following script.
Main part is written in shell script for performance sake. AppleScript is only used for user interface.
Please see comments in script for its usage and behaviour.
And please test the script first with small subset of your images.
(Since the script will scan the source folder tree for image files, it is good idea not to create destination folders in source folder tree.)
Minimally tested with OSX10.2 at hand but NO WARRANTIES of any kind.
Make sure you have full backup of your images before applying this script.
Hope this may help,
H
image file (jpg) sorter
v0.2
Script will let you choose two folders, i.e. -
a) source folder where images reside (directory tree under the chosen folder is scanned),
b) destination parent folder where three subfolders will be made (named '0', '1', '2').
The file number i is obtained by removing extension and non-digts from file name.
The file with number i (0-based) in source tree will be moved to (i mod 3)'th subfolder in destination.
e.g.,
IMG_1440.JPG -> '0' (i = 1440, i mod 3 = 0)
IMG_1441.JPG -> '1' (i = 1441, i mod 3 = 1)
IMG_1442.JPG -> '2' (i = 1442, i mod 3 = 2)
IMG_1443.JPG -> '0' ...
IMG_9997.JPG -> '1'
IMG_9998.JPG -> '2'
IMG_9999.JPG -> '0'
IMG_0001.JPG -> '1'
IMG_0002.JPG -> '2'
IMG_0003.JPG -> '0'
image file name convention : ZZZZ_9999.jpg
set src to choose folder with prompt "Choose source folder."
set src_ to (src's POSIX path's text 1 thru -2)'s quoted form
set dst to choose folder with prompt "Choose destination parent folder."
set dst_ to (dst's POSIX path's text 1 thru -2)'s quoted form
set sh to "
# source directory
srcdir=" & src_ & ";
# destination directories
dstdir=" & dst_ & ";
dest=("$dstdir"/{0,1,2});
# make destinations
mkdir -p "${dest[@]}";
# let k = number of destination directories
k=${#dest[@]};
# sort files to destinations such that -
# 1) number i is obtained by removing extension and non-digits from file name; and
# 2) file with number i is stored in (i % k)'th destination, where i is zero-based.
# e.g. Given xxxx_9999.jpg, k = 3;
# i = 9999 and the file is sorted to destination 0 (= 9999 mod 3)
find "$srcdir" -type f -iname '*.jpg' -print0 | while read -d $'\0' f;
do
leaf=${f##*/}; # get file name
stem=${leaf%.*}; # remove extension
i=${stem//[^0-9]/}; # remove non-digts from file name
let i=0+10#$i; # to interpret, e.g., 010 as 10, otherwise 010 is treated as octal.
# echo "$i $f ${dest[i % k]}"; # for testing
mv "$f" "${dest[i % k]}"; # move file
done
do shell script sh
display dialog "Done" with icon 1 giving up after 20