can't read an image uploaded with st.file_uploader()

I get my hand on the new feature that we all have been waiting for.

I tested it to upload an image and read it with OpenCV (cv.VideoCapture) but unfortunately, I encounter an error. The type of the uploaded image is <_io.BytesIO object at 0x7f4c7adc7db0>

Error message

TypeError: an integer is required (got type _io.BytesIO)
Traceback:
  File "/usr/local/lib/python3.6/site-packages/streamlit/ScriptRunner.py", line 324, in _run_script
    exec(code, module.__dict__)
  File "/workspaces/inveesion/main.py", line 767, in <module>
    cap = Config().input_output_data(guiParam)
  File "/workspaces/inveesion/main.py", line 508, in input_output_data
    cap = cv.VideoCapture(file_path)

[kantuni]

Dear @robmarkcole,

You need to check that img_file_buffer is not None before trying to Image.open() it. Otherwise, you will get an AttributeError.

import streamlit as st
import numpy as np
from PIL import Image

img_file_buffer = st.file_uploader("Upload an image")
if img_file_buffer is not None:
    image = Image.open(img_file_buffer)
    img_array = np.array(image) # if you want to pass it to OpenCV
    st.image(image, caption="The caption", use_column_width=True)

P.S. Thanks for the suggested example!

[robmarkcole]

Edit - just noticed this thread with solution https://discuss.streamlit.io/t/png-bytes-io-numpy-conversion-using-file-uploader/1409/2

Suggested example for the docs:

import streamlit as st
from PIL import Image
import numpy as np

img_file_buffer = st.file_uploader("Upload an image", type=["png", "jpg", "jpeg"])

image = Image.open(img_file_buffer)
img_array = np.array(image)

if image is not None:
    st.image(
        image,
        caption=f"You amazing image has shape {img_array.shape[0:2]}",
        use_column_width=True,
    )