Date: Tue, 2 Sep 2008 11:02:29 -0500 From: "Andrew Gould" <andrewlylegould@gmail.com> To: FreeBSD <freebsd@optiksecurite.com> Cc: Tom Marchand <m0rchand@comcast.net>, freebsd-questions@freebsd.org Subject: Re: How to compare 2 images from command line Message-ID: <d356c5630809020902w2f633155w571811ad844a4d1f@mail.gmail.com> In-Reply-To: <48BD5C65.9030502@optiksecurite.com> References: <090220081512.17537.48BD57E100051D800000448122068246930B020E080C9DCF03@comcast.net> <48BD5A8A.5080400@optiksecurite.com> <d356c5630809020828y1e4bf347k7725857a4ceaa761@mail.gmail.com> <48BD5C65.9030502@optiksecurite.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Tue, Sep 2, 2008 at 10:31 AM, FreeBSD <freebsd@optiksecurite.com> wrote: > Andrew Gould a =E9crit : > >> >> >> On Tue, Sep 2, 2008 at 10:23 AM, FreeBSD <freebsd@optiksecurite.com<mail= to: >> freebsd@optiksecurite.com>> wrote: >> >> Tom Marchand a =E9crit : >> >> Hash the images and compare the hashes. >> >> -------------- Original message ---------------------- >> From: FreeBSD <freebsd@optiksecurite.com >> <mailto:freebsd@optiksecurite.com>> >> >> Hi everyone, >> >> I'm trying to determine if 2 jpeg images are identical. The >> images are screenshots taken with scrot at different times. >> The point is to know if the display is working correctly. I >> tried to use 'diff' but without success, probably because of >> the metadata included in the image. I also tried the >> 'compare' command from imagemagick, but it produce an image >> containing the difference between the 2 images instead of >> telling me if both images are identical. >> >> So, my question is what are you using to determine if 2 >> images are identical? >> >> I'm using FreeBSD 7.0 and I need to be able to script this >> comparaison for an integration in Nagios. >> >> Thank you, >> >> Martin >> >> >> I just tried it and it doesn't work. The hashes are different. I can'= t >> say that I'm surprised since 'diff' is "seeing" a difference between >> the >> two identical images. >> >> >> Thanks for the suggestion >> >> >> Yes, there's a huge difference between testing differences in images and >> testing differences in files. What do you mean by "...know if the displ= ay >> is working correctly."? >> >> Andrew >> > > I want to determine if Mplayer is working correctly. The best way to be > sure is to check if the display on the screen is changing. That's the > purpose of the screenshots. The screenshots are taken by Nagios every 5 > minutes and the new screenshot is compared with the preceding one. But, b= y > now, it doesn't work because every tool we try is seeing a diffence betwe= en > 2 identical images. > > Thank you for your interest > Are you simply trying to determine whether the mplayer has finished playing a movie (that you're not watching)? It seems to me that the fact that the image changes is not a good indication that mplayer is "working correctly", only that the movie isn't running.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?d356c5630809020902w2f633155w571811ad844a4d1f>