Re: Any quick, easy way to compare two images?

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From	john hevelin <bwotte@panix.com>
Newsgroups	comp.sys.mac.system
Subject	Re: Any quick, easy way to compare two images?
Date	Sat, 25 Jan 2014 18:51:21 +0000 (UTC)
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Beating a dead horse for my own satisfaction....

The original poster has a set of data which he submits to image
processing.  The OP might receive duplicate copies of the data set,
but does not want to process the duplicates.  The OP sought a way
to detect duplicate data.

Several utilities were suggested as solutions, including cmp(1),
diff(1), and something termed "XOR" which I'm not familiar with but
which I assume is some sort of CRC utility like sum(1) or md5(1).
Another poster suggested a motion detection application.

Several posters pointed out for image processing, many factors can
introduce changes in data that are not visually significant, and
hence a check for absolute equality would not have the result sought
by the OP.  The OP said this didn't matter, and is presumably
satisfied with the solutions at hand.

But suppose it did matter?  Suppose by theory or experiment we could
establish a threshold of difference between the data sets that would
enable us to process only the new sets with a meaningful probability
of the result being visually significant?

[Caveat:  I know nothing about image processing.]

The command cmp -l generates a list of the differing bytes in two
files.  For example, for these files:

% cat file1
How now brown cow.

% cat file2
Hoy not brown coi.
 
The command cmp -l produces:

% cmp -l file1 file2
 3 167 171
 7 167 164
17 167 151

If the count of differing bytes exceeds the pre-established threshold,
then process the data; otherwise, wait for the next batch of data.

Thread

Any quick, easy way to compare two images? Don Bruder <dakidd@sonic.net> - 2014-01-23 10:42 -0800
  Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-23 14:24 -0500
    Re: Any quick, easy way to compare two images? Don Bruder <dakidd@sonic.net> - 2014-01-23 13:00 -0800
      Re: Any quick, easy way to compare two images? Tom Stiller <clusterfux.upmon@gmail.com> - 2014-01-23 21:11 +0000
        Re: Any quick, easy way to compare two images? Don Bruder <dakidd@sonic.net> - 2014-01-23 16:38 -0800
          Re: Any quick, easy way to compare two images? john hevelin <bwotte@panix.com> - 2014-01-24 01:57 +0000
            Re: Any quick, easy way to compare two images? Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-01-23 18:03 -0800
        Re: Any quick, easy way to compare two images? Don Bruder <dakidd@sonic.net> - 2014-01-23 21:25 -0800
      Re: Any quick, easy way to compare two images? JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-01-23 16:31 -0500
        Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-23 16:57 -0500
          Re: Any quick, easy way to compare two images? JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-01-23 17:02 -0500
        Re: Any quick, easy way to compare two images? Don Bruder <dakidd@sonic.net> - 2014-01-23 21:28 -0800
      Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-23 16:32 -0500
        Re: Any quick, easy way to compare two images? Don Bruder <dakidd@sonic.net> - 2014-01-23 16:22 -0800
          Re: Any quick, easy way to compare two images? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-01-23 19:48 -0500
            Re: Any quick, easy way to compare two images? Don Bruder <dakidd@sonic.net> - 2014-01-23 23:54 -0800
              Re: Any quick, easy way to compare two images? Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-01-24 08:09 -0800
                Re: Any quick, easy way to compare two images? Don Bruder <dakidd@sonic.net> - 2014-01-24 08:44 -0800
          Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-23 22:06 -0500
            Re: Any quick, easy way to compare two images? Don Bruder <dakidd@sonic.net> - 2014-01-23 23:37 -0800
  Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-23 20:46 +0000
  Re: Any quick, easy way to compare two images? Lewis <g.kreme@gmail.com.dontsendmecopies> - 2014-01-23 23:19 +0000
    Re: Any quick, easy way to compare two images? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-01-23 18:38 -0500
      Re: Any quick, easy way to compare two images? Lewis <g.kreme@gmail.com.dontsendmecopies> - 2014-01-24 00:49 +0000
        Re: Any quick, easy way to compare two images? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-01-23 19:59 -0500
  Re: Any quick, easy way to compare two images? Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-01-23 15:25 -0800
    Re: Any quick, easy way to compare two images? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-01-23 18:37 -0500
      Re: Any quick, easy way to compare two images? Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-01-23 16:05 -0800
        Re: Any quick, easy way to compare two images? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-01-23 19:47 -0500
          Re: Any quick, easy way to compare two images? Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-01-23 17:10 -0800
            Re: Any quick, easy way to compare two images? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-01-24 17:42 -0500
              Re: Any quick, easy way to compare two images? Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-01-24 16:42 -0800
                Re: Any quick, easy way to compare two images? Don Bruder <dakidd@sonic.net> - 2014-01-24 20:08 -0800
                Re: Any quick, easy way to compare two images? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-01-25 10:54 -0500
                Re: Any quick, easy way to compare two images? JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-01-25 15:31 -0500
                Re: Any quick, easy way to compare two images? Don Bruder <dakidd@sonic.net> - 2014-01-25 17:31 -0800
                Re: Any quick, easy way to compare two images? Michael Vilain <vilain@NOspamcop.net> - 2014-01-25 17:57 -0800
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-26 03:09 +0000
                Re: Any quick, easy way to compare two images? JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-01-25 23:02 -0500
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-26 05:04 +0000
                Re: Any quick, easy way to compare two images? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-01-25 10:58 -0500
                Re: Any quick, easy way to compare two images? Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-01-25 10:29 -0800
                Re: Any quick, easy way to compare two images? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-01-25 13:39 -0500
                Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-25 13:45 -0500
                Re: Any quick, easy way to compare two images? Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-01-25 13:27 -0800
                Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-25 16:30 -0500
                Re: Any quick, easy way to compare two images? Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-01-25 13:33 -0800
                Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-25 16:52 -0500
                Re: Any quick, easy way to compare two images? JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-01-25 17:31 -0500
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-25 22:35 +0000
                Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-25 17:49 -0500
                Re: Any quick, easy way to compare two images? Tom Stiller <clusterfux.upmon@gmail.com> - 2014-01-25 22:55 +0000
                Re: Any quick, easy way to compare two images? JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-01-25 18:33 -0500
                Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-25 19:42 -0500
                Re: Any quick, easy way to compare two images? Don Bruder <dakidd@sonic.net> - 2014-01-25 17:38 -0800
                Re: Any quick, easy way to compare two images? JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-01-25 22:50 -0500
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-26 02:49 +0000
                Re: Any quick, easy way to compare two images? Lewis <g.kreme@gmail.com.dontsendmecopies> - 2014-01-26 14:21 +0000
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-26 15:17 +0000
                Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-26 14:04 -0500
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-26 00:17 +0000
                Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-25 19:42 -0500
                Re: Any quick, easy way to compare two images? dorayme <do_ray_me@bigpond.com> - 2014-01-26 12:23 +1100
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-26 02:54 +0000
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-26 02:52 +0000
                Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-25 22:10 -0500
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-26 03:32 +0000
                Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-25 22:55 -0500
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-26 05:02 +0000
                Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-26 14:04 -0500
                Re: Any quick, easy way to compare two images? Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-01-25 18:03 -0800
                Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-25 22:10 -0500
                Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-25 17:49 -0500
                Re: Any quick, easy way to compare two images? Savageduck <savageduck1@{REMOVESPAM}me.com> - 2014-01-25 15:59 -0800
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-26 00:24 +0000
                Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-25 19:42 -0500
                Re: Any quick, easy way to compare two images? Savageduck <savageduck1@{REMOVESPAM}me.com> - 2014-01-25 17:30 -0800
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-26 02:57 +0000
                Re: Any quick, easy way to compare two images? JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-01-25 22:46 -0500
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-26 03:49 +0000
                Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-25 22:55 -0500
                Re: Any quick, easy way to compare two images? dorayme <do_ray_me@bigpond.com> - 2014-01-26 12:08 +1100
                Re: Any quick, easy way to compare two images? Savageduck <savageduck1@{REMOVESPAM}me.com> - 2014-01-25 17:31 -0800
                Re: Any quick, easy way to compare two images? dorayme <do_ray_me@bigpond.com> - 2014-01-26 13:00 +1100
                Re: Any quick, easy way to compare two images? Don Bruder <dakidd@sonic.net> - 2014-01-25 20:13 -0800
                Re: Any quick, easy way to compare two images? dorayme <do_ray_me@bigpond.com> - 2014-01-26 16:15 +1100
                Re: Any quick, easy way to compare two images? Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-01-25 18:07 -0800
                Re: Any quick, easy way to compare two images? Savageduck <savageduck1@{REMOVESPAM}me.com> - 2014-01-25 18:24 -0800
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-26 02:58 +0000
                Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-25 22:10 -0500
                Re: Any quick, easy way to compare two images? Don Bruder <dakidd@sonic.net> - 2014-01-25 17:36 -0800
                Re: Any quick, easy way to compare two images? Savageduck <savageduck1@{REMOVESPAM}me.com> - 2014-01-25 17:51 -0800
                Re: Any quick, easy way to compare two images? Don Bruder <dakidd@sonic.net> - 2014-01-26 00:39 -0800
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-26 15:43 +0000
                Re: Any quick, easy way to compare two images? Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-01-26 08:19 -0800
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-26 16:31 +0000
                Re: Any quick, easy way to compare two images? Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-01-26 09:54 -0800
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-26 18:14 +0000
                Re: Any quick, easy way to compare two images? Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-01-26 10:44 -0800
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-26 19:10 +0000
                Re: Any quick, easy way to compare two images? dorayme <do_ray_me@bigpond.com> - 2014-01-27 11:14 +1100
                Re: Any quick, easy way to compare two images? Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-01-26 16:22 -0800
                Re: Any quick, easy way to compare two images? dorayme <do_ray_me@bigpond.com> - 2014-01-27 11:44 +1100
                Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-27 13:06 -0500
                Re: Any quick, easy way to compare two images? Lewis <g.kreme@gmail.com.dontsendmecopies> - 2014-01-27 12:48 +0000
                Re: Any quick, easy way to compare two images? Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-01-27 05:49 -0800
                Re: Any quick, easy way to compare two images? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-01-26 12:05 -0500
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-26 17:08 +0000
                Re: Any quick, easy way to compare two images? Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-01-26 12:27 -0500
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-26 17:37 +0000
                Re: Any quick, easy way to compare two images? JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-01-26 15:36 -0500
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-26 21:46 +0000
                Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-26 14:04 -0500
                Re: Any quick, easy way to compare two images? Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-01-26 12:16 -0800
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-26 21:47 +0000
                Re: Any quick, easy way to compare two images? Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-01-26 16:21 -0800
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-27 01:57 +0000
                Re: Any quick, easy way to compare two images? Don Bruder <dakidd@sonic.net> - 2014-01-26 10:32 -0800
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-26 18:54 +0000
                Re: Any quick, easy way to compare two images? JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-01-26 15:40 -0500
                Re: Any quick, easy way to compare two images? Savageduck <savageduck1@{REMOVESPAM}me.com> - 2014-01-26 13:30 -0800
                Re: Any quick, easy way to compare two images? Don Bruder <dakidd@sonic.net> - 2014-01-26 15:06 -0800
                Re: Any quick, easy way to compare two images? JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-01-26 18:20 -0500
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-26 23:35 +0000
                Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-27 13:06 -0500
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-27 19:14 +0000
                Re: Any quick, easy way to compare two images? JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-01-27 23:18 -0500
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-28 04:27 +0000
                Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-29 14:01 -0500
                Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-29 14:01 -0500
                Re: Any quick, easy way to compare two images? john hevelin <bwotte@panix.com> - 2014-01-27 01:19 +0000
                Re: Any quick, easy way to compare two images? Don Bruder <dakidd@sonic.net> - 2014-01-26 18:28 -0800
                Re: Any quick, easy way to compare two images? john hevelin <bwotte@panix.com> - 2014-01-28 02:26 +0000
                Re: Any quick, easy way to compare two images? Don Bruder <dakidd@sonic.net> - 2014-01-28 06:35 -0800
                Re: Any quick, easy way to compare two images? dorayme <do_ray_me@bigpond.com> - 2014-01-27 10:55 +1100
                Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-25 22:10 -0500
                Re: Any quick, easy way to compare two images? Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-01-25 21:41 -0800
                Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-26 14:04 -0500
                Re: Any quick, easy way to compare two images? Jolly Roger <jollyroger@pobox.com> - 2014-01-26 03:13 +0000
                Re: Any quick, easy way to compare two images? JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-01-25 17:30 -0500
                Re: Any quick, easy way to compare two images? john hevelin <bwotte@panix.com> - 2014-01-25 18:51 +0000
                Re: Any quick, easy way to compare two images? Lewis <g.kreme@gmail.com.dontsendmecopies> - 2014-01-25 19:06 +0000
                Re: Any quick, easy way to compare two images? JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-01-25 15:37 -0500
                Re: Any quick, easy way to compare two images? JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-01-25 15:35 -0500
        Re: Any quick, easy way to compare two images? nospam <nospam@nospam.invalid> - 2014-01-23 22:06 -0500

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