IndexError: narray: index out of range (While working with Ocropus)

[Saad Bin Ahmed]

I am working with ocropus for the purpose to binarize and segments the unsegmented images. I use command to binarize the image files by ocropus as

ocropus-binarize -o book /home/images/*.tif

By using the above mentioned command it worked fine for few images but after sometime it prompts an error message as shown below,

File "/usr/local/bin/ocropus-binarize", line 151, in <module>
   result = pool.map(process1, jobs)
File "/usr/lib/python2.7/multiprocessing/pool.py"
   return self.map_async(func, iterable, chunksize).get()
File "/usr/lib/python2.7/multiprocessing/pool.py", line 517, in get
   raise self._value
IndexError: narray: index out of range

Any help regarding the matter would be highly appreciative.