get_marginals(): simplify, improve…

- rename `thickness_along_y_percent` →
  `max_textline_thickness_percent`
- rename `marginlas_should_be_main_text` →
  `main_text_should_be_marginals`
- constrain `find_peaks()` by prominence and distance
- simplify (a lot)
- add comments for possible improvements
  and for plotting
This commit is contained in:
Robert Sachunsky 2026-04-25 01:52:21 +02:00
parent bb092364af
commit 70bf461c30

View file

@ -7,165 +7,159 @@ from .resize import resize_image
from .rotate import rotate_image from .rotate import rotate_image
def get_marginals(text_with_lines, text_regions, num_col, slope_deskew, kernel=None): def get_marginals(text_with_lines, text_regions, num_col, slope_deskew, kernel=None):
mask_marginals=np.zeros((text_with_lines.shape[0],text_with_lines.shape[1])) # rs: text_with_lines should be called text_mask_d
mask_marginals=mask_marginals.astype(np.uint8) # rs: text_regions should be called early_layout (contains other classes, too)
# rs: text_with_lines is already deskewed, while text_regions is not...
mask_marginals = np.zeros_like(text_with_lines)
height, width = mask_marginals.shape
text_with_lines=text_with_lines.astype(np.uint8)
##text_with_lines=cv2.erode(text_with_lines,self.kernel,iterations=3) ##text_with_lines=cv2.erode(text_with_lines,self.kernel,iterations=3)
text_with_lines_eroded = cv2.erode(text_with_lines,kernel,iterations=5) text_with_lines_eroded = cv2.erode(text_with_lines,kernel,iterations=5)
if text_with_lines.shape[0]<=1500: if height <= 1500:
pass pass
elif text_with_lines.shape[0]>1500 and text_with_lines.shape[0]<=1800: elif 1500 < height <= 1800:
text_with_lines=resize_image(text_with_lines,int(text_with_lines.shape[0]*1.5),text_with_lines.shape[1]) # rs: why not / 1.5???
text_with_lines = resize_image(text_with_lines, int(height * 1.5), width)
text_with_lines = cv2.erode(text_with_lines, kernel, iterations=5) text_with_lines = cv2.erode(text_with_lines, kernel, iterations=5)
text_with_lines=resize_image(text_with_lines,text_with_lines_eroded.shape[0],text_with_lines_eroded.shape[1]) # rs: and back to original size
text_with_lines = resize_image(text_with_lines, height, width)
else: else:
text_with_lines=resize_image(text_with_lines,int(text_with_lines.shape[0]*1.8),text_with_lines.shape[1]) # rs: why not / 1.8???
text_with_lines = resize_image(text_with_lines, int(height * 1.8), width)
text_with_lines = cv2.erode(text_with_lines, kernel, iterations=7) text_with_lines = cv2.erode(text_with_lines, kernel, iterations=7)
text_with_lines=resize_image(text_with_lines,text_with_lines_eroded.shape[0],text_with_lines_eroded.shape[1]) # rs: and back to original size
text_with_lines = resize_image(text_with_lines, height, width)
kernel_hor = np.ones((1, 5), dtype=np.uint8) kernel_hor = np.ones((1, 5), dtype=np.uint8)
text_with_lines = cv2.erode(text_with_lines, kernel_hor, iterations=6) text_with_lines = cv2.erode(text_with_lines, kernel_hor, iterations=6)
text_with_lines_y = text_with_lines.sum(axis=0) text_with_lines_y = text_with_lines.sum(axis=0)
text_with_lines_y_eroded = text_with_lines_eroded.sum(axis=0) text_with_lines_y_eroded = text_with_lines_eroded.sum(axis=0)
thickness_along_y_percent=text_with_lines_y_eroded.max()/(float(text_with_lines.shape[0]))*100 max_textline_thickness_percent = 100. * text_with_lines_y_eroded.max() / height
#print(thickness_along_y_percent,'thickness_along_y_percent') # rs: min_textline_thickness seems to be calibrated for some fixed resolution,
# but text_with_lines varies in size!
if thickness_along_y_percent<30: if max_textline_thickness_percent < 30:
min_textline_thickness = 8 min_textline_thickness = 8
elif thickness_along_y_percent>=30 and thickness_along_y_percent<50: elif max_textline_thickness_percent < 50:
min_textline_thickness = 20 min_textline_thickness = 20
else: else:
min_textline_thickness = 45 min_textline_thickness = 45
# min_textline_thickness = max_textline_thickness_percent / 100. * height / 20.
# plt.figure()
# ax1 = plt.subplot(2, 1, 1, title="text_with_lines_eroded")
# ax1.imshow(text_with_lines_eroded, aspect='auto')
# ax2 = plt.subplot(2, 1, 2, title="text_with_lines_y_eroded", sharex=ax1)
# ax2.plot(list(range(width)), text_with_lines_y_eroded)
# ax2.hlines(int(0.14 * height), 0, width,
# label='max_textline_thickness=14%', colors='r')
# ax2.hlines([min_textline_thickness], 0, width,
# label='min_textline_thickness', colors='g')
# ax2.scatter([np.argmax(text_with_lines_y_eroded)],
# [text_with_lines_y_eroded.max()], color='r',
# label='max = %d%%' % max_textline_thickness_percent)
# plt.legend()
# plt.show()
if thickness_along_y_percent>=14: if max_textline_thickness_percent >= 14:
text_with_lines_y_rev = np.max(text_with_lines_y) - text_with_lines_y
text_with_lines_y_rev=-1*text_with_lines_y[:]
text_with_lines_y_rev=text_with_lines_y_rev-np.min(text_with_lines_y_rev)
sigma_gaus=1
region_sum_0= gaussian_filter1d(text_with_lines_y, sigma_gaus)
region_sum_0_rev=gaussian_filter1d(text_with_lines_y_rev, sigma_gaus)
region_sum_0_updown=region_sum_0[len(region_sum_0)::-1]
first_nonzero=(next((i for i, x in enumerate(region_sum_0) if x), None))
last_nonzero=(next((i for i, x in enumerate(region_sum_0_updown) if x), None))
last_nonzero=len(region_sum_0)-last_nonzero
mid_point=(last_nonzero+first_nonzero)/2.
region_sum_0 = gaussian_filter1d(text_with_lines_y, 1)
first_nonzero = region_sum_0.nonzero()[0][0] # outer left
last_nonzero = region_sum_0.nonzero()[0][-1] # outer right
mid_point = 0.5 * (last_nonzero + first_nonzero)
one_third_right = (last_nonzero - mid_point) / 3.0 one_third_right = (last_nonzero - mid_point) / 3.0
one_third_left = (mid_point - first_nonzero) / 3.0 one_third_left = (mid_point - first_nonzero) / 3.0
peaks, _ = find_peaks(text_with_lines_y_rev, height=0) # rs: constrain the distance at least 2 characters at 12pt, retrieve height and prominence
peaks=np.array(peaks) peaks, props = find_peaks(text_with_lines_y_rev, height=0, prominence=0, distance=30)
peaks_orig = np.copy(peaks)
# rs: also calculate the product of prominence and height (for final selection)
scores = np.zeros(peaks.max() + 1)
scores[peaks] = props['prominences'] * props['peak_heights']
peaks = peaks[(peaks > first_nonzero) & (peaks < last_nonzero)] peaks = peaks[(peaks > first_nonzero) & (peaks < last_nonzero)]
peaks = peaks[region_sum_0[peaks] < min_textline_thickness] peaks = peaks[region_sum_0[peaks] < min_textline_thickness]
if num_col == 1: if num_col == 1:
peaks_right = peaks[peaks > mid_point] peaks_right = peaks[peaks > mid_point]
peaks_left = peaks[peaks < mid_point] peaks_left = peaks[peaks < mid_point]
if num_col == 2: if num_col == 2:
peaks_right=peaks[peaks>(mid_point+one_third_right)] peaks_right = peaks[peaks > mid_point + one_third_right]
peaks_left=peaks[peaks<(mid_point-one_third_left)] peaks_left = peaks[peaks < mid_point - one_third_left]
point_right = np.min(peaks_right, initial=last_nonzero)
try: point_left = np.max(peaks_left, initial=first_nonzero)
point_right=np.min(peaks_right) # rs: at least one peak must have been found
except: if point_right == last_nonzero and point_left == first_nonzero:
point_right=last_nonzero
try:
point_left=np.max(peaks_left)
except:
point_left=first_nonzero
if point_left == first_nonzero and point_right == last_nonzero:
return text_regions return text_regions
# rs: should be called mask_main (i.e. inverted semantics here)
if point_right>=mask_marginals.shape[1]:
point_right=mask_marginals.shape[1]-1
try:
mask_marginals[:, point_left: point_right] = 1 mask_marginals[:, point_left: point_right] = 1
except:
mask_marginals[:,:]=1
# plt.figure()
# ax1 = plt.subplot(2, 2, 1)
# ax1.title.set_text('text_with_lines (deskewed text+sep mask)')
# ax1.imshow(text_with_lines)
# ax1.vlines(peaks_left, 0, height, label='peaks_left', colors='b')
# ax1.vlines(peaks_right, 0, height, label='peaks_right', colors='b')
# ax1.vlines([first_nonzero], 0, height, label='first_nonzero', colors='g')
# ax1.vlines([last_nonzero], 0, height, label='last_nonzero', colors='g')
# ax1.vlines([point_left], 0, height, label='point_left', colors='r')
# ax1.vlines([point_right], 0, height, label='point_right', colors='r')
# ax2 = plt.subplot(2, 2, 2, title='mask_marginals (deskewed marginal mask)', sharey=ax1)
# ax2.imshow(mask_marginals)
# ax3 = plt.subplot(2, 2, 3, title='text_with_lines_y (projection for minima)', sharex=ax1)
# ax3.plot(list(range(width)), text_with_lines_y)
# ax3.set_aspect('auto')
# ax4 = plt.subplot(2, 2, 4, title='text_regions (undeskewed labels)')
# ax4.imshow(text_regions)
# plt.legend()
# plt.show()
# rs: rotate back (into undeskewed/original shape as text_regions input):
mask_marginals_rotated = rotate_image(mask_marginals, -slope_deskew) mask_marginals_rotated = rotate_image(mask_marginals, -slope_deskew)
mask_marginals_rotated_y = mask_marginals_rotated.sum(axis=0)
mask_marginals_rotated_y_nz = np.flatnonzero(mask_marginals_rotated_y)
min_point_of_left_marginal = max(0, np.min(mask_marginals_rotated_y_nz) - 16)
max_point_of_right_marginal = min(width - 1, np.max(mask_marginals_rotated_y_nz) + 16)
mask_marginals_rotated_sum=mask_marginals_rotated.sum(axis=0)
mask_marginals_rotated_sum[mask_marginals_rotated_sum!=0]=1
index_x=np.array(range(len(mask_marginals_rotated_sum)))+1
index_x_interest=index_x[mask_marginals_rotated_sum==1]
min_point_of_left_marginal=np.min(index_x_interest)-16
max_point_of_right_marginal=np.max(index_x_interest)+16
if min_point_of_left_marginal<0:
min_point_of_left_marginal=0
if max_point_of_right_marginal>=text_regions.shape[1]:
max_point_of_right_marginal=text_regions.shape[1]-1
text_regions_org = np.copy(text_regions)
text_regions[text_regions[:,:]==1]=4
pixel_img=4
min_area_text = 0.00001 min_area_text = 0.00001
# rs: why not extract from mask_marginals_rotated???
# rs: why not largest area instead of first?
polygon_mask_marginals_rotated = return_contours_of_interested_region(mask_marginals, 1, min_area_text)[0]
polygons_of_marginals = return_contours_of_interested_region(text_regions, 1, min_area_text)
polygon_mask_marginals_rotated = return_contours_of_interested_region(mask_marginals,1,min_area_text) (cx_text_only,
cy_text_only,
polygon_mask_marginals_rotated = polygon_mask_marginals_rotated[0] x_min_text_only,
x_max_text_only,
polygons_of_marginals=return_contours_of_interested_region(text_regions,pixel_img,min_area_text) y_min_text_only,
y_max_text_only,
cx_text_only,cy_text_only ,x_min_text_only,x_max_text_only, y_min_text_only ,y_max_text_only,y_cor_x_min_main=find_new_features_of_contours(polygons_of_marginals) y_cor_x_min_main) = find_new_features_of_contours(polygons_of_marginals)
text_regions[(text_regions[:,:]==4)]=1
marginlas_should_be_main_text=[]
main_text_should_be_marginals = []
x_min_marginals_left=[] x_min_marginals_left=[]
x_min_marginals_right=[] x_min_marginals_right=[]
for i in range(len(cx_text_only)): for i, polygon in enumerate(polygons_of_marginals):
results = cv2.pointPolygonTest(polygon_mask_marginals_rotated, (cx_text_only[i], cy_text_only[i]), False) if -1 == cv2.pointPolygonTest(polygon_mask_marginals_rotated,
(cx_text_only[i],
cy_text_only[i]),
False):
main_text_should_be_marginals.append(polygon)
if results == -1: text_regions = cv2.fillPoly(text_regions, pts=main_text_should_be_marginals, color=4)
marginlas_should_be_main_text.append(polygons_of_marginals[i]) # plt.figure()
# ax1 = plt.subplot(2, 2, 1, title='mask_marginals (deskewed marginal mask)')
# plt.imshow(mask_marginals)
# ax2 = plt.subplot(2, 2, 2, title='mask_marginals_rotated (undeskewed marginal mask)')
text_regions_org=cv2.fillPoly(text_regions_org, pts =marginlas_should_be_main_text, color=(4,4)) # plt.imshow(mask_marginals_rotated)
text_regions = np.copy(text_regions_org) # ax4 = plt.subplot(2, 2, 4, title='text_regions (undeskewed labels split)')
# plt.imshow(text_regions)
###text_regions[:,0:point_left][text_regions[:,0:point_left]==1]=4
###text_regions[:,point_right:][ text_regions[:,point_right:]==1]=4
#plt.plot(region_sum_0)
#plt.plot(peaks,region_sum_0[peaks],'*')
# plt.show() # plt.show()
#plt.imshow(text_regions) #plt.imshow(text_regions)
#plt.show() #plt.show()