diff --git a/pagenum-mass.py b/pagenum-mass.py
index 08895e8..2932df7 100755
--- a/pagenum-mass.py
+++ b/pagenum-mass.py
@@ -20,6 +20,7 @@ _max_page_num_length = None
 _rename_lock = Lock()
 _outdir: str
 _indir: str
+_psm: Optional[int] = None
 
 
 def safe_copyfile(oldname, newname):
@@ -59,7 +60,10 @@ class PagenumWorker(Thread):
         num = None
         for z in _zones:
             cropped = zonecrop(png_file, z)
-            num = img2pagenum(cropped, args.max_page_num_length)
+            i2pn_kw = {}
+            if _psm:
+                i2pn_kw['psm'] = _psm
+            num = img2pagenum(cropped, args.max_page_num_length, **i2pn_kw)
             os.unlink(cropped)
             if num is not None:
                 break
@@ -86,6 +90,7 @@ if __name__ == '__main__':
     parser.add_argument('-p', '--pretend', action='store_true',
                         help="Don't save files but print info to stdout")
     parser.add_argument('--max-page-num-length', type=int, default=3)
+    parser.add_argument('--tesseract-psm', type=int)
     parser.add_argument('-V', '--verbose', action='store_true')
     args = parser.parse_args()
 
@@ -96,6 +101,8 @@ if __name__ == '__main__':
     _max_page_num_length = args.max_page_num_length
     _outdir = args.output_directory
     _indir = args.input_directory
+    if args.tesseract_psm:
+        _psm = args.tesseract_psm
 
     if not os.path.isdir(_indir):
         raise OSError(f'{_indir}: no such directory')
diff --git a/pagenum-probe.py b/pagenum-probe.py
index f38b399..93dc866 100755
--- a/pagenum-probe.py
+++ b/pagenum-probe.py
@@ -1,5 +1,6 @@
 #!/usr/bin/env python3
 import os
+import logging
 
 from argparse import ArgumentParser
 from pagenum.system import ensure_dependencies, desktop_open_image
@@ -26,8 +27,12 @@ if __name__ == '__main__':
     parser.add_argument('--max-page-num-length', type=int, default=3)
     parser.add_argument('--preview', action='store_true',
                         help="open cropped image part in image viewer")
+    parser.add_argument('--verbose', action='store_true')
+    parser.add_argument('--tesseract-psm', type=int)
     args = parser.parse_args()
 
+    logging.basicConfig(level=logging.DEBUG if args.verbose else logging.INFO)
+
     if not os.path.exists(args.input):
         raise OSError(f'{args.input}: no such file')
 
@@ -40,7 +45,11 @@ if __name__ == '__main__':
     # desktop_open_image(png_file)
     if args.preview:
         desktop_open_image(cropped_file)
-    num = img2pagenum(cropped_file, args.max_page_num_length)
+
+    i2pn_kw = {}
+    if args.tesseract_psm:
+        i2pn_kw['psm'] = args.tesseract_psm
+    num = img2pagenum(cropped_file, args.max_page_num_length, **i2pn_kw)
     print('num:', num)
     os.unlink(png_file)
     os.unlink(cropped_file)
diff --git a/pagenum/image.py b/pagenum/image.py
index 6bdf60b..538bc2c 100644
--- a/pagenum/image.py
+++ b/pagenum/image.py
@@ -114,16 +114,18 @@ def zonecrop(png_path, z):
     return filename
 
 
-def img2pagenum(img_file, maxlen):
+def img2pagenum(img_file, maxlen, psm=13):
     try:
         s = pytesseract.image_to_string(img_file,
                                         timeout=10,
                                         lang='eng',
-                                        config='--psm 13 -c tessedit_char_whitelist=0123456789')
+                                        config=f'--psm {psm} -c tessedit_char_whitelist=0123456789')
     except RuntimeError as timeout_error:
         _logger.exception(timeout_error)
         return None
 
+    _logger.debug(f'raw string: {s}')
+
     for r in '_-.,—':
         s = s.replace(r, '')
     s = s.strip()