Imgcomp makes motion triggered timelapses using a Raspberry Pi and camera module.

It serves a similar purpose as the software "motioneye", but operates on still frames
instead of video.  This makes for much better image detail, but frame rate is at
best 4 fps with a v1 camera module (v2 and hq modules are slower)

Images are initially captured to ramdisk to minimize flash wear, then analyzed and
if significant, saved to flash.

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Please see setup/setting_up.txt for how to set up.
There is also a "docs" directory with more information

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Assumed directory structure:
~/imgcomp/...           where imgcomp source files live.
~/imgcomp.conf          configuration file, imgcomp should run in this directory
						(typing imgcomp/imgcomp to run)
~/images/               Root directory for where the images go.
~/images/200204/        Root for pictures of Feb 4 2020 (one dir for each day,
                        named YYMMDD
~/images/200204/13/     Pictures for 1 pm to 2 pm for Feb 4 2020
~/images/200204/13/0204-131445 0494.jpg
                        Picture taken Feb 4 2020 at 13:14:45, change level 494
~/images/saved/         Where picture are hard linked to when "saved" from image
                        browser.  One directory for each month.

~/www                   web root
~/www/view.cgi          view.cgi is dropped here on compiling viewing program
~/www/realtime.html
~/www/wait_change.cgi
~/www/showpic.js        Also dropped here on compiling viewing program                        
~/www/pix/              links to ../../images (softlink)
~/www/browse.conf       configuration file, used for setting local holidays

Note that imgcomp can be configured for different directory structures,
but the html browser must use the above directory structure.

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IMGCOMP PROGRAM

To use imgcomp, you must compile it.  
There are sample configuration files in imgcomp/conf-examples
Imgcomp uses raspistill to dump files into /ramdisk (which is a ram disk)
Then reads and compares these files, copies them to ~/saved/.... if they
contain relevant changes.

In the video mode hack, it looks for video files in /ramdisk/vid and uses
ffmpeg to extract stills to /ramdisk/tmp then uses those files as input.
But if you want video, use the motionpi software instead.

Imgcomp uses the EXIF date in the file to figure out when the photos were
taken (not sure offhand if it will fall back to file date or current
date/time if there is no EXIF date in the pictures.

There is the imgcomp/setup directory which contains scripts that I use to
configure it to run on a raspberry pi, plus some scripts that are only
useful to me.  Also read file "imgcomp/setup/setting_up.txt"

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BROWSING PROGRAM

The browse program assumes images are stored in the www directory under
"pix", with a directory for each day, therein a directory for each hour.
For example, the pictures from noon to 1 pm on Jan 4 2020 would be in
    ~/www/pix/200104/13

Files in each directory are expected to be named:
    0104-130000 0002.jpg
    0104-130809 0002.jpg
    0104-130810 0941.jpg
    0104-130811 2102.jpg
    .....
    Log.html
    
First four digits are date of the year (excluding year)
Next six digits are time of day
Last four digits are change level.
Log.html is a log file that the browse tool can also display.
Imgcomp creates this directory structure to store its files as it saves them.

The main viewing program is "view.cgi", which does most of the work.
There is also the "tb.cgi" which is used to generate thumbnails on the fly,
very fast using libjpeg's built in undersampling.

wait_change.cgi is used for realtime.html to wait for a significant enough
change.  
showpic.js is the javascript code for flipping through the images.

Local holidays can be set in the browse.conf file in the format YYMMDD.
There is a sample configuration file in imgcomp/conf-examples.

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imgcomp is licensed under the GPL version 2 (not version 3)
For details, please see here: 
http://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation version 2
of the License.

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 (docs/license.txt)