app.py

import gradio as gr
import cv2
import os

title = "Convert image to sketch"
description = "This app uses OpenCV to convert an image to a pencil sketch. Simply upload an image, and the app will return a sketched version of the image."
ref = "Find the whole code [here](https://github.com/jazlopez/py-sketch-image/)."

def sketch(image, sigma_s, sigma_r, shade):
  SIGMA_S= sigma_s
  SIGMA_R= sigma_r
  SHADE_FACTOR= shade
  imageSizeX=image.shape[0]
  imageSizeY=image.shape[1]
  print('Processing image with size: x', imageSizeX, ', y', imageSizeY, '...')

  imageToSketch = image

  if imageSizeX > 3000 or imageSizeY > 3000:
    print('Image too big, resizing to 1/6...')
    imageToSketch = cv2.resize(imageToSketch, (int(imageSizeY/6), int(imageSizeX/6)), interpolation=cv2.INTER_AREA)
  elif imageSizeX > 2000 or imageSizeY > 2000:
    print('Image too big, resizing to 1/4...')
    imageToSketch = cv2.resize(imageToSketch, (int(imageSizeY/4), int(imageSizeX/4)), interpolation=cv2.INTER_AREA)
  elif imageSizeX > 1500 or imageSizeY > 1500:
    print('Image too big, resizing to 1/3...')
    imageToSketch = cv2.resize(imageToSketch, (int(imageSizeY/3), int(imageSizeX/3)), interpolation=cv2.INTER_AREA)
  elif imageSizeX > 1000 or imageSizeY > 1000:
    print('Image too big, resizing to 1/2...')
    imageToSketch = cv2.resize(imageToSketch, (int(imageSizeY/2), int(imageSizeX/2)), interpolation=cv2.INTER_AREA)

  try:
    sk_gray, sk_color=cv2.pencilSketch(imageToSketch, sigma_s=SIGMA_S, sigma_r=SIGMA_R, shade_factor=SHADE_FACTOR)
    print('Image processed successfully!')
    return sk_gray
  except:
    print('Error processing image...')
    return image

demo = gr.Interface(
  fn=sketch, 
  inputs=[
    gr.Image(), 
    gr.Slider(0, 100, step=1, value=50), 
    gr.Slider(0, 0.1, step=0.01, value=0.05), 
    gr.Slider(0, 0.1, step=0.01, value=0.05)
    ], 
    outputs=[gr.Image(height=500)], 
    title=title, 
    description=description,
    article=ref,
    examples=[
      [os.path.join(os.path.dirname(__file__), "images/source.jpg")]
      ],
    allow_flagging='never',
  )
    
demo.queue().launch()