eynollah/src/eynollah/utils/utils_ocr.py

488 lines
19 KiB
Python

import numpy as np
import cv2
import tensorflow as tf
from scipy.signal import find_peaks
from scipy.ndimage import gaussian_filter1d
import math
from PIL import Image, ImageDraw, ImageFont
from Bio import pairwise2
from .resize import resize_image
def decode_batch_predictions(pred, num_to_char, max_len = 128):
# input_len is the product of the batch size and the
# number of time steps.
input_len = np.ones(pred.shape[0]) * pred.shape[1]
# Decode CTC predictions using greedy search.
# decoded is a tuple with 2 elements.
decoded = tf.keras.backend.ctc_decode(pred,
input_length = input_len,
beam_width = 100)
# The outputs are in the first element of the tuple.
# Additionally, the first element is actually a list,
# therefore we take the first element of that list as well.
#print(decoded,'decoded')
decoded = decoded[0][0][:, :max_len]
#print(decoded, decoded.shape,'decoded')
output = []
for d in decoded:
# Convert the predicted indices to the corresponding chars.
d = tf.strings.reduce_join(num_to_char(d))
d = d.numpy().decode("utf-8")
output.append(d)
return output
def distortion_free_resize(image, img_size):
w, h = img_size
image = tf.image.resize(image, size=(h, w), preserve_aspect_ratio=True)
# Check tha amount of padding needed to be done.
pad_height = h - tf.shape(image)[0]
pad_width = w - tf.shape(image)[1]
# Only necessary if you want to do same amount of padding on both sides.
if pad_height % 2 != 0:
height = pad_height // 2
pad_height_top = height + 1
pad_height_bottom = height
else:
pad_height_top = pad_height_bottom = pad_height // 2
if pad_width % 2 != 0:
width = pad_width // 2
pad_width_left = width + 1
pad_width_right = width
else:
pad_width_left = pad_width_right = pad_width // 2
image = tf.pad(
image,
paddings=[
[pad_height_top, pad_height_bottom],
[pad_width_left, pad_width_right],
[0, 0],
],
)
image = tf.transpose(image, (1, 0, 2))
image = tf.image.flip_left_right(image)
return image
def return_start_and_end_of_common_text_of_textline_ocr_without_common_section(textline_image):
width = np.shape(textline_image)[1]
height = np.shape(textline_image)[0]
common_window = int(0.06*width)
width1 = int ( width/2. - common_window )
width2 = int ( width/2. + common_window )
img_sum = np.sum(textline_image[:,:,0], axis=0)
sum_smoothed = gaussian_filter1d(img_sum, 3)
peaks_real, _ = find_peaks(sum_smoothed, height=0)
if len(peaks_real)>70:
peaks_real = peaks_real[(peaks_real<width2) & (peaks_real>width1)]
arg_max = np.argmax(sum_smoothed[peaks_real])
peaks_final = peaks_real[arg_max]
return peaks_final
else:
return None
# Function to fit text inside the given area
def fit_text_single_line(draw, text, font_path, max_width, max_height):
initial_font_size = 50
font_size = initial_font_size
while font_size > 10: # Minimum font size
font = ImageFont.truetype(font_path, font_size)
text_bbox = draw.textbbox((0, 0), text, font=font) # Get text bounding box
text_width = text_bbox[2] - text_bbox[0]
text_height = text_bbox[3] - text_bbox[1]
if text_width <= max_width and text_height <= max_height:
return font # Return the best-fitting font
font_size -= 2 # Reduce font size and retry
return ImageFont.truetype(font_path, 10) # Smallest font fallback
def return_textlines_split_if_needed(textline_image, textline_image_bin, prediction_with_both_of_rgb_and_bin=False):
split_point = return_start_and_end_of_common_text_of_textline_ocr_without_common_section(textline_image)
if split_point:
image1 = textline_image[:, :split_point,:]# image.crop((0, 0, width2, height))
image2 = textline_image[:, split_point:,:]#image.crop((width1, 0, width, height))
if prediction_with_both_of_rgb_and_bin:
image1_bin = textline_image_bin[:, :split_point,:]# image.crop((0, 0, width2, height))
image2_bin = textline_image_bin[:, split_point:,:]#image.crop((width1, 0, width, height))
return [image1, image2], [image1_bin, image2_bin]
else:
return [image1, image2], None
else:
return None, None
def preprocess_and_resize_image_for_ocrcnn_model(img, image_height, image_width):
if img.shape[0]==0 or img.shape[1]==0:
img_fin = np.ones((image_height, image_width, 3))
else:
ratio = image_height /float(img.shape[0])
w_ratio = int(ratio * img.shape[1])
if w_ratio <= image_width:
width_new = w_ratio
else:
width_new = image_width
if width_new == 0:
width_new = img.shape[1]
img = resize_image(img, image_height, width_new)
img_fin = np.ones((image_height, image_width, 3))*255
img_fin[:,:width_new,:] = img[:,:,:]
img_fin = img_fin / 255.
return img_fin
def get_deskewed_contour_and_bb_and_image(contour, image, deskew_angle):
(h_in, w_in) = image.shape[:2]
center = (w_in // 2, h_in // 2)
rotation_matrix = cv2.getRotationMatrix2D(center, deskew_angle, 1.0)
cos_angle = abs(rotation_matrix[0, 0])
sin_angle = abs(rotation_matrix[0, 1])
new_w = int((h_in * sin_angle) + (w_in * cos_angle))
new_h = int((h_in * cos_angle) + (w_in * sin_angle))
rotation_matrix[0, 2] += (new_w / 2) - center[0]
rotation_matrix[1, 2] += (new_h / 2) - center[1]
deskewed_image = cv2.warpAffine(image, rotation_matrix, (new_w, new_h))
contour_points = np.array(contour, dtype=np.float32)
transformed_points = cv2.transform(np.array([contour_points]), rotation_matrix)[0]
x, y, w, h = cv2.boundingRect(np.array(transformed_points, dtype=np.int32))
cropped_textline = deskewed_image[y:y+h, x:x+w]
return cropped_textline
def rotate_image_with_padding(image, angle, border_value=(0,0,0)):
# Get image dimensions
(h, w) = image.shape[:2]
# Calculate the center of the image
center = (w // 2, h // 2)
# Get the rotation matrix
rotation_matrix = cv2.getRotationMatrix2D(center, angle, 1.0)
# Compute the new bounding dimensions
cos = abs(rotation_matrix[0, 0])
sin = abs(rotation_matrix[0, 1])
new_w = int((h * sin) + (w * cos))
new_h = int((h * cos) + (w * sin))
# Adjust the rotation matrix to account for translation
rotation_matrix[0, 2] += (new_w / 2) - center[0]
rotation_matrix[1, 2] += (new_h / 2) - center[1]
# Perform the rotation
try:
rotated_image = cv2.warpAffine(image, rotation_matrix, (new_w, new_h), borderValue=border_value)
except:
rotated_image = np.copy(image)
return rotated_image
def get_orientation_moments(contour):
moments = cv2.moments(contour)
if moments["mu20"] - moments["mu02"] == 0: # Avoid division by zero
return 90 if moments["mu11"] > 0 else -90
else:
angle = 0.5 * np.arctan2(2 * moments["mu11"], moments["mu20"] - moments["mu02"])
return np.degrees(angle) # Convert radians to degrees
def get_orientation_moments_of_mask(mask):
mask=mask.astype('uint8')
contours, _ = cv2.findContours(mask[:,:,0], cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
largest_contour = max(contours, key=cv2.contourArea) if contours else None
moments = cv2.moments(largest_contour)
if moments["mu20"] - moments["mu02"] == 0: # Avoid division by zero
return 90 if moments["mu11"] > 0 else -90
else:
angle = 0.5 * np.arctan2(2 * moments["mu11"], moments["mu20"] - moments["mu02"])
return np.degrees(angle) # Convert radians to degrees
def get_contours_and_bounding_boxes(mask):
# Find contours in the binary mask
contours, _ = cv2.findContours(mask, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
largest_contour = max(contours, key=cv2.contourArea) if contours else None
# Get the bounding rectangle for the contour
x, y, w, h = cv2.boundingRect(largest_contour)
#bounding_boxes.append((x, y, w, h))
return x, y, w, h
def return_splitting_point_of_image(image_to_spliited):
width = np.shape(image_to_spliited)[1]
height = np.shape(image_to_spliited)[0]
common_window = int(0.03*width)
width1 = int ( common_window)
width2 = int ( width - common_window )
img_sum = np.sum(image_to_spliited[:,:,0], axis=0)
sum_smoothed = gaussian_filter1d(img_sum, 1)
peaks_real, _ = find_peaks(sum_smoothed, height=0)
peaks_real = peaks_real[(peaks_real<width2) & (peaks_real>width1)]
arg_sort = np.argsort(sum_smoothed[peaks_real])
peaks_sort_4 = peaks_real[arg_sort][::-1][:3]
return np.sort(peaks_sort_4)
def break_curved_line_into_small_pieces_and_then_merge(img_curved, mask_curved, img_bin_curved=None):
peaks_4 = return_splitting_point_of_image(img_curved)
if len(peaks_4)>0:
imgs_tot = []
for ind in range(len(peaks_4)+1):
if ind==0:
img = img_curved[:, :peaks_4[ind], :]
if img_bin_curved is not None:
img_bin = img_bin_curved[:, :peaks_4[ind], :]
mask = mask_curved[:, :peaks_4[ind], :]
elif ind==len(peaks_4):
img = img_curved[:, peaks_4[ind-1]:, :]
if img_bin_curved is not None:
img_bin = img_bin_curved[:, peaks_4[ind-1]:, :]
mask = mask_curved[:, peaks_4[ind-1]:, :]
else:
img = img_curved[:, peaks_4[ind-1]:peaks_4[ind], :]
if img_bin_curved is not None:
img_bin = img_bin_curved[:, peaks_4[ind-1]:peaks_4[ind], :]
mask = mask_curved[:, peaks_4[ind-1]:peaks_4[ind], :]
or_ma = get_orientation_moments_of_mask(mask)
if img_bin_curved is not None:
imgs_tot.append([img, mask, or_ma, img_bin] )
else:
imgs_tot.append([img, mask, or_ma] )
w_tot_des_list = []
w_tot_des = 0
imgs_deskewed_list = []
imgs_bin_deskewed_list = []
for ind in range(len(imgs_tot)):
img_in = imgs_tot[ind][0]
mask_in = imgs_tot[ind][1]
ori_in = imgs_tot[ind][2]
if img_bin_curved is not None:
img_bin_in = imgs_tot[ind][3]
if abs(ori_in)<45:
img_in_des = rotate_image_with_padding(img_in, ori_in, border_value=(255,255,255) )
if img_bin_curved is not None:
img_bin_in_des = rotate_image_with_padding(img_bin_in, ori_in, border_value=(255,255,255) )
mask_in_des = rotate_image_with_padding(mask_in, ori_in)
mask_in_des = mask_in_des.astype('uint8')
#new bounding box
x_n, y_n, w_n, h_n = get_contours_and_bounding_boxes(mask_in_des[:,:,0])
if w_n==0 or h_n==0:
img_in_des = np.copy(img_in)
if img_bin_curved is not None:
img_bin_in_des = np.copy(img_bin_in)
w_relative = int(32 * img_in_des.shape[1]/float(img_in_des.shape[0]) )
if w_relative==0:
w_relative = img_in_des.shape[1]
img_in_des = resize_image(img_in_des, 32, w_relative)
if img_bin_curved is not None:
img_bin_in_des = resize_image(img_bin_in_des, 32, w_relative)
else:
mask_in_des = mask_in_des[y_n:y_n+h_n, x_n:x_n+w_n, :]
img_in_des = img_in_des[y_n:y_n+h_n, x_n:x_n+w_n, :]
if img_bin_curved is not None:
img_bin_in_des = img_bin_in_des[y_n:y_n+h_n, x_n:x_n+w_n, :]
w_relative = int(32 * img_in_des.shape[1]/float(img_in_des.shape[0]) )
if w_relative==0:
w_relative = img_in_des.shape[1]
img_in_des = resize_image(img_in_des, 32, w_relative)
if img_bin_curved is not None:
img_bin_in_des = resize_image(img_bin_in_des, 32, w_relative)
else:
img_in_des = np.copy(img_in)
if img_bin_curved is not None:
img_bin_in_des = np.copy(img_bin_in)
w_relative = int(32 * img_in_des.shape[1]/float(img_in_des.shape[0]) )
if w_relative==0:
w_relative = img_in_des.shape[1]
img_in_des = resize_image(img_in_des, 32, w_relative)
if img_bin_curved is not None:
img_bin_in_des = resize_image(img_bin_in_des, 32, w_relative)
w_tot_des+=img_in_des.shape[1]
w_tot_des_list.append(img_in_des.shape[1])
imgs_deskewed_list.append(img_in_des)
if img_bin_curved is not None:
imgs_bin_deskewed_list.append(img_bin_in_des)
img_final_deskewed = np.zeros((32, w_tot_des, 3))+255
if img_bin_curved is not None:
img_bin_final_deskewed = np.zeros((32, w_tot_des, 3))+255
else:
img_bin_final_deskewed = None
w_indexer = 0
for ind in range(len(w_tot_des_list)):
img_final_deskewed[:,w_indexer:w_indexer+w_tot_des_list[ind],:] = imgs_deskewed_list[ind][:,:,:]
if img_bin_curved is not None:
img_bin_final_deskewed[:,w_indexer:w_indexer+w_tot_des_list[ind],:] = imgs_bin_deskewed_list[ind][:,:,:]
w_indexer = w_indexer+w_tot_des_list[ind]
return img_final_deskewed, img_bin_final_deskewed
else:
return img_curved, img_bin_curved
def return_textline_contour_with_added_box_coordinate(textline_contour, box_ind):
textline_contour[:,0] = textline_contour[:,0] + box_ind[2]
textline_contour[:,1] = textline_contour[:,1] + box_ind[0]
return textline_contour
def return_rnn_cnn_ocr_of_given_textlines(image, all_found_textline_polygons, prediction_model, b_s_ocr, num_to_char, textline_light=False, curved_line=False):
max_len = 512
padding_token = 299
image_width = 512#max_len * 4
image_height = 32
ind_tot = 0
#cv2.imwrite('./img_out.png', image_page)
ocr_all_textlines = []
cropped_lines_region_indexer = []
cropped_lines_meging_indexing = []
cropped_lines = []
indexer_text_region = 0
for indexing, ind_poly_first in enumerate(all_found_textline_polygons):
#ocr_textline_in_textregion = []
if len(ind_poly_first)==0:
cropped_lines_region_indexer.append(indexer_text_region)
cropped_lines_meging_indexing.append(0)
img_fin = np.ones((image_height, image_width, 3))*1
cropped_lines.append(img_fin)
else:
for indexing2, ind_poly in enumerate(ind_poly_first):
cropped_lines_region_indexer.append(indexer_text_region)
if not (textline_light or curved_line):
ind_poly = copy.deepcopy(ind_poly)
box_ind = all_box_coord[indexing]
ind_poly = return_textline_contour_with_added_box_coordinate(ind_poly, box_ind)
#print(ind_poly_copy)
ind_poly[ind_poly<0] = 0
x, y, w, h = cv2.boundingRect(ind_poly)
w_scaled = w * image_height/float(h)
mask_poly = np.zeros(image.shape)
img_poly_on_img = np.copy(image)
mask_poly = cv2.fillPoly(mask_poly, pts=[ind_poly], color=(1, 1, 1))
mask_poly = mask_poly[y:y+h, x:x+w, :]
img_crop = img_poly_on_img[y:y+h, x:x+w, :]
img_crop[mask_poly==0] = 255
if w_scaled < 640:#1.5*image_width:
img_fin = preprocess_and_resize_image_for_ocrcnn_model(img_crop, image_height, image_width)
cropped_lines.append(img_fin)
cropped_lines_meging_indexing.append(0)
else:
splited_images, splited_images_bin = return_textlines_split_if_needed(img_crop, None)
if splited_images:
img_fin = preprocess_and_resize_image_for_ocrcnn_model(splited_images[0], image_height, image_width)
cropped_lines.append(img_fin)
cropped_lines_meging_indexing.append(1)
img_fin = preprocess_and_resize_image_for_ocrcnn_model(splited_images[1], image_height, image_width)
cropped_lines.append(img_fin)
cropped_lines_meging_indexing.append(-1)
else:
img_fin = preprocess_and_resize_image_for_ocrcnn_model(img_crop, image_height, image_width)
cropped_lines.append(img_fin)
cropped_lines_meging_indexing.append(0)
indexer_text_region+=1
extracted_texts = []
n_iterations = math.ceil(len(cropped_lines) / b_s_ocr)
for i in range(n_iterations):
if i==(n_iterations-1):
n_start = i*b_s_ocr
imgs = cropped_lines[n_start:]
imgs = np.array(imgs)
imgs = imgs.reshape(imgs.shape[0], image_height, image_width, 3)
else:
n_start = i*b_s_ocr
n_end = (i+1)*b_s_ocr
imgs = cropped_lines[n_start:n_end]
imgs = np.array(imgs).reshape(b_s_ocr, image_height, image_width, 3)
preds = prediction_model.predict(imgs, verbose=0)
pred_texts = decode_batch_predictions(preds, num_to_char)
for ib in range(imgs.shape[0]):
pred_texts_ib = pred_texts[ib].replace("[UNK]", "")
extracted_texts.append(pred_texts_ib)
extracted_texts_merged = [extracted_texts[ind] if cropped_lines_meging_indexing[ind]==0 else extracted_texts[ind]+" "+extracted_texts[ind+1] if cropped_lines_meging_indexing[ind]==1 else None for ind in range(len(cropped_lines_meging_indexing))]
extracted_texts_merged = [ind for ind in extracted_texts_merged if ind is not None]
unique_cropped_lines_region_indexer = np.unique(cropped_lines_region_indexer)
ocr_all_textlines = []
for ind in unique_cropped_lines_region_indexer:
ocr_textline_in_textregion = []
extracted_texts_merged_un = np.array(extracted_texts_merged)[np.array(cropped_lines_region_indexer)==ind]
for it_ind, text_textline in enumerate(extracted_texts_merged_un):
ocr_textline_in_textregion.append(text_textline)
ocr_all_textlines.append(ocr_textline_in_textregion)
return ocr_all_textlines
def biopython_align(str1, str2):
alignments = pairwise2.align.globalms(str1, str2, 2, -1, -2, -2)
best_alignment = alignments[0] # Get the best alignment
return best_alignment.seqA, best_alignment.seqB