switch from (ad-hoc) mp.Pool to (attribute) concurrent.futures.ProcessPoolExecutor

src/eynollah/eynollah.py

@@ -13,7 +13,8 @@ import time
 import warnings
 from functools import partial
 from pathlib import Path
-from multiprocessing import Pool, cpu_count
+from multiprocessing import cpu_count
+from concurrent.futures import ProcessPoolExecutor
 import gc
 from ocrd_utils import getLogger
 import cv2
@@ -251,6 +252,8 @@ class Eynollah:
                 textline_light = self.textline_light,
                 pcgts=pcgts)
         self.logger = logger if logger else getLogger('eynollah')
+        # for parallelization of CPU-intensive tasks:
+        self.executor = ProcessPoolExecutor(max_workers=cpu_count())
         self.dir_models = dir_models
         self.model_dir_of_enhancement = dir_models + "/eynollah-enhancement_20210425"
         self.model_dir_of_binarization = dir_models + "/eynollah-binarization_20210425"
@@ -1518,21 +1521,15 @@ class Eynollah:
         if not len(contours):
             return [], [], [], [], [], [], []
         self.logger.debug("enter get_slopes_and_deskew_new_light")
-        if len(contours)>15:
-            num_cores = cpu_count()
-        else:
-            num_cores = 1
-        with Pool(processes=num_cores) as pool:
-            results = pool.starmap(
-                partial(do_work_of_slopes_new_light,
+        results = self.executor.map(partial(do_work_of_slopes_new_light,
                                             textline_mask_tot_ea=textline_mask_tot,
                                             image_page_rotated=image_page_rotated,
                                             slope_deskew=slope_deskew,
-                        logger=self.logger,
                                             MAX_SLOPE=MAX_SLOPE,
                                             KERNEL=KERNEL,
+                                            logger=self.logger,
                                             plotter=self.plotter,),
-                zip(boxes, contours, contours_par, range(len(contours_par))))
+                                    boxes, contours, contours_par, range(len(contours_par)))
         #textline_polygons, boxes, text_regions, text_regions_par, box_coord, index_text_con, slopes = zip(*results)
         self.logger.debug("exit get_slopes_and_deskew_new_light")
         return tuple(zip(*results))
@@ -1541,18 +1538,15 @@ class Eynollah:
         if not len(contours):
             return [], [], [], [], [], [], []
         self.logger.debug("enter get_slopes_and_deskew_new")
-        num_cores = cpu_count()
-        with Pool(processes=num_cores) as pool:
-            results = pool.starmap(
-                partial(do_work_of_slopes_new,
+        results = self.executor.map(partial(do_work_of_slopes_new,
                                             textline_mask_tot_ea=textline_mask_tot,
                                             image_page_rotated=image_page_rotated,
                                             slope_deskew=slope_deskew,
-                        logger=self.logger,
                                             MAX_SLOPE=MAX_SLOPE,
                                             KERNEL=KERNEL,
+                                            logger=self.logger,
                                             plotter=self.plotter,),
-                zip(boxes, contours, contours_par, range(len(contours_par))))
+                                    boxes, contours, contours_par, range(len(contours_par)))
         #textline_polygons, boxes, text_regions, text_regions_par, box_coord, index_text_con, slopes = zip(*results)
         self.logger.debug("exit get_slopes_and_deskew_new")
         return tuple(zip(*results))
@@ -1561,21 +1555,18 @@ class Eynollah:
         if not len(contours):
             return [], [], [], [], [], [], []
         self.logger.debug("enter get_slopes_and_deskew_new_curved")
-        num_cores = cpu_count()
-        with Pool(processes=num_cores) as pool:
-            results = pool.starmap(
-                partial(do_work_of_slopes_new_curved,
+        results = self.executor.map(partial(do_work_of_slopes_new_curved,
                                             textline_mask_tot_ea=textline_mask_tot,
                                             image_page_rotated=image_page_rotated,
                                             mask_texts_only=mask_texts_only,
                                             num_col=num_col,
                                             scale_par=scale_par,
                                             slope_deskew=slope_deskew,
-                        logger=self.logger,
                                             MAX_SLOPE=MAX_SLOPE,
                                             KERNEL=KERNEL,
+                                            logger=self.logger,
                                             plotter=self.plotter,),
-                zip(boxes, contours, contours_par, range(len(contours_par))))
+                                    boxes, contours, contours_par, range(len(contours_par)))
         #textline_polygons, boxes, text_regions, text_regions_par, box_coord, index_text_con, slopes = zip(*results)
         self.logger.debug("exit get_slopes_and_deskew_new_curved")
         return tuple(zip(*results))
@@ -1643,7 +1634,8 @@ class Eynollah:
                 y_diff_mean = find_contours_mean_y_diff(textline_con_fil)
                 sigma_des = max(1, int(y_diff_mean * (4.0 / 40.0)))
                 crop_img[crop_img > 0] = 1
-                slope_corresponding_textregion = return_deskew_slop(crop_img, sigma_des, plotter=self.plotter)
+                slope_corresponding_textregion = return_deskew_slop(crop_img, sigma_des,
+                                                                    map=self.executor.map, logger=self.logger, plotter=self.plotter)
             except Exception as why:
                 self.logger.error(why)
                 slope_corresponding_textregion = MAX_SLOPE
@@ -2932,10 +2924,8 @@ class Eynollah:
 
     def run_deskew(self, textline_mask_tot_ea):
         #print(textline_mask_tot_ea.shape, 'textline_mask_tot_ea deskew')
-        sigma = 2
-        main_page_deskew = True
-        n_total_angles = 30
-        slope_deskew = return_deskew_slop(cv2.erode(textline_mask_tot_ea, KERNEL, iterations=2), sigma, n_total_angles, main_page_deskew, plotter=self.plotter)
+        slope_deskew = return_deskew_slop(cv2.erode(textline_mask_tot_ea, KERNEL, iterations=2), 2, 30, True,
+                                          map=self.executor.map, logger=self.logger, plotter=self.plotter)
         slope_first = 0
 
         if self.plotter:
@@ -4748,7 +4738,7 @@ class Eynollah:
                 contours_only_text_parent = self.dilate_textregions_contours(contours_only_text_parent)
                 contours_only_text_parent = self.filter_contours_inside_a_bigger_one(contours_only_text_parent, text_only, marginal_cnts=polygons_of_marginals)
                 #print("text region early 3.5 in %.1fs", time.time() - t0)
-                txt_con_org = get_textregion_contours_in_org_image_light(contours_only_text_parent, self.image, slope_first)
+                txt_con_org = get_textregion_contours_in_org_image_light(contours_only_text_parent, self.image, slope_first, map=self.executor.map)
                 #txt_con_org = self.dilate_textregions_contours(txt_con_org)
                 #contours_only_text_parent = self.dilate_textregions_contours(contours_only_text_parent)
             else:

src/eynollah/utils/contour.py

@@ -1,5 +1,4 @@
 from functools import partial
-from multiprocessing import cpu_count, Pool
 import cv2
 import numpy as np
 from shapely import geometry
@@ -162,17 +161,14 @@ def do_work_of_contours_in_image(contour, index_r_con, img, slope_first):
 
     return cont_int[0], index_r_con
 
-def get_textregion_contours_in_org_image_multi(cnts, img, slope_first):
+def get_textregion_contours_in_org_image_multi(cnts, img, slope_first, map=map):
     if not len(cnts):
         return [], []
-    num_cores = cpu_count()
-    with Pool(processes=num_cores) as pool:
-        results = pool.starmap(
-            partial(do_work_of_contours_in_image,
+    results = map(partial(do_work_of_contours_in_image,
                           img=img,
                           slope_first=slope_first,
                           ),
-            zip(cnts, range(len(cnts))))
+                  cnts, range(len(cnts)))
     return tuple(zip(*results))
 
 def get_textregion_contours_in_org_image(cnts, img, slope_first):
@@ -252,21 +248,18 @@ def do_back_rotation_and_get_cnt_back(contour_par, index_r_con, img, slope_first
     # print(np.shape(cont_int[0]))
     return cont_int[0], index_r_con
 
-def get_textregion_contours_in_org_image_light(cnts, img, slope_first):
+def get_textregion_contours_in_org_image_light(cnts, img, slope_first, map=map):
     if not len(cnts):
         return []
     img = cv2.resize(img, (int(img.shape[1]/6), int(img.shape[0]/6)), interpolation=cv2.INTER_NEAREST)
     ##cnts = list( (np.array(cnts)/2).astype(np.int16) )
     #cnts = cnts/2
     cnts = [(i/6).astype(np.int) for i in cnts]
-    num_cores = cpu_count()
-    with Pool(processes=num_cores) as pool:
-        results = pool.starmap(
-            partial(do_back_rotation_and_get_cnt_back,
+    results = map(partial(do_back_rotation_and_get_cnt_back,
                           img=img,
                           slope_first=slope_first,
                           ),
-            zip(cnts, range(len(cnts))))
+                  cnts, range(len(cnts)))
     contours, indexes = tuple(zip(*results))
     return [i*6 for i in contours]
 

src/eynollah/utils/separate_lines.py

@@ -1,6 +1,6 @@
 import os
+from logging import getLogger
 from functools import partial
-from multiprocessing import Pool, cpu_count
 import numpy as np
 import cv2
 from scipy.signal import find_peaks
@@ -1464,7 +1464,9 @@ def textline_contours_postprocessing(textline_mask, slope, contour_text_interest
 
     return contours_rotated_clean
 
-def separate_lines_new2(img_path, thetha, num_col, slope_region, plotter=None):
+def separate_lines_new2(img_path, thetha, num_col, slope_region, logger=None, plotter=None):
+    if logger is None:
+        logger = getLogger(__package__)
 
     if num_col == 1:
         num_patches = int(img_path.shape[1] / 200.0)
@@ -1572,18 +1574,20 @@ def separate_lines_new2(img_path, thetha, num_col, slope_region, plotter=None):
     # plt.show()
     return img_patch_ineterst_revised
 
-def do_image_rotation(angle, img, sigma_des):
-    print(f"rotating image by {angle}")
+def do_image_rotation(angle, img, sigma_des, logger=None):
+    if logger is None:
+        logger = getLogger(__package__)
     img_rot = rotate_image(img, angle)
     img_rot[img_rot!=0] = 1
     try:
         var = find_num_col_deskew(img_rot, sigma_des, 20.3)
     except:
+        logger.exception("cannot determine variance for angle %.2f°", angle)
         var = 0
     return var
 
-def return_deskew_slop(img_patch_org, sigma_des,n_tot_angles=100, main_page=False, plotter=None):
-    num_cores = cpu_count()
+def return_deskew_slop(img_patch_org, sigma_des,n_tot_angles=100,
+                       main_page=False, logger=None, plotter=None, map=map):
     if main_page and plotter:
         plotter.save_plot_of_textline_density(img_patch_org)
 
@@ -1615,16 +1619,16 @@ def return_deskew_slop(img_patch_org, sigma_des,n_tot_angles=100, main_page=Fals
         #plt.imshow(img_resized)
         #plt.show()
         angles = np.array([-45, 0, 45, 90,])
-        angle = get_smallest_skew(img_resized, sigma_des, angles, num_cores=num_cores, plotter=plotter)
+        angle = get_smallest_skew(img_resized, sigma_des, angles, map=map, logger=logger, plotter=plotter)
 
         angles = np.linspace(angle - 22.5, angle + 22.5, n_tot_angles)
-        angle = get_smallest_skew(img_resized, sigma_des, angles, num_cores=num_cores, plotter=plotter)
+        angle = get_smallest_skew(img_resized, sigma_des, angles, map=map, logger=logger, plotter=plotter)
         
     elif main_page:
         #plt.imshow(img_resized)
         #plt.show()
         angles = np.linspace(-12, 12, n_tot_angles)#np.array([0 , 45 , 90 , -45])
-        angle = get_smallest_skew(img_resized, sigma_des, angles, num_cores=num_cores, plotter=plotter)
+        angle = get_smallest_skew(img_resized, sigma_des, angles, map=map, logger=logger, plotter=plotter)
 
         early_slope_edge=11
         if abs(angle) > early_slope_edge:
@@ -1632,11 +1636,11 @@ def return_deskew_slop(img_patch_org, sigma_des,n_tot_angles=100, main_page=Fals
                 angles = np.linspace(-90, -12, n_tot_angles)
             else:
                 angles = np.linspace(90, 12, n_tot_angles)
-            angle = get_smallest_skew(img_resized, sigma_des, angles, num_cores=num_cores, plotter=plotter)
+            angle = get_smallest_skew(img_resized, sigma_des, angles, map=map, logger=logger, plotter=plotter)
 
     else:
         angles = np.linspace(-25, 25, int(0.5 * n_tot_angles) + 10)
-        angle = get_smallest_skew(img_resized, sigma_des, angles, num_cores=num_cores, plotter=plotter)
+        angle = get_smallest_skew(img_resized, sigma_des, angles, map=map, logger=logger, plotter=plotter)
 
         early_slope_edge=22
         if abs(angle) > early_slope_edge:
@@ -1644,30 +1648,35 @@ def return_deskew_slop(img_patch_org, sigma_des,n_tot_angles=100, main_page=Fals
                 angles = np.linspace(-90, -25, int(0.5 * n_tot_angles) + 10)
             else:
                 angles = np.linspace(90, 25, int(0.5 * n_tot_angles) + 10)
-            angle = get_smallest_skew(img_resized, sigma_des, angles, num_cores=num_cores, plotter=plotter)
+            angle = get_smallest_skew(img_resized, sigma_des, angles, map=map, logger=logger, plotter=plotter)
 
     return angle
 
-def get_smallest_skew(img, sigma_des, angles, num_cores=1, plotter=None):
-    with Pool(processes=num_cores) as pool:
-        results = pool.map(partial(do_image_rotation, img=img, sigma_des=sigma_des), angles)
+def get_smallest_skew(img, sigma_des, angles, logger=None, plotter=None, map=map):
+    if logger is None:
+        logger = getLogger(__package__)
+    results = list(map(partial(do_image_rotation, img=img, sigma_des=sigma_des, logger=logger), angles))
     if plotter:
         plotter.save_plot_of_rotation_angle(angles, results)
     try:
         var_res = np.array(results)
+        assert var_res.any()
         angle = angles[np.argmax(var_res)]
     except:
+        logger.exception("cannot determine best angle among %s", str(angles))
         angle = 0
     return angle
 
 def do_work_of_slopes_new(
         box_text, contour, contour_par, index_r_con,
         textline_mask_tot_ea, image_page_rotated, slope_deskew,
-        logger, MAX_SLOPE=999, KERNEL=None, plotter=None
+        logger=None, MAX_SLOPE=999, KERNEL=None, plotter=None
 ):
-    logger.debug('enter do_work_of_slopes_new')
     if KERNEL is None:
         KERNEL = np.ones((5, 5), np.uint8)
+    if logger is None:
+        logger = getLogger(__package__)
+    logger.debug('enter do_work_of_slopes_new')
 
     x, y, w, h = box_text
     _, crop_coor = crop_image_inside_box(box_text, image_page_rotated)
@@ -1693,11 +1702,11 @@ def do_work_of_slopes_new(
             else:
                 sigma_des = max(1, int(y_diff_mean * (4.0 / 40.0)))
                 img_int_p[img_int_p > 0] = 1
-                slope_for_all = return_deskew_slop(img_int_p, sigma_des, plotter=plotter)
+                slope_for_all = return_deskew_slop(img_int_p, sigma_des, logger=logger, plotter=plotter)
                 if abs(slope_for_all) <= 0.5:
                     slope_for_all = slope_deskew
-        except Exception as why:
-            logger.error(why)
+        except:
+            logger.exception("cannot determine angle of contours")
             slope_for_all = MAX_SLOPE
 
         if slope_for_all == MAX_SLOPE:
@@ -1728,11 +1737,13 @@ def do_work_of_slopes_new(
 def do_work_of_slopes_new_curved(
         box_text, contour, contour_par, index_r_con,
         textline_mask_tot_ea, image_page_rotated, mask_texts_only, num_col, scale_par, slope_deskew,
-        logger, MAX_SLOPE=999, KERNEL=None, plotter=None
+        logger=None, MAX_SLOPE=999, KERNEL=None, plotter=None
 ):
-    logger.debug("enter do_work_of_slopes_new_curved")
     if KERNEL is None:
         KERNEL = np.ones((5, 5), np.uint8)
+    if logger is None:
+        logger = getLogger(__package__)
+    logger.debug("enter do_work_of_slopes_new_curved")
 
     x, y, w, h = box_text
     all_text_region_raw = textline_mask_tot_ea[y: y + h, x: x + w].astype(np.uint8)
@@ -1755,11 +1766,11 @@ def do_work_of_slopes_new_curved(
             else:
                 sigma_des = max(1, int(y_diff_mean * (4.0 / 40.0)))
                 img_int_p[img_int_p > 0] = 1
-                slope_for_all = return_deskew_slop(img_int_p, sigma_des, plotter=plotter)
+                slope_for_all = return_deskew_slop(img_int_p, sigma_des, logger=logger, plotter=plotter)
                 if abs(slope_for_all) < 0.5:
                     slope_for_all = slope_deskew
-        except Exception as why:
-            logger.error(why)
+        except:
+            logger.exception("cannot determine angle of contours")
             slope_for_all = MAX_SLOPE
 
         if slope_for_all == MAX_SLOPE:
@@ -1778,7 +1789,7 @@ def do_work_of_slopes_new_curved(
 
         # print(slope_for_all,'slope_for_all')
         textline_rotated_separated = separate_lines_new2(textline_biggest_region[y: y+h, x: x+w], 0, num_col, slope_for_all,
-                                                         plotter=plotter)
+                                                         logger=logger, plotter=plotter)
 
         # new line added
         ##print(np.shape(textline_rotated_separated),np.shape(mask_biggest))
@@ -1818,8 +1829,10 @@ def do_work_of_slopes_new_curved(
 def do_work_of_slopes_new_light(
         box_text, contour, contour_par, index_r_con,
         textline_mask_tot_ea, image_page_rotated, slope_deskew,
-        logger
+        logger=None
 ):
+    if logger is None:
+        logger = getLogger(__package__)
     logger.debug('enter do_work_of_slopes_new_light')
 
     x, y, w, h = box_text