Preview MJPEG Stream on a Ricoh Theta X with Python and OpenCV

I have a live MJPEG preview running over a USB-C ethernet adapter to the Ricoh Theta X.
Here is a screen shot of the preview running from Visual Studio Code:

Screen Shot of Live Preview for Ricoh Theta X

Written in Phyton using OpenCV to display the MJPEG stream.

#Begin Phyton Code
import requests
from requests.auth import HTTPDigestAuth
import cv2
import numpy as np

url = http://[Camera IP Address]/osc/commands/execute
username = "CameraSerialNumber"
password = "DigitsOnlyofCameraSerialNumber"

payload = {
    "name": "camera.getLivePreview"

headers = {
    "Content-Type": "application/json;charset=utf-8"

response =, auth=HTTPDigestAuth(username, password), json=payload, headers=headers, stream=True)

if response.status_code == 200:
    bytes_ = bytes()
    for chunk in response.iter_content(chunk_size=1024):
        if chunk:
            bytes_ += chunk
            a = bytes_.find(b'\xff\xd8')
            b = bytes_.find(b'\xff\xd9')
            if a != -1 and b != -1:
                jpg = bytes_[a:b+2]
                bytes_ = bytes_[b+2:]
                img = cv2.imdecode(np.fromstring(jpg, dtype=np.uint8), cv2.IMREAD_COLOR)
                cv2.imshow("Preview", img)
                if cv2.waitKey(1) == 27:
    print("Error: ", response.status_code)

#End Python Code

Wow, this is fantastic. Thanks for sharing it!

We’d like to give you a small thanks for your contribution to the community with a community thanks award. I’ll send you an email with more info.

I have this working very beautifully and very smoothly with a THETA V

1 Like

Looking good! I’m working on converting this to .NET as well. Having a bit of difficulty with the CV2 in .net. Happy to share the code I have so far if you want to take a crack at it.

The quality of the stream from OpenCV is better than most client implementations that I’ve seen. Your technique produces a nice result. I made a video of the video stream so that other people can easily see the quality of the camera → computer stream.

I’ve only used C# with Unity, so I’m not sure I’d be of any help. However, I could test it on my Windows 11 laptop. It’s possible other people may be able to provide assistance.

The python OpenCV technique is pretty cool. I’m going to try some transformations with OpenCV and build a simple GUI for the Python script to make it more fun for people in my office to play around with it.

Right on. I’ll keep working on the .net version. If I get it working will share the code with you.

Bob Katter

1 Like

now with Canny edge detection.



# showWindow 1: normal view
# showWindow 2: canny edge detection
showWindow = 2
  if (showWindow == 1):
      cv2.imshow("Preview", img)

  if (showWindow == 2):
      # Convert to graycsale
      img_gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
      # Blur the image for better edge detection
      img_blur = cv2.GaussianBlur(img_gray, (3,3), 0) 
      # Canny Edge Detection
      edges = cv2.Canny(image=img_blur, threshold1=100, threshold2=200) # Canny Edge Detection
      # Display Canny Edge Detection Image
      cv2.imshow('Canny Edge Detection', edges) 

That is cool. I’ll have to play around with that. I’m also looking into using CV2 to stitch our images together as I’ve been looking for a better method than we currently use., which does work well. Here is an example of what we use the 360 cameras for.



1 Like