OEM_TESSERACT_ONLY, // Run Tesseract only - fastest 很快
OEM_CUBE_ONLY, // Run Cube only - better accuracy, but slower 准确但是慢
OEM_TESSERACT_CUBE_COMBINED, // Run both and combine results - best accuracy 准确
OEM_DEFAULT // Specify this mode when calling init_*(),
// to indicate that any of the above modes
// should be automatically inferred from the
// variables in the language-specific config,
// command-line configs, or if not specified
// in any of the above should be set to the
// default OEM_TESSERACT_ONLY.
};