The checking subsystem is mainly used to achieve better accuracy in the recognized output text and/or to make proofing more effective. Its services are closely integrated into the recognition process, they are activated internally either during the recognition (by some recognition modules) or immediately after the recognition process. That is why all the checking related settings have to be set BEFORE calling the IG_REC_image_recognize() function.

The checking subsystem consists of the following three independent parts:

• Spell Checking: using language-specific dictionary elements
• UD Checking: checking against the User dictionary (with words, strings or patterns)
• User-Written Checking: using user-written callback functions

Any combination of these parts is possible during the recognition process as steps in determining the acceptability of words. Note that the use of these checking methods can still be enabled or disabled separately at zone level.