bad recognition of particular file

[jasondbiggs]

Using the image below, molvec version 0.9.8 is recognizing it as ethane (version 0.9.6 was finding propane). Is there something wrong with this PNG? Is there some kind of preprocessing that might improve the recognition?

$ java -jar $molvec -f '/Users/jasonb/molvec_issue.png'

  Molvec0104152114022D

  2  1  0  0  0  0  0  0  0  0999 V2000
    0.5000   -0.0000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
   -0.5000   -0.0000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
  1  2  1  0
M  END