app.py

import streamlit as st 
from PIL import Image 
from io import BytesIO 
import numpy as np 
import cv2

def convertto_watercolorsketch(inp_img):
	img_1 = cv2.edgePreservingFilter(inp_img, flags=2, sigma_s=50, sigma_r=0.8)
	img_water_color = cv2.stylization(img_1, sigma_s=100, sigma_r=0.5)
	return(img_water_color)

def pencilsketch(inp_img):
	img_pencil_sketch, pencil_color_sketch = cv2.pencilSketch(
		inp_img, sigma_s=50, sigma_r=0.07, shade_factor=0.0825)
	return(img_pencil_sketch)

def load_an_image(image):
	img = Image.open(image)
	return img

def main(): 
	st.title('WEB APPLICATION TO CONVERT IMAGE TO SKETCH')
	st.write("This is an application developed for converting " +
	"your ***image*** to a ***Water Color Sketch*** OR ***Pencil Sketch***")
	st.subheader("Please Upload your image")
	
	image_file = st.file_uploader("Upload Images", type=["png", "jpg", "jpeg"])

	if image_file is not None:
		option = st.selectbox('How would you like to convert the image',
							('Convert to water color sketch',
							'Convert to pencil sketch'))
		if option == 'Convert to water color sketch':
			image = Image.open(image_file)
			final_sketch = convertto_watercolorsketch(np.array(image))
			im_pil = Image.fromarray(final_sketch)
			col1, col2 = st.columns(2)
            
			with col1:
				st.header("Original Image")
				st.image(load_an_image(image_file), width=250)

			with col2:
				st.header("Water Color Sketch")
				st.image(im_pil, width=250)
				buf = BytesIO()
				img = im_pil
				img.save(buf, format="JPEG")
				byte_im = buf.getvalue()
				st.download_button(
					label="Download image",
					data=byte_im,
					file_name="watercolorsketch.png",
					mime="image/png"
				) 

		if option == 'Convert to pencil sketch':
			image = Image.open(image_file)
			final_sketch = pencilsketch(np.array(image))
			im_pil = Image.fromarray(final_sketch)
			col1, col2 = st.columns(2)
            
			with col1: 
				st.header("Original Image") 
				st.image(load_an_image(image_file), width=250) 

			with col2: 
				st.header("Pencil Sketch") 
				st.image(im_pil, width=250) 
				buf = BytesIO() 
				img = im_pil 
				img.save(buf, format="JPEG") 
				byte_im = buf.getvalue() 
				st.download_button( 
					label="Download image", 
					data=byte_im, 
					file_name="watercolorsketch.png", 
					mime="image/png"
				)

if __name__ == '__main__': 
	main()