Adjusting my motion tuning - trying to understand stats...

[JimS]

I am getting a huge amount of events so knuckled down and dug through some documentation and primarily the Understanding zoneminder's zoning system for dummies. I made a first attempt at settings and still see a lot of false alarms. One thing that puzzles me is blobs trailing the area of motion. The previous frames don't have motion in those areas. I am guessing there are slight variations in the pixels (maybe from water moving as it was lightly raining or reflections from the car moving?) and perhaps should raise the pixel threshold? Is there any way to see the actual pixel change for specific pixels or areas to get some idea of a realistic setting? I was going to post two adjacent frames but it's not obvious how to do that. I tried putting image tags and then just pasting but that didn't seem to work. I tried to locate some notes on how to do it on this forum and found a read this before posting message but it was for a very old version of zm and all the links were broken - is there a more modern place to find basic stuff? I will post some details of settings and images once I figure that out.

[JimS]

I see that images can be inserted using the attachment tab below the main window so will try that...
Here are two consecutive frames. When I look at stats some frames have two lines - an unnamed zone and one that I named. What's with the unnamed zone? I don't always see it in the stats so it must be something about the images that sometimes generates the unnamed one?
Had a bit of trouble making the stats columns like up so end up doing them as text without tabs and putting them in a code box. There is probably a better way to do this...

Code: Select all

stats for frame 80
Zone  Pixel Diff  Alarm Px    Filter Px   Blob Px   Blobs Blob Sizes        Alarm Limits    Score
         64      40666 (0%)   34397 (0%) 32287 (0%)  2   8038-24249 (0%-0%)  190,144-626,300 10
Parking  55      52074 (19%) 42638 (15%) 26829 (9%)  1   26829 (9%)          178,144-626,272 9

Frame 81
Zone  Pixel Diff  Alarm Px    Filter Px   Blob Px   Blobs Blob Sizes  Alarm Limits    Score
         64      39787 (0%)   33969 (0%)  31896 (0%)  1   31896 (0%)  209,144-637,299 10
Parking  55     51168 (18%)   41909 (15%) 37753 (13%) 1   37753 (13%) 170,144-637,309 13

I started by drawing a zone for what I figured was a small car at the farthest distance and the pixels for that was 1500 so used that for my settings and didn't keep that as a zone. Looks like I need to increase the minimums for an event but want to better understand things. Also will adjust the buffer alarm frame count to avoid single frame triggers - thinking about 3 - 5.

Main question is why I have the large areas outlined in red where there doesn't seem to be any changes in that area for many previous frames.

Settings.PNG (643.86 KiB) Viewed 3143 times

11_484725_80.jpg (63.4 KiB) Viewed 3143 times

11_484725_81.jpg (64.23 KiB) Viewed 3143 times

[JimS]

Still have a bunch of questions but think I found a couple answers.

The blobs trailing is from "reference image blend" which blends frames into the reference image as a percentage so a number of frames make up the reference image.

I found that some of my alarm frames didn't have statistics. That's because I have the alarm frame count greater than 1. This causes the first frames to not have statistics.

I think I have this right but would be good if someone could confirm it. Any tips on this would be appreciated. Still wondering why some frames have multiple lines of statistics.