test3.py

import os
import cv2
import numpy as np
import matplotlib.pyplot as plt

def detect_box(image,line_min_width = 15):
    gray_scale=cv2.cvtColor(image,cv2.COLOR_BGR2GRAY)
    th1,img_bin = cv2.threshold(gray_scale,150,225,cv2.THRESH_BINARY)
    kernal6h = np.ones((1,line_min_width), np.uint8)
    kernal6v = np.ones((line_min_width,1), np.uint8)
    img_bin_h = cv2.morphologyEx(~img_bin, cv2.MORPH_OPEN, kernal6h)
    img_bin_v = cv2.morphologyEx(~img_bin, cv2.MORPH_OPEN, kernal6v)
    img_bin_final=img_bin_h|img_bin_v
    final_kernel = np.ones((3, 3), np.uint8)
    img_bin_final=cv2.dilate(img_bin_final,final_kernel,iterations=1)
    _, labels, stats,_ = cv2.connectedComponentsWithStats(~img_bin_final, connectivity=8, ltype=cv2.CV_32S)
    return stats,labels

def plot(image,cmap=None):
    plt.figure(figsize=(15, 15))
    plt.imshow(image,cmap=cmap)
    plt.show()

def imshow_components(labels):
    ### creating a hsv image, with a unique hue value for each label
    label_hue = np.uint8(179*labels/np.max(labels))
    ### making saturation and volume to be 255
    empty_channel = 255*np.ones_like(label_hue)
    labeled_img = cv2.merge([label_hue, empty_channel, empty_channel])
    ### converting the hsv image to BGR image
    labeled_img = cv2.cvtColor(labeled_img, cv2.COLOR_HSV2BGR)
    labeled_img[label_hue==0] = 0
    ### returning the color image for visualising Connected Componenets
    return labeled_img

def check_ticked(image, checkbox, threshold = 127):
    x,y,w,h = checkbox
    low = 0
    high = 0
    for i in range(w):
        for j in range(h):
            if image[y + j][x + i] < threshold:
                low += 1
            else:
                high += 1
    if low * 100 / (low + high) > 5:
        return True
    return False

def pos_to_index(form, pos):
    posx = 0
    posy = 0
    while pos > 0:
        pos -= 1
        len_aux = len(form[posx])
        if posy >= len_aux - 1:
            posy = 0
            posx += 1
        else:
            posy += 1
    return posx, posy

def get_checkboxes(image, stats):
    result = []
    height, width, _ = image.shape
    for x,y,w,h,_ in stats[2:]:
        relative_w = w * 100 / width
        relative_h = h * 100 / height
        if relative_w < 0.8 and relative_h < 0.6 and relative_w > 0.5 and relative_h > 0.4:
        #if True:
            cv2.rectangle(image, (x - 1, y - 1), (x + w + 1, y + h + 1), (0, 255, 0), 1)
            result.append([x - 1, y - 1, w + 1, h + 1])
            print(relative_w, relative_h)
    return result

def get_form_shape(checkboxes, threshold = 10):
    rows = []
    last_y = -11
    i = -1
    for box in checkboxes:
        if abs (box[1] - last_y) > threshold:
            i += 1
            last_y = box[1]
            rows.append([0])
        else:
            rows[i].append(0)
    return rows

def check_ticked(image, checkbox, threshold = 127):
    x,y,w,h = checkbox
    low = 0
    high = 0
    for i in range(w):
        for j in range(h):
            if image[y + j][x + i] < threshold:
                low += 1
            else:
                high += 1
    if low * 100 / (low + high) > 5:
        return True
    return False

def pos_to_index(form, pos):
    posx = 0
    posy = 0
    while pos > 0:
        pos -= 1
        len_aux = len(form[posx])
        if posy >= len_aux - 1:
            posy = 0
            posx += 1
        else:
            posy += 1
    return posx, posy

def pretty_print(form):
    for iterator, mini_list in enumerate(form):
        print("Question " + str(iterator + 1) + ":")
        for option, element in enumerate(mini_list):
            print("option " + chr(option + 65) + ": " + str(element))
        print("\n")


def main():
    image_path='second.jpg'
    image=cv2.imread(image_path)
    height, width, channels = image.shape
    stats,labels = detect_box(image, line_min_width = 1)

    plot_flag=False
    save_output=True
    out_folder='outs'
    os.makedirs(out_folder,exist_ok=True)

    checkboxes = get_checkboxes(image, stats)
    form = get_form_shape(checkboxes)
    image_path2 = 'checkedsecond.png'
    image2=cv2.imread(image_path2)
    gray = cv2.cvtColor(image2, cv2.COLOR_BGR2GRAY)

    counter = 0
    for box in checkboxes:
        check = check_ticked(gray, box)
        if check == True:
            posx, posy = pos_to_index(form, counter)
            form[posx][posy] += 1
        counter += 1
    
    pretty_print(form)
    if plot_flag:
        #plot(cc_out)
        plot(image)
    if save_output:
        #cv2.imwrite(os.path.join(out_folder,f'cc_{image_path}'),cc_out)
        cv2.imwrite(os.path.join(out_folder,f'out_{image_path}'),image)


if __name__ == "__main__":
    main()