[BUG] -oem option has no effect with tesseract v4

[hamelg]

CCExtractor version: 0.88
tesseract version: 4.1.1
leptonica version: 1.79.0

• Is this a regression (i.e. did it work before)? NO
• What platform did you use? Linux

Video links

https://app.box.com/s/mhu17q37hc4ofprneydfailktp70pi4l

Additional information

I found out the -oem option doesn't work : if tesseract v4 is installed, ccextract force silently oem parameter to 1.

https://github.com/CCExtractor/ccextractor/blob/master/src/lib_ccx/ocr.c#L182

With oem=1, I get bad results.

I fixed that to set tesseract oem with the option -oem passed on cli (ccx_options.ocr_oem) and now with oem=0 the result is near perfect. On my subs, oem=0 gives the best results, oem=1 or 2 are useless.

$ tesseract --help-oem
OCR Engine modes:
  0    Legacy engine only.
  1    Neural nets LSTM engine only.
  2    Legacy + LSTM engines.
  3    Default, based on what is available.

[cfsmp3]

@hamelg this seems trivial do fix, send a PR? :-)