Updates and fixes, working in Python 3.10

page_dewarp.py

@@ -348,13 +348,20 @@ def blob_mean_and_tangent(contour):
 
     area = moments['m00']
 
-    mean_x = moments['m10'] / area
-    mean_y = moments['m01'] / area
-
-    moments_matrix = np.array([
-        [moments['mu20'], moments['mu11']],
-        [moments['mu11'], moments['mu02']]
-    ]) / area
+    if area != 0:
+        mean_x = moments['m10'] / area
+        mean_y = moments['m01'] / area
+
+        moments_matrix = np.array([
+            [moments['mu20'], moments['mu11']],
+            [moments['mu11'], moments['mu02']]
+        ]) / area
+    else:
+        mean_x = mean_y = 0
+        moments_matrix = np.array([
+            [0.0, 0.0],
+            [0.0, 0.0]
+        ])
 
     _, svd_u, _ = cv2.SVDecomp(moments_matrix)
 
@@ -445,9 +452,11 @@ def make_tight_mask(contour, xmin, ymin, width, height):
 def get_contours(name, small, pagemask, masktype):
 
     mask = get_mask(name, small, pagemask, masktype)
+    # In some environments/versions, cv2.findContours apparently returns a 2-tuple instead of 3-tuple
+    # https://github.com/facebookresearch/maskrcnn-benchmark/issues/339
+    # We are always interested in the second-to-last member (first or second member) of the tuple
 
-    _, contours, _ = cv2.findContours(mask, cv2.RETR_EXTERNAL,
-                                      cv2.CHAIN_APPROX_NONE)
+    contours = cv2.findContours(mask, cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_NONE)[-2]
 
     contours_out = []
 
@@ -554,7 +563,7 @@ def sample_spans(shape, spans):
             xmin, ymin = cinfo.rect[:2]
 
             step = SPAN_PX_PER_STEP
-            start = ((len(means)-1) % step) / 2
+            start = int(((len(means)-1) % step) / 2)  #error => cast float to int
 
             contour_points += [(x+xmin, means[x]+ymin)
                                for x in range(start, len(means), step)]
@@ -670,7 +679,7 @@ def visualize_spans(name, small, pagemask, spans):
 
     display = small.copy()
     display[mask] = (display[mask]/2) + (regions[mask]/2)
-    display[pagemask == 0] /= 4
+    display[pagemask == 0] //= 4
 
     debug_show(name, 2, 'spans', display)
 
@@ -736,20 +745,20 @@ def objective(pvec):
         ppts = project_keypoints(pvec, keypoint_index)
         return np.sum((dstpoints - ppts)**2)
 
-    print '  initial objective is', objective(params)
+    print ('  initial objective is', objective(params))
 
     if DEBUG_LEVEL >= 1:
         projpts = project_keypoints(params, keypoint_index)
         display = draw_correspondences(small, dstpoints, projpts)
         debug_show(name, 4, 'keypoints before', display)
 
-    print '  optimizing', len(params), 'parameters...'
+    print ('  optimizing', len(params), 'parameters...')
     start = datetime.datetime.now()
     res = scipy.optimize.minimize(objective, params,
-                                  method='Powell')
+                                  method='SLSQP')
     end = datetime.datetime.now()
-    print '  optimization took', round((end-start).total_seconds(), 2), 'sec.'
-    print '  final objective is', res.fun
+    print ('  optimization took', round((end-start).total_seconds(), 2), 'sec.')
+    print ('  final objective is', res.fun)
     params = res.x
 
     if DEBUG_LEVEL >= 1:
@@ -773,7 +782,7 @@ def objective(dims):
     res = scipy.optimize.minimize(objective, dims, method='Powell')
     dims = res.x
 
-    print '  got page dims', dims[0], 'x', dims[1]
+    print ('  got page dims', dims[0], 'x', dims[1])
 
     return dims
 
@@ -786,13 +795,13 @@ def remap_image(name, img, small, page_dims, params):
     width = round_nearest_multiple(height * page_dims[0] / page_dims[1],
                                    REMAP_DECIMATE)
 
-    print '  output will be {}x{}'.format(width, height)
+    print ('  output will be {}x{}'.format(width, height))
 
     height_small = height / REMAP_DECIMATE
     width_small = width / REMAP_DECIMATE
 
-    page_x_range = np.linspace(0, page_dims[0], width_small)
-    page_y_range = np.linspace(0, page_dims[1], height_small)
+    page_x_range = np.linspace(0, page_dims[0], int(width_small))  #error => cast float to int
+    page_y_range = np.linspace(0, page_dims[1], int(height_small)) #error => cast float to int
 
     page_x_coords, page_y_coords = np.meshgrid(page_x_range, page_y_range)
 
@@ -820,7 +829,7 @@ def remap_image(name, img, small, page_dims, params):
                          None, cv2.BORDER_REPLICATE)
 
     thresh = cv2.adaptiveThreshold(remapped, 255, cv2.ADAPTIVE_THRESH_MEAN_C,
-                                   cv2.THRESH_BINARY, ADAPTIVE_WINSZ, 25)
+                                   cv2.THRESH_BINARY, ADAPTIVE_WINSZ, 17)
 
     pil_image = Image.fromarray(thresh)
     pil_image = pil_image.convert('1')
@@ -841,7 +850,7 @@ def remap_image(name, img, small, page_dims, params):
 def main():
 
     if len(sys.argv) < 2:
-        print 'usage:', sys.argv[0], 'IMAGE1 [IMAGE2 ...]'
+        print ('usage:', sys.argv[0], 'IMAGE1 [IMAGE2 ...]')
         sys.exit(0)
 
     if DEBUG_LEVEL > 0 and DEBUG_OUTPUT != 'file':
@@ -856,8 +865,7 @@ def main():
         basename = os.path.basename(imgfile)
         name, _ = os.path.splitext(basename)
 
-        print 'loaded', basename, 'with size', imgsize(img),
-        print 'and resized to', imgsize(small)
+        print ('loaded', basename, 'with size', imgsize(img),'\nand resized to', imgsize(small))
 
         if DEBUG_LEVEL >= 3:
             debug_show(name, 0.0, 'original', small)
@@ -868,20 +876,19 @@ def main():
         spans = assemble_spans(name, small, pagemask, cinfo_list)
 
         if len(spans) < 3:
-            print '  detecting lines because only', len(spans), 'text spans'
+            print ('  detecting lines because only', len(spans), 'text spans')
             cinfo_list = get_contours(name, small, pagemask, 'line')
             spans2 = assemble_spans(name, small, pagemask, cinfo_list)
             if len(spans2) > len(spans):
                 spans = spans2
 
         if len(spans) < 1:
-            print 'skipping', name, 'because only', len(spans), 'spans'
+            print ('skipping', name, 'because only', len(spans), 'spans')
             continue
 
         span_points = sample_spans(small.shape, spans)
 
-        print '  got', len(spans), 'spans',
-        print 'with', sum([len(pts) for pts in span_points]), 'points.'
+        print ('  got', len(spans), 'spans','\nwith', sum([len(pts) for pts in span_points]), 'points.')
 
         corners, ycoords, xcoords = keypoints_from_samples(name, small,
                                                            pagemask,
@@ -904,12 +911,97 @@ def main():
 
         outfiles.append(outfile)
 
-        print '  wrote', outfile
-        print
+        print ('  wrote', outfile)
+        print("")
+
+    print ('to convert to PDF (requires ImageMagick):')
+    print ('  convert -compress Group4 ' + ' '.join(outfiles) + ' output.pdf')
+
+def dewarp(name, img):
+
+    small = resize_to_screen(img)
+
+    pagemask, page_outline = get_page_extents(small)
+
+    cinfo_list = get_contours(name, small, pagemask, 'text')
+    spans = assemble_spans(name, small, pagemask, cinfo_list)
+
+    if len(spans) < 3:
+        print ('  detecting lines because only', len(spans), 'text spans')
+        cinfo_list = get_contours(name, small, pagemask, 'line')
+        spans2 = assemble_spans(name, small, pagemask, cinfo_list)
+        if len(spans2) > len(spans):
+            spans = spans2
+
+    if len(spans) < 1:
+        print ('skipping', name, 'because only', len(spans), 'spans')
+        return None
+
+    span_points = sample_spans(small.shape, spans)
+
+    corners, ycoords, xcoords = keypoints_from_samples(name, small,
+                                                        pagemask,
+                                                        page_outline,
+                                                        span_points)
+
+    rough_dims, span_counts, params = get_default_params(corners,
+                                                            ycoords, xcoords)
+
+    dstpoints = np.vstack((corners[0].reshape((1, 1, 2)),) +
+                            tuple(span_points))
 
-    print 'to convert to PDF (requires ImageMagick):'
-    print '  convert -compress Group4 ' + ' '.join(outfiles) + ' output.pdf'
+    params = optimize_params(name, small,
+                                dstpoints,
+                                span_counts, params)
+
+    page_dims = get_page_dims(corners, rough_dims, params)
 
+    outfile = remap_image(name, img, small, page_dims, params)
+
+    return outfile
+
+def is_curve(name, img):
+
+    small = resize_to_screen(img)
+
+    pagemask, page_outline = get_page_extents(small)
+
+    cinfo_list = get_contours(name, small, pagemask, 'text')
+    spans = assemble_spans(name, small, pagemask, cinfo_list)
+
+    if len(spans) < 3:
+        print ('  detecting lines because only', len(spans), 'text spans')
+        cinfo_list = get_contours(name, small, pagemask, 'line')
+        spans2 = assemble_spans(name, small, pagemask, cinfo_list)
+        if len(spans2) > len(spans):
+            spans = spans2
+
+    if len(spans) < 1:
+        print ('skipping', name, 'because only', len(spans), 'spans')
+        return None
+
+    span_points = sample_spans(small.shape, spans)
+
+    corners, ycoords, xcoords = keypoints_from_samples(name, small,
+                                                        pagemask,
+                                                        page_outline,
+                                                        span_points)
+
+    rough_dims, span_counts, params = get_default_params(corners,
+                                                            ycoords, xcoords)
+
+    dstpoints = np.vstack((corners[0].reshape((1, 1, 2)),) +
+                            tuple(span_points))
+
+    params = optimize_params(name, small,
+                                dstpoints,
+                                span_counts, params)
+
+    if abs(params[0]) < 0.1 and abs(params[1]) < 0.1 and abs(params[2]) < 0.1:
+        return True
+    else:
+        print(params[:8])
+        return False
 
 if __name__ == '__main__':
     main()

requirements.txt

@@ -1,5 +1,4 @@
-page_dewarp
-numpy
-scipy
-Image
-cv2>=3.0
+numpy>=1.21,<2
+scipy>=1.7,<2
+pillow>=8.4,<9
+opencv-python>=3.4,<4