Implementation

[mohan51]

how you implemented the imagenode in raspberrypi and what changes we need to do?I am testing this project using single raspberrypi as imagenode and my pc(linux os) as image hub.what changes do i need to do for running this project successfully using my resources?

[jeffbass]

The way to get started is with one Raspberry Pi (RPi) with Pi Camera sending images to one hub computer (Mac or Linux PC). It is easiest to start with the 2 computers on the same network. You can easily move them to different networks later. You do not need any other devices than a RPi with a camera (running imagenode.py) and a Linux PC (running imagehub.py). You will need networking hardware to connect the 2 computers, but it can be ethernet or WiFi.

So, start with 2 computers:

1. RPi computer running imagenode.py Note that imageZMQ is NOT yet tested with Raspberry Pi OS Bullseye. I am waiting for a production replacement for the Python PiCamera module. imageZMQ runs with Raspberry Pi OS Buster and earlier.
2. Linux PC running imagehub.py.

imageZMQ is a Python module that is imported by imagenode.py on the RPi and imported by imagehub.py on the Linux PC. So, imageZMQ must be running and tested on both the RPi and the Linux PC. imageZMQ is pip installable.

All the test programs and instructions are in imagezmq, imagenode and imagenub GitHub repositories. Here is the best way to get started:

1. On your Linux PC, get imageZMQ test programs running. See the imageZMQ documentation in the imageZMQ GitHub library.
2. Get imageZMQ test program 2 running with RPi sending and Linux PC receiving.
3. Only AFTER you have the imageZMQ test programs running OK should you attempt to use imagenode and imagehub programs
4. Run both the imagenode test programs for imagenode Test 1 on the same computer (it will need a screen, so use a Linux PC if you don’t have a screen on your RPi). Follow the instructions in the imagenode GitHub README file.
5. Run the imagenode test 2 and test 3 using an RPi as the imagenode and a Linux PC as the receiver.
6. Spend time experimenting with multiple settings in your imagenode.YAML file per the imagenode documentation. There are several example imagenode.yaml files in the imagenode repository.
7. Finally, run the test programs in the imagehub GitHub repository. You will then have a working setup that you can tune and adjust by changing imagenode.yaml settings.

I always use a virtual environment for running all tests and production programs. That is discussed in the imageZMQ, imagenode and imagehub documentation. I do all my testing running the programs with python at the command line. But in my production setup, I use systemctl / systemd. I always start the imagehub program BEFORE starting the imagenode program. My imagehub program typically runs for many months (on a laptop running Linux) without restarting, but the imagenodes restart more often than that.

I also run my prototype librarian.py on the same Linux laptop that is running imagehub.py. My prototype librarian answers queries by reading the imagehub log file. My librarian prototype program is in my yin-yang-ranch Github repository. I am continuing to develop my librarian prototype, but it is not yet ready for pushing to Github yet.

[mohan51]

for small poc can we neglect librarian and start to work on single node and single hub? and focus on transmitting the images?
Firstly i want to setup for motion detector with one raspberry pi and send the detected images to hub.? can i start with this poc?

[jeffbass]

Setting up a poc does not require a librarian program. Motion detection and temperature sensors on RPi computers are what I use in my production system.

Using a single RPi running imagenode sending images to a single imagehub computer works well. The imagehub computer should be a Mac or Linux PC with a SSD disk. Using an RPI for an imagehub will not work because writing image files to a micro SD card is slow and can cause SD card failure. I have found that sending jpg files from the imagenode is faster and does not slow down the network as much. There is an imagenode.yaml option that specifies the sending of jpg files. Raw OpenCV image files are quite large; jpg files are much smaller.

When you run this "imagenode to imagehub" arrangement, you will use the imagenode.yaml file on the RPi to specify the camera and motion detector settings as well as the IP address of the imagehub. You can specify the jpg option in the imagenode.yaml file. The description of the imagenode.yaml file is in this imagenode Github repository.

There is an imagehub.yaml file on the imagehub computer which specifies the location of the event log and the image files directories. The documentation about those directories and files is in the imagehub Github repository. If you specify the jpg option on the imagenode.yaml file, you must also specify the jpg option in the imagehub.yaml file. Raw OpenCV image files are quite large and take a lot of disk space; jpg files are much smaller. I use jpg files in my own production system.

You can use any program to read the log and the image files that accumulate on the imagehub computer. My own prototype librarian program is located in the yin-yang-ranch Github repository. It reads the imagehub event log while it is being actively written by the imagehub program. This has worked well for me and allows me to read the imagehub events log in real time. I use SMS texting to query the imagenode log for recent motion detection events. My prototype librarian is a poc for reading the imagehub events log and does not have any image reading or image analysis code in it yet. There are many image analysis programs in tutorials and Github repositories available. I am experimenting with some of them. But reading the imagehub event logs is my day to day use of my imagenode --> imagehub system.

[mohan51]

Hi Jeff,

We need to run imagezmq on both the node and hub?
because when ever i try to run imagezmq on hub side.its just running and exiting without calling any methods in the imagezmq.

[jeffbass]

I am not sure what you mean by "run imageZMQ on hub side".
imageZMQ is a Python module that is imported by a hub program on the hub computer. It is not a program that is run on the hub computer.
imageZMQ is also imported by a sending program on the image sending computer. It is not a program on the sending computer.
Before you can attempt running something such as an imagenode, it is important that you have imageZMQ test programs running correctly on both the image sending computer and the image receiving computer. The imageZMQ test programs are simple versions of the imagenode and imagehub programs.
Did you run the tests in the imageZMQ repository? I recommend that you run the first 3 tests described in the README of that repository in order. Which imageZMQ test programs did you run? Which test program failed? What was the error message, if any? If you have not been able to get the imageZMQ test programs running correctly, please open an issue in the imageZMQ repository and I will try to help you there.

[mohan51]

Hi Jeff, Imagezmq testcases an perfectly.but when i run (imagehub.py) in my linux and imagenode.py on rpi. they both are waiting and not executing anything. but imagenode should capture and sent to imagehub right? but the process is not happening

[mohan51]

while running imagenode
I am facing the below error

2023-06-12 12:15:51,966 ~ Starting imagenode.py
2023-06-12 12:15:52,027 ~ Unanticipated error with no Exception handler.
Traceback (most recent call last):
File "/home/vfvi/img/imagenode/imagenode/imagenode.py", line 30, in main
node = ImageNode(settings) # start ZMQ, cameras and other sensors
File "/home/vfvi/img/imagenode/imagenode/tools/imaging.py", line 109, in init
self.setup_cameras(settings)
File "/home/vfvi/img/imagenode/imagenode/tools/imaging.py", line 268, in setup_cameras
cam = Camera(camera, settings.cameras, settings) # create a Camera instance
File "/home/vfvi/img/imagenode/imagenode/tools/imaging.py", line 863, in init
self.cam = VideoStream(usePiCamera=True,
File "/home/vfvi/img/env/lib/python3.9/site-packages/imutils/video/videostream.py", line 13, in init
from .pivideostream import PiVideoStream
File "/home/vfvi/img/env/lib/python3.9/site-packages/imutils/video/pivideostream.py", line 2, in
from picamera.array import PiRGBArray
ModuleNotFoundError: No module named 'picamera'
2023-06-12 12:15:52,031 ~ Exiting imagenode.py
2023-06-12 12:15:52,032 ~ SIGTERM detected, shutting down

[jeffbass]

I'm glad you got the imageZMQ tests cases to work. Thanks for sending the imagenode.py error messages.

Did you send images for imageZMQ tests using a PiCamera? That's the default in the imageZMQ tests 2 and 3. I presume you were able to send camera images and that you saw them on your hub PC OK? That would test that your camera was working OK on your imagenode computer. You need to run the imageZMQ tests on the same imagenode RPi computer and imagehub PC computer that will be running imagenode.py.

Your error message indicates that imagenode.py is not successfully importing the picamera module. Are you using a virtual environment? Did you do a pip install of picamera into that virtual environment? If you ran the imageZMQ tests using the picamera module OK, then you may be running imagenode.py in a different virtual environment or with a different linux path. Make sure you can import picamera correctly before you start imagenode.py. I find it helps to run Python from the command line in the same directory and virtual environment to verify that the import of picamera works OK. If you are using a USB camera instead of a picamera, you can specify that as an option for imagenode.py.

[mohan51]

Hi Jeff, I resolved the Picamera issue but could you please suggest the changes i need to do on imaging.py side.
should i need to comment the sensors? what changes do you suggest for making one hub and one node.

1. and also can i print the framerate? what is the usual frame rate for this? I am using raspberry pi 3 camera 5mp

[mohan51]

getting error from imagenode like "Exception at sender.send_jpg in REP_watcher function".

I running the programs in Virtual environment only

[mohan51]

I don't have any sensors.should i need any sensors for running the poc?

[mohan51]

Exception at sender.send_jpg in REP_watcher function.
--- Logging error ---
Traceback (most recent call last):
File "/home/vfvi/img/imagenode/imagenode/tools/imaging.py", line 344, in send_jpg_frame_REP_watcher
hub_reply = self.sender.send_jpg(text, jpg_buffer)
File "/home/vfvi/img/env/lib/python3.9/site-packages/imagezmq/imagezmq.py", line 162, in send_jpg_reqrep
hub_reply = self.zmq_socket.recv() # receive the reply message
File "zmq/backend/cython/socket.pyx", line 805, in zmq.backend.cython.socket.Socket.recv
File "zmq/backend/cython/socket.pyx", line 841, in zmq.backend.cython.socket.Socket.recv
File "zmq/backend/cython/socket.pyx", line 194, in zmq.backend.cython.socket._recv_copy
File "zmq/backend/cython/checkrc.pxd", line 13, in zmq.backend.cython.checkrc._check_rc
File "/home/vfvi/img/imagenode/imagenode/tools/utils.py", line 55, in clean_shutdown_when_killed
sys.exit()
SystemExit

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/home/vfvi/img/imagenode/imagenode/imagenode.py", line 38, in main
hub_reply = node.send_frame(text, image)
File "/home/vfvi/img/imagenode/imagenode/tools/imaging.py", line 347, in send_jpg_frame_REP_watcher
self. fix_comm_link()
File "/home/vfvi/img/imagenode/imagenode/tools/imaging.py", line 430, in fix_comm_link
self.shutdown_imagenode()
File "/home/vfvi/img/imagenode/imagenode/tools/imaging.py", line 449, in shutdown_imagenode
sys.exit()
SystemExit

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/usr/lib/python3.9/logging/handlers.py", line 73, in emit
if self.shouldRollover(record):
File "/usr/lib/python3.9/logging/handlers.py", line 192, in shouldRollover
self.stream.seek(0, 2) #due to non-posix-compliant Windows feature
RuntimeError: reentrant call inside <_io.BufferedWriter name='/home/vfvi/img/imagenode/imagenode/imagenode.log'>
Call stack:
File "/home/vfvi/img/imagenode/imagenode/imagenode.py", line 62, in
main()
File "/home/vfvi/img/imagenode/imagenode/imagenode.py", line 43, in main
log.warning('SIGTERM was received.')
File "/usr/lib/python3.9/logging/init.py", line 1454, in warning
self._log(WARNING, msg, args, **kwargs)
File "/usr/lib/python3.9/logging/init.py", line 1585, in _log
self.handle(record)
File "/usr/lib/python3.9/logging/init.py", line 1595, in handle
self.callHandlers(record)
File "/usr/lib/python3.9/logging/init.py", line 1657, in callHandlers
hdlr.handle(record)
File "/usr/lib/python3.9/logging/init.py", line 948, in handle
self.emit(record)
File "/usr/lib/python3.9/logging/handlers.py", line 75, in emit
logging.FileHandler.emit(self, record)
File "/usr/lib/python3.9/logging/init.py", line 1183, in emit
StreamHandler.emit(self, record)
File "/usr/lib/python3.9/logging/init.py", line 1083, in emit
self.flush()
File "/usr/lib/python3.9/logging/init.py", line 1063, in flush
self.stream.flush()
File "/home/vfvi/img/imagenode/imagenode/tools/utils.py", line 54, in clean_shutdown_when_killed
logging.warning('SIGTERM detected, shutting down')
Message: 'SIGTERM detected, shutting down'
Arguments: ()

[mohan51]

I cloned picam-motion-test.yaml to imagenode.yaml, for this i need to do any changes on imaging.py side?

[mohan51]

and also you are giving default frame rate = 32, then how we need to calculate the fps from Rpi to hub(linux pc)?

[mohan51]

Hi Jeff, I successfully ran the motion detector, but how to calculate fps ? and also how to detect the motion in the images, because when i saw the imagehub logs i found the messages regarding still and motion but the hub receiving all the images.how to filter the motion images in the hub, when i studying your repo , I came to know that the images which is used for motion detection will send to hub? right?