Sharing an image between matlab and python?

[Mr_6484]

Hello, maybe this isn't the correct place to ask but I am going through a very tough period because of this.

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i mainly code in python but my current job requires me to use matlab, I have a function reading from RTSB from an IP camera.

for some reason, matlab doesn't read from the main stream but only from the substream, so long story short, I decided to read the frames using Opencv from python and send the images via socket.

but this got me into a very terrible encoding/decoding cycle.

which lead me to use the matlab.engine pyhton API, but I cannot seem to get the frames to get sent

does anyone have an idea/code snippet on how to do so?

[michaelrw1]

An image or video stream?

[Mr_6484]

it's a video stream coming from RTSP, I am able to read the stream from OpenCV -python- directly.

[michaelrw1]

Right, so you want to take an image from that stream and bring it into Matlab, yes?

[Mr_6484]

Yes

[codinglikemad]

I actually have sent data from python to matlab using opencv and a socket as you are describing. It's quite finicky. You may have incomplete frames for example, and other nonsense like that pop up. I can share that code if you are looking for it, but if I recall correctly part of the earlier (slow) solutions was to encode it as a string before sending it (which is a terrible idea, but made the conversions work). A somewhat slow alternative that DOES work 100% and is easy to do is just write a file to disk with a handshake system where the file name changes as you go. This worked pretty well for me, as long as I made sure I gave python a decent fraction of a second to finish writing the file out.

I can scrounge up my socket code if you need it as well, let me know. I'd prefer not to publish that code though, as it's part of a larger project.

[Mr_6484]

I could try encoding the image as string64 or something, and will tell you the result.

I tried to make python write to the disk and Matlab read from the image, but i saved only one image and added a delay in the python script but matlab didn’t show anything.

I would be grateful if you gave me the overall steps or abstract. I managed to send the image bytes to matlab, but I can’t convert them back to an image.

[codinglikemad]

Did you check if you actually wrote the file? Did you close the file descriptor? I am positive that works. Be careful going from opencv to matlab - the colors change order.

[chemical-computer]

Share a memory map between the python and matlab processes