#!/usr/bin/env python3
# -*- coding: utf-8 -*-
import tempfile
import cv2
import logging
import numpy as np
from PIL import Image
IMAGE_SIZE = 1800
BINARY_THREHOLD = 180
size = None
def get_size_of_scaled_image(im):
global size
if size is None:
length_x, width_y = im.size
factor = max(1, int(IMAGE_SIZE / length_x))
size = factor * length_x, factor * width_y
return size
def process_image_for_ocr(file_path):
logging.info('Processing image for text Extraction')
temp_filename = set_image_dpi(file_path)
im_new = remove_noise_and_smooth(temp_filename)
return im_new
def set_image_dpi(file_path):
im = Image.open(file_path)
# size = (1800, 1800)
size = get_size_of_scaled_image(im)
im_resized = im.resize(size, Image.ANTIALIAS)
temp_file = tempfile.NamedTemporaryFile(delete=False, suffix='.jpg')
temp_filename = temp_file.name
im_resized.save(temp_filename, dpi=(300, 300)) # best for OCR
return temp_filename
def image_smoothening(img):
ret1, th1 = cv2.threshold(img, BINARY_THREHOLD, 255, cv2.THRESH_BINARY)
ret2, th2 = cv2.threshold(th1, 0, 255, cv2.THRESH_BINARY + cv2.THRESH_OTSU)
blur = cv2.GaussianBlur(th2, (1, 1), 0)
ret3, th3 = cv2.threshold(blur, 0, 255, cv2.THRESH_BINARY + cv2.THRESH_OTSU)
return th3
def remove_noise_and_smooth(file_name):
logging.info('Removing noise and smoothening image')
img = cv2.imread(file_name, 0)
filtered = cv2.adaptiveThreshold(img.astype(np.uint8), 255, cv2.ADAPTIVE_THRESH_MEAN_C, cv2.THRESH_BINARY, 41, 3)
kernel = np.ones((1, 1), np.uint8)
opening = cv2.morphologyEx(filtered, cv2.MORPH_OPEN, kernel)
closing = cv2.morphologyEx(opening, cv2.MORPH_CLOSE, kernel)
img = image_smoothening(img)
or_image = cv2.bitwise_or(img, closing)
return or_image
