Cached data after using st.camera_input()?


Share a clear and concise description of the issue. Aim for 2-3 sentences.

original post:

Not sure where the captured camera image is stored locally or cached? Can I extract the image from a file path?

Steps to reproduce

Code snippet:

def main():
    """A simple ID wine"""
    #Title of the app
    st.title("wine BAKER app with streamlit + Camera Preview")
    st.subheader("streamlit is :fire:")

    img_file_buffer = st.camera_input("一二三,🍆 ")

    if img_file_buffer is not None:
        # To read image file buffer with OpenCV:
        bytes_data = img_file_buffer.getvalue()
        cv2_img = cv2.imdecode(np.frombuffer(bytes_data, np.uint8), cv2.IMREAD_COLOR)

        # Check the type of cv2_img:
        # Should output: <class 'numpy.ndarray'>

        # Check the shape of cv2_img:
        # Should output shape: (height, width, channels)


        #how to save captured camera input image
        """with open(, "wb") as f:

        st.success("File Saved")"""

    image ='cv2_img')
    st.image(image, caption='Cheese', use_column_width=False)

If applicable, please provide the steps we should take to reproduce the error or specified behavior.

Expected behavior:

Explain what you expect to happen when you run the code above.

Actual behavior:

Explain the undesired behavior or error you see when you run the code above.
If you’re seeing an error message, share the full contents of the error message here.

Debug info

  • Streamlit version: (get it with $ streamlit version)
  • Python version: (get it with $ python --version)
  • Using Conda? PipEnv? PyEnv? Pex?
  • OS version:
  • Browser version:

Requirements file

Using Conda? PipEnv? PyEnv? Pex? Share the contents of your requirements file here.
Not sure what a requirements file is? Check out this doc and add a requirements file to your app.


  • Link to your GitHub repo:
  • Link to your deployed app:

Additional information

If needed, add any other context about the problem here.

Where does st.camera_input camera captured file is being stored?

Streamlit holds information in memory until you explicitly write it somewhere. From the documentation:

picture = st.camera_input("Take a picture")

picture is just the image data held in memory, not saved as a file anywhere.

The example you posted works with the image in memory, changing the data type, but it’s still in memory. You can check out the imwrite method if you are looking to save the image as a file.

1 Like