streamlitapp.py

import streamlit as st
import base64
import io
import requests,json
from PIL import Image
import cv2
import numpy as np
import matplotlib.pyplot as plt
import requests
import random

# use file uploader object to recieve image
# Remember that this bytes object can be used only once
def bytesioObj_to_base64str(bytesObj):
	return base64.b64encode(bytesObj.read()).decode("utf-8")

# Image conversion functions

def base64str_to_PILImage(base64str):
	base64_img_bytes = base64str.encode('utf-8')
	base64bytes = base64.b64decode(base64_img_bytes)
	bytesObj = io.BytesIO(base64bytes)
	img = Image.open(bytesObj) 
	return img

def PILImage_to_cv2(img):
	return np.asarray(img)

def ImgURL_to_base64str(url):
    return base64.b64encode(requests.get(url).content).decode("utf-8")

def drawboundingbox(img, boxes,pred_cls, rect_th=2, text_size=1, text_th=2):
    img = PILImage_to_cv2(img)
    class_color_dict = {}
    
    #initialize some random colors for each class for better looking bounding boxes
    for cat in pred_cls:
        class_color_dict[cat] = [random.randint(0, 255) for _ in range(3)]
    
    for i in range(len(boxes)):
        cv2.rectangle(img, (int(boxes[i][0][0]), int(boxes[i][0][1])),
                      (int(boxes[i][1][0]),int(boxes[i][1][1])),
                      color=class_color_dict[pred_cls[i]], thickness=rect_th)
        cv2.putText(img,pred_cls[i], (int(boxes[i][0][0]), int(boxes[i][0][1])),  cv2.FONT_HERSHEY_SIMPLEX, text_size, class_color_dict[pred_cls[i]],thickness=text_th)
    plt.figure(figsize=(20,30))
    plt.imshow(img)
    plt.xticks([])
    plt.yticks([])
    plt.show()

st.markdown("<h1>Our Object Detector App using FastAPI</h1><br>", unsafe_allow_html=True)

bytesObj = st.file_uploader("Choose an image file")

st.markdown("<center><h2>or</h2></center>", unsafe_allow_html=True)

url = st.text_input('Enter URL')

if bytesObj or url:
	# In streamlit we will get a bytesIO object from the file_uploader 
	# and we convert it to base64str for our FastAPI
	if bytesObj:
		base64str = bytesioObj_to_base64str(bytesObj)
	
	elif url:
		base64str = ImgURL_to_base64str(url)

	# We will also create the image in PIL Image format using this base64 str
	# Will use this image to show in matplotlib in streamlit
	img = base64str_to_PILImage(base64str)
		
	# Run FastAPI 
	payload = json.dumps({
	  "base64str": base64str,
	  "threshold": 0.5
	})

	response = requests.put("http://18.237.28.174/predict",data = payload)
	data_dict = response.json()


	st.markdown("<center><h1>App Result</h1></center>", unsafe_allow_html=True)
	drawboundingbox(img, data_dict['boxes'], data_dict['classes'])
	st.pyplot()
	st.markdown("<center><h1>FastAPI Response</h1></center><br>", unsafe_allow_html=True)
	st.write(data_dict)