Adjust reading order when there are no columns

When there are no columns white separators and no black
columns separators, then we determine the reading order
by simply looking which line is above which other lines.

ocrolib/psegutils.py

@@ -121,7 +121,7 @@ def extract_masked(image,linedesc,pad=5,expand=0):
     line = where(mask,line,amax(line))
     return line
 
-def reading_order(lines,highlight=None,debug=0):
+def reading_order(lines,nocolumns=False,highlight=None,debug=0):
     """Given the list of lines (a list of 2D slices), computes
     the partial reading order.  The output is a binary 2D array
     such that order[i,j] is true if line i comes before line j
@@ -141,7 +141,7 @@ def reading_order(lines,highlight=None,debug=0):
         clf(); title("highlight"); imshow(binary); ginput(1,debug)
     for i,u in enumerate(lines):
         for j,v in enumerate(lines):
-            if x_overlaps(u,v):
+            if x_overlaps(u,v) or nocolumns:
                 if above(u,v):
                     order[i,j] = 1
             else:

ocropus-gpageseg

@@ -388,7 +388,10 @@ def process1(job):
 
     if not args.quiet: print_info("finding reading order")
     lines = psegutils.compute_lines(segmentation,scale)
-    order = psegutils.reading_order([l.bounds for l in lines])
+    if args.maxcolseps>0 or args.blackseps:
+        order = psegutils.reading_order([l.bounds for l in lines])
+    else:
+        order = psegutils.reading_order([l.bounds for l in lines], nocolumns=True)
     lsort = psegutils.topsort(order)
 
     # renumber the labels so that they conform to the specs