Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.sys.mac.system > #55228
| From | nospam <nospam@nospam.invalid> |
|---|---|
| Newsgroups | comp.sys.mac.system |
| Subject | Re: Any quick, easy way to compare two images? |
| Date | 2014-01-23 16:32 -0500 |
| Organization | A noiseless patient Spider |
| Message-ID | <230120141632457449%nospam@nospam.invalid> (permalink) |
| References | <lbrnpr$q5o$1@dont-email.me> <230120141424174937%nospam@nospam.invalid> <lbrvrh$7ua$1@dont-email.me> |
In article <lbrvrh$7ua$1@dont-email.me>, Don Bruder <dakidd@sonic.net>
wrote:
> > also keep in mind that the camera won't produce pixel identical results
> > on every frame, even when nothing has changed,
>
> That alone could be used to tell me "This is a new image". I don't care
> if the content of the image has changed, or how, or by how much - I only
> care that the two images either are, or are not, two copies of the same
> image.
>
> Lemme clarify...
> The source I'm using obviously runs a loop something along the lines of
> "wake up, get an image from the camera, turn it into a JPG file, and
> stick it someplace on the server so the world can get to it, then go to
> sleep for a while". The problem is that "for a while" isn't a stable
> value - Sometimes it's once per minute, sometimes once per 62 seconds,
> sometimes once per second, sometimes once per hour, with no indication
> of what condition(s) make it vary. I want to grab every available image,
> but NOT grab umpty-nine copies of an image that's been sitting there for
> who-knows-how-long
>
> > so you can't just loop
> > through all pixels and compare. the values will vary slightly.
>
> I don't see why not - Like I said above, I don't care if the *image
> content* changes - only that "the image" I get is or is not the same one
> I got the last time I grabbed it.
light is random and cameras have a small amount of noise, so each frame
will be slightly different than the previous one, even if nothing has
changed in the scene.
one frame might have a pixel that's {50,100,150} and the next time it's
{51,98,151} and the time after that it's {48,101,153}. that will fail
an equality test even though the images are identical. the brighter the
scene the more it can vary.
completely cover the lens so that no light hits the sensor at all and
the pixels will change slightly from frame to frame (and none will be
{0,0,0} either). there is always going to be some noise.
the difference is below the limits of human perception and you won't
notice it.
Back to comp.sys.mac.system | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll 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
csiph-web