python类THRESH_BINARY的实例源码

def find_squares(img):
    img = cv2.GaussianBlur(img, (5, 5), 0)
    squares = []
    for gray in cv2.split(img):
        for thrs in xrange(0, 255, 26):
            if thrs == 0:
                bin = cv2.Canny(gray, 0, 50, apertureSize=5)
                bin = cv2.dilate(bin, None)
            else:
                retval, bin = cv2.threshold(gray, thrs, 255, cv2.THRESH_BINARY)
            bin, contours, hierarchy = cv2.findContours(bin, cv2.RETR_LIST, cv2.CHAIN_APPROX_SIMPLE)
            for cnt in contours:
                cnt_len = cv2.arcLength(cnt, True)
                cnt = cv2.approxPolyDP(cnt, 0.02 * cnt_len, True)
                if len(cnt) == 4 and cv2.contourArea(cnt) > 1000 and cv2.isContourConvex(cnt):
                    cnt = cnt.reshape(-1, 2)
                    max_cos = np.max([angle_cos(cnt[i], cnt[(i + 1) % 4], cnt[(i + 2) % 4]) for i in xrange(4)])
                    if max_cos < 0.1:
                        squares.append(cnt)
    return squares

def img_fill(im_in, n):  # n = binary image threshold
    th, im_th = cv2.threshold(im_in, n, 255, cv2.THRESH_BINARY);

    # Copy the thresholded image.
    im_floodfill = im_th.copy()

    # Mask used to flood filling.
    # Notice the size needs to be 2 pixels than the image.
    h, w = im_th.shape[:2]
    mask = np.zeros((h + 2, w + 2), np.uint8)

    # Floodfill from point (0, 0)
    cv2.floodFill(im_floodfill, mask, (0, 0), 255);

    # Invert floodfilled image
    im_floodfill_inv = cv2.bitwise_not(im_floodfill)

    # Combine the two images to get the foreground.
    fill_image = im_th | im_floodfill_inv

    return fill_image

def find_squares(img):
    img = cv2.GaussianBlur(img, (5, 5), 0)
    squares = []
    for gray in cv2.split(img):
        for thrs in xrange(0, 255, 26):
            if thrs == 0:
                bin = cv2.Canny(gray, 0, 50, apertureSize=5)
                bin = cv2.dilate(bin, None)
            else:
                _retval, bin = cv2.threshold(gray, thrs, 255, cv2.THRESH_BINARY)
            contours, _hierarchy = find_contours(bin, cv2.RETR_LIST, cv2.CHAIN_APPROX_SIMPLE)
            for cnt in contours:
                x, y, w, h = cv2.boundingRect(cnt)
                cnt_len = cv2.arcLength(cnt, True)
                cnt = cv2.approxPolyDP(cnt, 0.02*cnt_len, True)
                area = cv2.contourArea(cnt)
                if len(cnt) == 4 and 20 < area < 1000 and cv2.isContourConvex(cnt):
                    cnt = cnt.reshape(-1, 2)
                    max_cos = np.max([angle_cos( cnt[i], cnt[(i+1) % 4], cnt[(i+2) % 4] ) for i in xrange(4)])
                    if max_cos < 0.1:
                        if (1 - (float(w) / float(h)) <= 0.07 and 1 - (float(h) / float(w)) <= 0.07):
                            squares.append(cnt)
    return squares

def threshold_and_label_blobs(intensity, blob_list, threshold):
  # we cheat a little here because we take the list of
  # known blob locations to fill the thresholded areas
  # surrounding the blob centers. This way false blob detections
  # are avoided.
  assert(intensity.dtype == np.uint8)
  W, H = intensity.shape
  _, blobs_mask = cv2.threshold(intensity, threshold, 1, cv2.THRESH_BINARY)
  labels = 255 - blobs_mask
  for num, pk in enumerate(blob_list):
    iy, ix = int(pk.y), int(pk.x)
    if labels[ix, iy] < 254: # was the area under the blob location already filled by another blob?
        return None # overlapping non-separable blobs
    if labels[ix, iy] == 255:
        return None # blob center is not in thresholded area
    cv2.floodFill(labels.reshape((W, H, 1)), None, (iy, ix), (num,), (0,), (0,))
  labels[labels == 254] = 255 # everything not a proper blob is assigned label 255
  return labels

def execute_Threshold(proxy,obj):

    try: img=obj.sourceObject.Proxy.img.copy()
    except: img=cv2.imread(__dir__+'/icons/freek.png')

    # img = cv2.imread('dave.jpg',0) ??
    img = cv2.medianBlur(img,5)
    img = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)


    if obj.globalThresholding:
        ret,th1 = cv2.threshold(img,obj.param1,obj.param2,cv2.THRESH_BINARY)
        obj.Proxy.img = cv2.cvtColor(th1, cv2.COLOR_GRAY2RGB)

    if obj.adaptiveMeanTresholding:
        th2 = cv2.adaptiveThreshold(img,255,cv2.ADAPTIVE_THRESH_MEAN_C,\
                cv2.THRESH_BINARY,11,2)
        obj.Proxy.img = cv2.cvtColor(th2, cv2.COLOR_GRAY2RGB)

    if obj.adaptiveGaussianThresholding:
        th3 = cv2.adaptiveThreshold(img,255,cv2.ADAPTIVE_THRESH_GAUSSIAN_C,\
            cv2.THRESH_BINARY,17,2)
        obj.Proxy.img = cv2.cvtColor(th3, cv2.COLOR_GRAY2RGB)

def find_squares(img, cos_limit = 0.1):
    print('search for squares with threshold %f' % cos_limit)
    img = cv2.GaussianBlur(img, (5, 5), 0)
    squares = []
    for gray in cv2.split(img):
        for thrs in xrange(0, 255, 26):
            if thrs == 0:
                bin = cv2.Canny(gray, 0, 50, apertureSize=5)
                bin = cv2.dilate(bin, None)
            else:
                retval, bin = cv2.threshold(gray, thrs, 255, cv2.THRESH_BINARY)
            bin, contours, hierarchy = cv2.findContours(bin, cv2.RETR_LIST, cv2.CHAIN_APPROX_SIMPLE)
            for cnt in contours:
                cnt_len = cv2.arcLength(cnt, True)
                cnt = cv2.approxPolyDP(cnt, 0.02*cnt_len, True)
                if len(cnt) == 4 and cv2.contourArea(cnt) > 1000 and cv2.isContourConvex(cnt):
                    cnt = cnt.reshape(-1, 2)
                    max_cos = np.max([angle_cos( cnt[i], cnt[(i+1) % 4], cnt[(i+2) % 4] ) for i in xrange(4)])
                    if max_cos < cos_limit :
                        squares.append(cnt)
                    else:
                        #print('dropped a square with max_cos %f' % max_cos)
                        pass
    return squares

###
### Version V2.  Collect meta-data along the way,  with commentary added.
###

def find_bibs(image):
  gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY);
  binary = cv2.GaussianBlur(gray,(5,5),0)
  ret,binary = cv2.threshold(binary, 0, 255, cv2.THRESH_BINARY + cv2.THRESH_OTSU);
  #binary = cv2.adaptiveThreshold(binary, 255, cv2.ADAPTIVE_THRESH_GAUSSIAN_C, cv2.THRESH_BINARY, 11, 2)
  #ret,binary = cv2.threshold(binary, 190, 255, cv2.THRESH_BINARY);

  #lapl = cv2.Laplacian(image,cv2.CV_64F)
  #gray = cv2.cvtColor(lapl, cv2.COLOR_BGR2GRAY);
  #blurred = cv2.GaussianBlur(lapl,(5,5),0)
  #ret,binary = cv2.threshold(blurred, 0, 255, cv2.THRESH_BINARY + cv2.THRESH_OTSU);
  #cv2.imwrite("lapl.jpg", lapl)

  edges = cv2.Canny(image,175,200)
  cv2.imwrite("edges.jpg", edges)
  binary = edges

  cv2.imwrite("binary.jpg", binary)
  contours,hierarchy = find_contours(binary)

  return get_rectangles(contours)

def diff_rect(img1, img2, pos=None):
    """find counters include pos in differences between img1 & img2 (cv2 images)"""
    diff = cv2.absdiff(img1, img2)
    diff = cv2.GaussianBlur(diff, (3, 3), 0)
    edges = cv2.Canny(diff, 100, 200)
    _, thresh = cv2.threshold(edges, 0, 255, cv2.THRESH_BINARY)
    contours, _ = cv2.findContours(thresh, cv2.RETR_TREE, cv2.CHAIN_APPROX_NONE)
    if not contours:
        return None
    contours.sort(key=lambda c: len(c))
    # no pos provide, just return the largest different area rect
    if pos is None:
        cnt = contours[-1]
        x0, y0, w, h = cv2.boundingRect(cnt)
        x1, y1 = x0+w, y0+h
        return (x0, y0, x1, y1)
    # else the rect should contain the pos
    x, y = pos
    for i in range(len(contours)):
        cnt = contours[-1-i]
        x0, y0, w, h = cv2.boundingRect(cnt)
        x1, y1 = x0+w, y0+h
        if x0 <= x <= x1 and y0 <= y <= y1:
            return (x0, y0, x1, y1)

def calculate_entropy(image):
    entropy = image.copy()
    sum = 0
    i = 0
    j = 0
    while i < entropy.shape[0]:
        j = 0
        while j < entropy.shape[1]:
            sub_image = entropy[i:i+10,j:j+10]
            histogram = cv2.calcHist([sub_image],[0],None,[256],[0,256])
            sum = 0
            for k in range(256):
                if histogram[k] != 0:                   
                    sum = sum + (histogram[k] * math.log(histogram[k]))
                k = k + 1
            entropy[i:i+10,j:j+10] = sum
            j = j+10
        i = i+10
    ret2,th2 = cv2.threshold(entropy,0,255,cv2.THRESH_BINARY+cv2.THRESH_OTSU)
    newfin = cv2.erode(th2, cv2.getStructuringElement(cv2.MORPH_ELLIPSE,(3,3)), iterations=1)
    return newfin

def threshold(im_gray, method):
    '''
    ??????????thresholding???????????
    ??????thresholding????????OpenCV??
    '''
    if method == 'fixed':
        threshed_im = cv2.threshold(im_gray, 128, 255, cv2.THRESH_BINARY)

    elif method == 'mean':
        threshed_im = cv2.adaptiveThreshold(im_gray, 255, cv2.ADAPTIVE_THRESH_MEAN_C, cv2.THRESH_BINARY, 15, -22)

    elif method == 'gaussian':
        threshed_im = cv2.adaptiveThreshold(im_gray, 255, cv2.ADAPTIVE_THRESH_GAUSSIAN_C, cv2.THRESH_BINARY, 5, 7)

    else:
        return None

    return threshed_im

def threshold(im_gray, method):
    '''
    ??????????thresholding???????????
    ??????thresholding????????OpenCV??
    '''
    if method == 'fixed':
        threshed_im = cv2.threshold(im_gray, 128, 255, cv2.THRESH_BINARY)

    elif method == 'mean':
        threshed_im = cv2.adaptiveThreshold(im_gray, 255, cv2.ADAPTIVE_THRESH_MEAN_C, cv2.THRESH_BINARY, 15, -22)

    elif method == 'gaussian':
        threshed_im = cv2.adaptiveThreshold(im_gray, 255, cv2.ADAPTIVE_THRESH_GAUSSIAN_C, cv2.THRESH_BINARY, 5, 7)

    else:
        return None

    return threshed_im

def classify(img):
    cimg = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
    img2 = cv2.medianBlur(cimg, 13)

    ret, thresh1 = cv2.threshold(cimg, 100, 120, cv2.THRESH_BINARY)
    t2 = copy.copy(thresh1)

    x, y = thresh1.shape
    arr = np.zeros((x, y, 3), np.uint8)
    final_contours = []
    image, contours, hierarchy = cv2.findContours(t2, cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)
    #cv2.imshow('image', image)
    #k = cv2.waitKey(0)
    for i in range(len(contours)):
        cnt = contours[i]
        if cv2.contourArea(cnt) > 3000 and cv2.contourArea(cnt) < 25000:
            cv2.drawContours(img, [cnt], -1, [0, 255, 255])
            cv2.fillConvexPoly(arr, cnt, [255, 255, 255])
            final_contours.append(cnt)
    #cv2.imshow('arr', arr)
    #k = cv2.waitKey(0)
    return arr

def img_fill(im_in,n):   # n = binary image threshold
    th, im_th = cv2.threshold(im_in, n, 255, cv2.THRESH_BINARY);

    # Copy the thresholded image.
    im_floodfill = im_th.copy()

    # Mask used to flood filling.
    # Notice the size needs to be 2 pixels than the image.
    h, w = im_th.shape[:2]
    mask = np.zeros((h+2, w+2), np.uint8)

    # Floodfill from point (0, 0)
    cv2.floodFill(im_floodfill, mask, (0,0), 255);

    # Invert floodfilled image
    im_floodfill_inv = cv2.bitwise_not(im_floodfill)

    # Combine the two images to get the foreground.
    fill_image = im_th | im_floodfill_inv

    return fill_image

def CropLowerBoundary(img):
    # img_gray = ToGrayImage(path)
    _,img_bi = cv2.threshold(img,60,255,cv2.THRESH_BINARY)
    threshold_rate = 0.95
    threshold_row = -1
    row,col = img_bi.shape
    for tmp_r in range(row-1,-1,-1):
        tmp_sum = sum(img_bi[tmp_r])
        rate = float(tmp_sum)/255/col
        # print(rate)
        if rate>threshold_rate:
            threshold_row = tmp_r
            break
    img = img[0:threshold_row,:]
    # plt.imshow(img,"gray")
    # plt.show()
    return img

def FindLowerBoundary(path,mode):
    img_gray = ToGrayImage(path)
    _,img_bi = cv2.threshold(img_gray,10,255,cv2.THRESH_BINARY)
    threshold_rate = 0.8
    threshold_row = -1
    row,col = img_bi.shape
    for tmp_r in range(row-1,-1,-1):
        tmp_sum = sum(img_bi[tmp_r])
        rate = float(tmp_sum)/255/col
        if rate>threshold_rate:
            threshold_row = tmp_r
            break
    return threshold_row



# GrayScale Image Convertor
# https://extr3metech.wordpress.com

def FindLowerBoundary(path,mode):
    img_gray = ToGrayImage(path)
    _,img_bi = cv2.threshold(img_gray,10,255,cv2.THRESH_BINARY)
    threshold_rate = 0.8
    threshold_row = -1
    row,col = img_bi.shape
    for tmp_r in range(row-1,-1,-1):
        tmp_sum = sum(img_bi[tmp_r])
        rate = float(tmp_sum)/255/col
        if rate>threshold_rate:
            threshold_row = tmp_r
            break
    return threshold_row



# GrayScale Image Convertor
# https://extr3metech.wordpress.com

def find_contour(self, img_src, Rxmin, Rymin, Rxmax, Rymax):
        cv2.rectangle(img_src, (Rxmax, Rymax), (Rxmin, Rymin), (0, 255, 0), 0)
        crop_res = img_src[Rymin: Rymax, Rxmin:Rxmax]
        grey = cv2.cvtColor(crop_res, cv2.COLOR_BGR2GRAY)

        _, thresh1 = cv2.threshold(grey, 127, 255, cv2.THRESH_BINARY + cv2.THRESH_OTSU)

        cv2.imshow('Thresh', thresh1)
        contours, hierchy = cv2.findContours(thresh1.copy(), cv2.RETR_TREE, cv2.CHAIN_APPROX_NONE)

        # draw contour on threshold image
        if len(contours) > 0:
            cv2.drawContours(thresh1, contours, -1, (0, 255, 0), 3)

        return contours, crop_res


# Check ConvexHull  and Convexity Defects

def detect_edges(images):
        def blur(image):
            return cv2.GaussianBlur(image, (5, 5), 0)

        def canny_otsu(image):
            scale_factor = 255
            scaled_image = np.uint8(image * scale_factor)

            otsu_threshold = cv2.threshold(
                cv2.cvtColor(scaled_image, cv2.COLOR_RGB2GRAY), 0, 255, cv2.THRESH_BINARY + cv2.THRESH_OTSU)[0]
            lower_threshold = max(0, int(otsu_threshold * 0.5))
            upper_threshold = min(255, int(otsu_threshold))
            edges = cv2.Canny(scaled_image, lower_threshold, upper_threshold)
            edges = cv2.cvtColor(edges, cv2.COLOR_GRAY2RGB)

            return np.float32(edges) * (1 / scale_factor)

        blurred = [blur(image) for image in images]
        canny_applied = [canny_otsu(image) for image in blurred]

        return canny_applied

def cannyThresholding(self, contour_retrieval_mode = cv2.RETR_LIST):
        '''
        contour_retrieval_mode is passed through as second argument to cv2.findContours
        '''

        # Attempt to match edges found in blue, green or red channels : collect all
        channel = 0
        for gray in cv2.split(self.img):
            channel += 1
            print('channel %d ' % channel)
            title = self.tgen.next('channel-%d' % channel)
            if self.show: ImageViewer(gray).show(window = title, destroy = self.destroy, info = self.info, thumbnailfn = title)
            found = {}
            for thrs in xrange(0, 255, 26):
                print('Using threshold %d' % thrs)
                if thrs == 0:
                    print('First step')
                    bin = cv2.Canny(gray, 0, 50, apertureSize=5)
                    title = self.tgen.next('canny-%d' % channel)
                    if self.show: ImageViewer(bin).show(window = title, destroy = self.destroy, info = self.info, thumbnailfn = title)
                    bin = cv2.dilate(bin, None)
                    title = self.tgen.next('canny-dilate-%d' % channel)
                    if self.show: ImageViewer(bin).show(window = title, destroy = self.destroy, info = self.info, thumbnailfn = title)
                else:
                    retval, bin = cv2.threshold(gray, thrs, 255, cv2.THRESH_BINARY)
                    title = self.tgen.next('channel-%d-threshold-%d' % (channel, thrs))
                    if self.show: ImageViewer(bin).show(window='Next threshold (n to continue)', destroy = self.destroy, info = self.info, thumbnailfn = title)
                bin, contours, hierarchy = cv2.findContours(bin, contour_retrieval_mode, cv2.CHAIN_APPROX_SIMPLE)
                title = self.tgen.next('channel-%d-threshold-%d-contours' % (channel, thrs))
                if self.show: ImageViewer(bin).show(window = title, destroy = self.destroy, info = self.info, thumbnailfn = title)
                if contour_retrieval_mode == cv2.RETR_LIST or contour_retrieval_mode == cv2.RETR_EXTERNAL:
                    filteredContours = contours
                else:
                    filteredContours = []
                    h = hierarchy[0]
                    for component in zip(contours, h):
                        currentContour = component[0]
                        currentHierarchy = component[1]
                        if currentHierarchy[3] < 0:
                            # Found the outermost parent component
                            filteredContours.append(currentContour)
                    print('Contours filtered.   Input %d  Output %d' % (len(contours), len(filteredContours)))
                    time.sleep(5)
                for cnt in filteredContours:
                    cnt_len = cv2.arcLength(cnt, True)
                    cnt = cv2.approxPolyDP(cnt, 0.02*cnt_len, True)
                    cnt_len = len(cnt)
                    cnt_area = cv2.contourArea(cnt)
                    cnt_isConvex = cv2.isContourConvex(cnt)
                    if cnt_len == 4 and (cnt_area > self.area_min and cnt_area < self.area_max)  and cnt_isConvex:
                        cnt = cnt.reshape(-1, 2)
                        max_cos = np.max([angle_cos( cnt[i], cnt[(i+1) % 4], cnt[(i+2) % 4] ) for i in xrange(4)])
                        if max_cos < self.cos_limit :
                            sq = Square(cnt, cnt_area, cnt_isConvex, max_cos)
                            self.squares.append(sq)
                        else:
                            #print('dropped a square with max_cos %f' % max_cos)
                            pass
                found[thrs] = len(self.squares)
                print('Found %d quadrilaterals with threshold %d' % (len(self.squares), thrs))

def find_bib(image):
  width, height, depth = image.shape

  gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY);
  #gray = cv2.equalizeHist(gray)
  blurred = cv2.GaussianBlur(gray,(5,5),0)

  debug_output("find_bib_blurred", blurred)
  #binary = cv2.adaptiveThreshold(blurred, 255, cv2.ADAPTIVE_THRESH_GAUSSIAN_C, cv2.THRESH_BINARY, blockSize=25, C=0);
  ret,binary = cv2.threshold(blurred, 0, 255, cv2.THRESH_BINARY + cv2.THRESH_OTSU);
  #ret,binary = cv2.threshold(blurred, 170, 255, cv2.THRESH_BINARY);
  debug_output("find_bib_binary", binary)
  threshold_contours,hierarchy = find_contours(binary)

  debug_output("find_bib_threshold", binary)

  edges = cv2.Canny(gray,175,200, 3)
  edge_contours,hierarchy = find_contours(edges)

  debug_output("find_bib_edges", edges)

  contours = threshold_contours + edge_contours
  debug_output_contours("find_bib_threshold_contours", image, contours)

  rectangles = get_rectangles(contours)

  debug_output_contours("find_bib_rectangles", image, rectangles)

  potential_bibs = [rect for rect in rectangles if is_potential_bib(rect, width*height)]

  debug_output_contours("find_bib_potential_bibs", image, potential_bibs)

  ideal_aspect_ratio = 1.0
  potential_bibs = sorted(potential_bibs, key = lambda bib: abs(aspect_ratio(bib) - ideal_aspect_ratio))

  return potential_bibs[0] if len(potential_bibs) > 0 else np.array([[(0,0)],[(0,0)],[(0,0)],[(0,0)]])

#
# Checks that the size and aspect ratio of the contour is appropriate for a bib.
#

def diff_rect(img1, img2, pos=None):
    """find counters include pos in differences between img1 & img2 (cv2 images)"""
    diff = cv2.absdiff(img1, img2)
    diff = cv2.GaussianBlur(diff, (3, 3), 0)
    edges = cv2.Canny(diff, 100, 200)
    _, thresh = cv2.threshold(edges, 0, 255, cv2.THRESH_BINARY)
    contours, _ = cv2.findContours(thresh, cv2.RETR_TREE, cv2.CHAIN_APPROX_NONE)
    if not contours:
        return None
    contours.sort(key=lambda c: len(c))
    # no pos provide, just return the largest different area rect
    if pos is None:
        cnt = contours[-1]
        x0, y0, w, h = cv2.boundingRect(cnt)
        x1, y1 = x0+w, y0+h
        return (x0, y0, x1, y1)
    # else the rect should contain the pos
    x, y = pos
    for i in range(len(contours)):
        cnt = contours[-1-i]
        x0, y0, w, h = cv2.boundingRect(cnt)
        x1, y1 = x0+w, y0+h
        if x0 <= x <= x1 and y0 <= y <= y1:
            return (x0, y0, x1, y1)

def find_chars(img):
    gray = np.array(img.convert("L"))
    ret, mask = cv2.threshold(gray, 180, 255, cv2.THRESH_BINARY)
    image_final = cv2.bitwise_and(gray, gray, mask=mask)
    ret, new_img = cv2.threshold(image_final, 180, 255, cv2.THRESH_BINARY_INV)
    kernel = cv2.getStructuringElement(cv2.MORPH_CROSS, (3, 3))
    dilated = cv2.dilate(new_img, kernel, iterations=1)
    # Image.fromarray(dilated).save('out.png') # for debugging
    _, contours, hierarchy = cv2.findContours(dilated, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_NONE)

    coords = []
    for contour in contours:
        # get rectangle bounding contour
        [x, y, w, h] = cv2.boundingRect(contour)
        # ignore large chars (probably not chars)
        if w > 70 and h > 70:
            continue
        coords.append((x, y, w, h))
    return coords


# find list of eye coordinates in image

def cropCircle(img, resize=None):
    if resize:
        if (img.shape[0] > img.shape[1]):
            tile_size = (int(img.shape[1] * resize / img.shape[0]), resize)
        else:
            tile_size = (resize, int(img.shape[0] * resize / img.shape[1]))
        img = cv2.resize(img, dsize=tile_size, interpolation=cv2.INTER_CUBIC)
    else:
        tile_size = img.shape

    gray = cv2.cvtColor(img, cv2.COLOR_RGB2GRAY);
    _, thresh = cv2.threshold(gray, 10, 255, cv2.THRESH_BINARY)

    _, contours, _ = cv2.findContours(thresh.copy(), cv2.RETR_TREE, cv2.CHAIN_APPROX_NONE)

    main_contour = sorted(contours, key=cv2.contourArea, reverse=True)[0]

    ff = np.zeros((gray.shape[0], gray.shape[1]), 'uint8')
    cv2.drawContours(ff, main_contour, -1, 1, 15)
    ff_mask = np.zeros((gray.shape[0] + 2, gray.shape[1] + 2), 'uint8')
    cv2.floodFill(ff, ff_mask, (int(gray.shape[1] / 2), int(gray.shape[0] / 2)), 1)

    rect = maxRect(ff)
    rectangle = [min(rect[0], rect[2]), max(rect[0], rect[2]), min(rect[1], rect[3]), max(rect[1], rect[3])]
    img_crop = img[rectangle[0]:rectangle[1], rectangle[2]:rectangle[3]]
    cv2.rectangle(ff, (min(rect[1], rect[3]), min(rect[0], rect[2])), (max(rect[1], rect[3]), max(rect[0], rect[2])), 3,
                  2)

    return [img_crop, rectangle, tile_size]

def load(self, filename, analyze_only):
    # Load image, then do various conversions and thresholding.
    self.img_orig = cv2.imread(filename, cv2.IMREAD_COLOR)

    if self.img_orig is None:
      raise CompilerException("File '{}' not found".format(filename))

    self.img_grey = cv2.cvtColor(self.img_orig, cv2.COLOR_BGR2GRAY)
    _, self.img_contour = cv2.threshold(self.img_grey, 250, 255, cv2.THRESH_BINARY_INV)
    _, self.img_text = cv2.threshold(self.img_grey, 150, 255, cv2.THRESH_BINARY)
    self.root_node = None

    self.contours = self.find_contours()

    self.contour_lines, self.contour_nodes = self.categorize_contours()

    self.build_graph()
    self.build_parse_tree()

    self.parse_nodes()

    if not analyze_only:
      self.python_ast = self.root_node.to_python_ast()

def overlay_img(self):
        """Overlay the transparent, transformed image of the arc onto our CV image"""
        #overlay the arc on the image
        rows, cols, channels = self.transformed.shape
        roi = self.cv_image[0:rows, 0:cols]

        #change arc_image to grayscale
        arc2gray = cv2.cvtColor(self.transformed, cv2.COLOR_BGR2GRAY)
        ret, mask = cv2.threshold(arc2gray, 10, 255, cv2.THRESH_BINARY)
        mask_inv = cv2.bitwise_not(mask)

        #black out area of arc in ROI
        img1_bg = cv2.bitwise_and(roi, roi, mask=mask_inv)
        img2_fg = cv2.bitwise_and(self.transformed, self.transformed, mask=mask)

        #put arc on ROI and modify the main image
        dst = cv2.add(img1_bg, img2_fg)
        self.cv_image[0:rows, 0:cols] = dst

def extract_color( src, h_th_low, h_th_up, s_th, v_th ):
    hsv = cv2.cvtColor(src, cv2.COLOR_BGR2HSV)
    h, s, v = cv2.split(hsv)
    if h_th_low > h_th_up:
        ret, h_dst_1 = cv2.threshold(h, h_th_low, 255, cv2.THRESH_BINARY) 
        ret, h_dst_2 = cv2.threshold(h, h_th_up,  255, cv2.THRESH_BINARY_INV)

        dst = cv2.bitwise_or(h_dst_1, h_dst_2)
    else:
        ret, dst = cv2.threshold(h,   h_th_low, 255, cv2.THRESH_TOZERO) 
        ret, dst = cv2.threshold(dst, h_th_up,  255, cv2.THRESH_TOZERO_INV)
        ret, dst = cv2.threshold(dst, 0, 255, cv2.THRESH_BINARY)

    ret, s_dst = cv2.threshold(s, s_th, 255, cv2.THRESH_BINARY)
    ret, v_dst = cv2.threshold(v, v_th, 255, cv2.THRESH_BINARY)
    dst = cv2.bitwise_and(dst, s_dst)
    dst = cv2.bitwise_and(dst, v_dst)
    return dst

def calculate_entropy(image):
    entropy = image.copy()
    sum = 0
    i = 0
    j = 0
    while i < entropy.shape[0]:
        j = 0
        while j < entropy.shape[1]:
            sub_image = entropy[i:i+10,j:j+10]
            histogram = cv2.calcHist([sub_image],[0],None,[256],[0,256])
            sum = 0
            for k in range(256):
                if histogram[k] != 0:                   
                    sum = sum + (histogram[k] * math.log(histogram[k]))
                k = k + 1
            entropy[i:i+10,j:j+10] = sum
            j = j+10
        i = i+10
    ret2,th2 = cv2.threshold(entropy,0,255,cv2.THRESH_BINARY+cv2.THRESH_OTSU)
    newfin = cv2.erode(th2, cv2.getStructuringElement(cv2.MORPH_ELLIPSE,(3,3)), iterations=1)
    return newfin

def recognize_text(original):
    idcard = original
    gray = cv2.cvtColor(idcard, cv2.COLOR_BGR2GRAY)

    # Morphological gradient:
    kernel = cv2.getStructuringElement(cv2.MORPH_ELLIPSE, (5, 5))
    opening = cv2.morphologyEx(gray, cv2.MORPH_GRADIENT, kernel)

    # Binarization
    ret, binarization = cv2.threshold(opening, 0.0, 255.0, cv2.THRESH_BINARY | cv2.THRESH_OTSU)

    # Connected horizontally oriented regions
    kernel = cv2.getStructuringElement(cv2.MORPH_RECT, (9, 1))
    connected = cv2.morphologyEx(binarization, cv2.MORPH_CLOSE, kernel)

    # find countours
    _, contours, hierarchy = cv2.findContours(
        connected, cv2.RETR_CCOMP, cv2.CHAIN_APPROX_SIMPLE
    )
    return contours, hierarchy

def _extract_arm(self, img):
        # find center region of image frame (assume center region is 21 x 21 px)
        center_half = 10 # (=(21-1)/2)  
        center = img[self.height/2 - center_half : self.height/2 + center_half, self.width/2 - center_half : self.width/2 + center_half]

        # determine median depth value
        median_val = np.median(center)

        '''mask the image such that all pixels whose depth values
        lie within a particular range are gray and the rest are black
        '''

        img = np.where(abs(img-median_val) <= self.abs_depth_dev, 128, 0).astype(np.uint8)

        # Apply morphology operation to fill small holes in the image
        kernel = np.ones((5,5), np.uint8)
        img = cv2.morphologyEx(img, cv2.MORPH_CLOSE, kernel)

        # Find connected regions (to hand) to remove background objects
        # Use floodfill with a small image area (7 x 7 px) that is set gray color value
        kernel2 = 3
        img[self.height/2-kernel2:self.height/2+kernel2, self.width/2-kernel2:self.width/2+kernel2] = 128

        # a black mask to mask the 'non-connected' components black
        mask = np.zeros((self.height + 2, self.width + 2), np.uint8)
        floodImg = img.copy()

        # Use floodFill function to paint the connected regions white 
        cv2.floodFill(floodImg, mask, (self.width/2, self.height/2), 255, flags=(4 | 255 << 8))

        # apply a binary threshold to show only connected hand region
        ret, floodedImg = cv2.threshold(floodImg, 129, 255, cv2.THRESH_BINARY)

        return floodedImg

def thresholding(img_grey):
    """
    This functions creates binary images using thresholding
    :param img_grey: greyscale image
    :return: binary image
    """
    # # Adaptive Gaussian
    # img_binary = cv.adaptiveThreshold(img_grey, 255, cv.ADAPTIVE_THRESH_GAUSSIAN_C, cv.THRESH_BINARY, 11, 2)

    # Otsu's thresholding after Gaussian filtering
    blur = cv.GaussianBlur(img_grey, (5, 5), 0)
    ret3, img_binary = cv.threshold(blur, 0, 255, cv.THRESH_BINARY + cv.THRESH_OTSU)

    # invert black = 255
    ret, thresh1 = cv.threshold(img_binary, 127, 255, cv.THRESH_BINARY_INV)

    return thresh1