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.

Enabling Checking

The most important API function in controlling the checking subsystem is the IG_REC_spelling_is_enabled_set function. This function is used to enable or disable the running of the checking subsystem.

If it is enabled (default=enabled), the correction of non-compliant words can be enabled or disabled. For this, the IG_REC_correction_is_enabled_set()/IG_REC_spelling_language_set() function is used. If correction is disabled, non-compliant and suspicious words are flagged, but no auto-correction is done. When enabled, all these unchanged words are flagged, while some characters may be changed and are marked as changed. Correction is the default, so the application needs to call this function only when it wants to explicitly disable the word correction feature.

The remaining checking-related API functions are specific to the particular checking system.