findimagedupes(1)
NAME
findimagedupes - Finds visually similar or duplicate images
SYNOPSIS
findimagedupes [option ...] [--] [ - | [file ...] ]
Options:
-f, --fingerprints=FILE -c, --collection=FILE
--merge=FILE -p, --program=PROGRAM
--prune -s, --script=FILE
-a, --add
-r, --rescan -q, --quiet
-n, --no-compare -v, --verbosity=LIST
-d, --debug=OPTS
-t, --threshold=AMOUNT
-h, --help
-0, --null --man
With no options, compares the specified files and does not use nor
update any fingerprint database.
Directories of images may be specified instead of individual files;
Sub-directories are NOT searched recursively.
INSTALLATION
If you use linux, your distribution may include a prepackaged version.
For example, Debian and Ubuntu do.
Otherwise, at a minimum you'll need Perl with the modules listed at the
top of the findimagedupes script. Also the GraphicksMagick package.
You may need to change Inline's "DIRECTORY" to point somewhere else.
Read the Inline module documentation for details.
OPTIONS
- -0, --null
- If a file "-" is given, a list of files is read from stdin.
- Without -0, the list is specified one file per line, such as produced by find(1) with its "-print" option.
- With -0, the list is expected to be null-delimited, such as produced by find(1) with its "-print0" option.
- -a, --add
- Only look for duplicates of files specified on the commandline.
- Matches are also sought in any fingerprint databases specified.
- -c, --collection=FILE
- NOT IMPLEMENTED (does anyone use this option?)
- Create GQView collection FILE.gqv of duplicates.
- -d, --debug=OPTS
- Enable debugging output. Options OPTS are subject to change. See the program source for details.
- -f, --fingerprints=FILE
- Use FILE as fingerprint database.
- May be abbreviated as --fp or --db.
- This option may be given multiple times when --merge is used. (Note: FILE could contain commas, so multiple databases may not be specified as a single comma-delimited list.)
- -h, --help
- Print usage and option sections of this manual.
- --man Display the full documentation, using default pager.
- --merge=FILE
- Takes any databases specified with --fingerprints and merges them into a new database called FILE. Conflicting fingerprints for an image will cause one of two actions to occur:
- 1. If the image does not exist, then the entry is elided.
- 2. If the image does exist, then the old information is
ignored and a new fingerprint is generated from scratch. - By default, image existence is not checked unless there is a
conflict. To force removal of defunct data, use --prune as well. - A list of image files is not required if this option is used.
However, if a list is provided, fingerprint data for the files will be copied or (re)generated as appropriate. - When --merge is used, the original fingerprint databases are not modified, even if --prune is used.
- See also: --rescan
- -n, --no-compare
Don't look for duplicates. - -p, --program=PROGRAM
Launch PROGRAM (in foreground) to view each set of dupes. - See also: --script.
- --prune Remove fingerprint data for images that do not exist any more. Has no effect unless --fingerprints or --merge is also used.
- Databases specified by --fingerprints are only modified if --merge is not used.
- -q, --quiet
This option may be given multiple times. - Usually, progress, warning and error messages are printed on
stderr. If this option is given, warnings are not displayed.
If it is given twice or more, errors are not displayed either. - Information requested with --verbosity is still displayed.
- -r, --rescan
(Re)generate all fingerprints, not just any that are unknown. - If used with --add, only the fingerprints of files specified on the commandline are (re)generated.
- Implies --prune.
- -s, --script=FILE
When used with --program, PROGRAM is not launched immediately. Instead sh(1)-style commands are saved to FILE. This script may be edited (if desired) and then executed manually. - When used without --program, a skeletal shell function "VIEW" is generated, which simply echo(1)s its arguments.
- To display to terminal (or feed into a pipe), use "-" as FILE.
- -t, --threshold=AMOUNT
Use AMOUNT as threshold of similarity. Append "%" to give a percentage or "b" for bits. For backwards compatibility, a
number with no unit is treated as a percentage. Percentage is
the minimum required for a match; bits is the maximum that may differ: bits=floor(2.56(100-percent)) - A fractional part may be given but it is only accurate to
100/256 (0.390625) for percentage and it is meaningless for
"bits". Default is "90%" ("25b") if not specified. - -v, --verbosity=LIST
Enable display of informational messages to stdout, where LIST is a comma-delimited list of: - md5 Display the checksum for each file, as per md5sum(1).
- fingerprint | fp
Display the base64-encoded fingerprint of each file. - Alternatively, --verbosity may be given multiple times, and accumulates. Note that this may not be sensible. For example, to be useful, md5 output probably should not be merged with fingerprint data.
DESCRIPTION
findimagedupes compares a list of files for visual similarity.
- To calculate an image fingerprint:
- 1) Read image.
2) Resample to 160x160 to standardize size.
3) Grayscale by reducing saturation.
4) Blur a lot to get rid of noise.
5) Normalize to spread out intensity as much as possible.
6) Equalize to make image as contrasty as possible.
7) Resample again down to 16x16.
8) Reduce to 1bpp.
9) The fingerprint is this raw image data. - To compare two images for similarity:
1) Take fingerprint pairs and xor them.
2) Compute the percentage of 1 bits in the result.
3) If percentage exceeds threshold, declare files to be similar.
RETURN VALUE
0 Success.
- 1 Usage information was requested (--help or --man), or there were
- warnings.
- 2 Invalid options or arguments were provided.
- 3 Runtime error.
- Any other return values indicate an internal error of some sort.
DIAGNOSTICS
To be written.
EXAMPLES
To be written.
FILES
To be written.
BUGS
There is a memory leak somewhere.
Killing the programme may corrupt the fingerprint database(s).
Changing version of GraphicsMagick invalidates fingerprint databases.
NOTES
Directory recursion is deliberately not implemented: Composing a filelist and using it with "-" is a more flexible approach.
Repetitions are culled before comparisons take place, so a commandline
like "findimagedupes a.jpg a.jpg" will not produce a match.
The program needs a lot of memory. Probably not an issue, unless your
machine has less than 128MB of free RAM and you try to compare more
than a hundred-thousand files at once (and the program will run quite
slowly with that many files anyway---about eight hours initially to
generate fingerprints and another ten minutes to do the actual
comparing).
SEE ALSO
gqview - A simple image viewer using GTK+
AUTHOR
Jonathan H N Chin <code@jhnc.org>
COPYRIGHT AND LICENSE
Copyright 2006 by Jonathan H N Chin <code@jhnc.org>.
This program is free software; you may redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
HISTORY
- This code has been written from scratch. However it owes its existence
to findimagedupes by Rob Kudla and uses the same duplicate-detection
algorithm.