Contents
imagehub is a part of a distributed computer vision system that runs on multiple computers. The minimal system is one Raspberry Pi running imagenode and one larger computer (such as a Mac) running imagehub. You can see the overall design of such a system in the yin-yang-ranch Github repository Yin Yang Ranch project. imagehub is dependent on having working copies of imagezmq on both the RPi computer and the display computer. Be sure to set up and test both imagezmq and imagenode BEFORE you try to install and test imagehub. The instructions for installing and testing imagezmq are in the imagezmq GitHub repository. The instructions for installing and testing imagenode are in the imagenode GitHub repository.
Running the tests below will place 3 new directories on the computer running
imagenode: (1) a logs directory and (2) an images directory, both of
which are subdirectories of (3) an imagehub_data directory. This directory
name can be changed using the data_directory option in the the
imagehub.yaml file.
To run the tests, imagehub should be git-cloned to the computer that it will be running on. I have done all testing using the user's home directory:
~ # user home directory +--- imagehub.yaml # copied from example.yaml file & edited as needed | +--- imagehub # the git-cloned directory for imagehub | +--- docs | +--- imagehub | +--- imagehub.py
The first test runs the sending program imagenode on an RPi and the receiving program imagehub on a mac (typically the same one you used as a display computer when you tested imagenode).
Clone the imagenode GitHub repository onto your mac in your home directory:
git clone https://github.com/jeffbass/imagehub.git
Open 2 terminal windows on your Mac. One will be used for running imagehub and the other will be used for running imagenode on a Raspberry Pi.
In one terminal window, copy
imagehub/imagehub.yamltoimagehub.yamlin the home directory (~) using the command below. You will not need to edit the yaml file. The name of the file in the home directory must beimagehub.yamlfor this test:cp ~/imagehub/imagehub.yaml ~/imagehub.yaml
In the same terminal window, change to the
~/imagehub/imagehubdirectory. You will be running imagehub.py from here in a few more steps:cd ~/imagehub/imagehub
In the same terminal window, run the program
imagehub.pyand leave it running:workon py3cv3 # my virtualenv name; use yours instead python imagehub.py
In the other terminal window, log in to the Raspberry Pi that you will be using to run imagenode. This will probalby be the same Raspberry Pi that you tested imagenode on. Change to the imagenode program directory and run the imagenode program as you did during testing. NOTE: You will want to change the "send_frames" option in the ~/imagenode.yaml file on the Raspberry Pi to "detected event", or else you will save thousands of images that will be sent if the "send_frames" option is set to "continuous" as it was when you tested imagenode:
cd ~/imagenode/imagenode python imagenode.py
Move something or change the lighting in the ROI area of the imagenode PiCamera. When you tested imagenode using an imagezmq test program as a hub you created motion or changed lighting. Do the same for this test.
You won't see anything happen...remember, all that imagehub does is receive and save the event messages and images being sent by imagenode. So, after a few minutes of "creating events" in front of the camera, you can stop both programs by pressing Ctrl-C in both terminal windows.
If you look in the imagehub_data directory you will see some files that
contain the images and the event messages from your imagenode PiCamera. They
will look something like this:
~/imagehub_data ├── images │ └─── 2018-12-30 # this will be named for the date of your testing │ ├── YourNodeName-2020-12-30T23.13.31.620992.jpg │ ├── YourNodeName-2020-12-30T23.13.31.813029.jpg │ └── # etc, etc. for additional images │ └── logs └─── imagehub.log # contains event messages created by your testing
Images created by your motion or light changes will be named according to your node "name" option in the ~/imagenode.yaml file on the Raspbery Pi. You can use any image viewer to look at these jpg images.
If you view the imagehub.log file, you will see an event listing that looks
like the log example in the beginning of the README.rst file.
Remember, when running the tests, start the imagehub program running first, and then start the imagenode program. You can end the programs by pressing Ctrl-C in each terminal window.
The second test should be run with 2 Raspberry Pi's running imagenode, with both of them simultaneously sending event messages and images to imagehub. Run this test the same way as Test 1, but open a third terminal window in which to start imagenode running on a 2nd Raspberry Pi with a PiCamera.
- In one terminal window on the Mac, start the imagehub program running.
- In a second terminal window on the Mac, ssh into one of the Raspberry Pi computers and start imagenode.
- In a third terminal window on the Mac, ssh into a different Raspberry Pi computer and start imagenode.
- Make motion or light changes in front of the PiCameras to create events.
The images and log items saved by this test will add cumulatively to the ones saved in Test 1, so you will see all the images from Test 1 AND all the images from Test 2 in the images directory. And the event messages in the log will be added to the ones put into the log during Test 1.
It is important that the node "name" option specifies a DIFFERENT node name for each Raspberry Pi imagenode (in the ~/imagenode.yaml file on each RPi). The node name becomes part of the file name of each image and it labels each event in the log. Each imagenode name must be unique for this naming convention to work.
There are a few settings in the imagehub.yaml file that specify the data
directory, a maximum number of images to write, etc. You can learn more about
these options in ImageHub Settings and the imagehub.yaml file.