How the PatternMatch_Identify action works

When Datacap starts the PatternMatch_Identify action, it gathers all of the anchor objects from all of the fingerprints, then looks for a match on the current page.

The Datacap system does not search the entire page. Instead, it searches a region 200 pixels greater in each direction than the zone defined for the anchor object. If it finds a match that meets the required confidence level, it sets the page type and computes the offset values.

Tip: You can change the size of the search region by setting the anchor field's METRIC variable. For example, METRIC=200,300 increases the width by 200 pixels in each direction and the height by 300 pixels in each direction.

The following RRS log entries, which are taken from pageid_rrs.log, illustrate how PatternMatch_Identify works.

Created PatternMatch Object
Aquired PM lock
Loading Patterns...
   Vendor_Logo : Pattern Found for '565' with zone (171,194,563,302)
   Vendor_Logo : Pattern Found for '566' with zone (678,191,1044,296)   1 
   Vendor_Logo : Pattern Found for '567' with zone (1187,206,1524,286) 
Opening 'provider=microsoft.jet.oledb.4.0;data 
source=C:\Datacap\TravelDocs\TravelDocsFingerprint.mdb;persist security info=false'
Fingerprint/Rules Database connection established.
Search Image: 'c:\datacap\traveldocs\batches\20110018.013\tm000001.tif'
Matching ID# 566 Conf: 10. 2  X: 240 Y: 271. Search Area: 478,0,1244,496  3  Field 
ReqConf:8 --> TRUE
   Calculated offset is: (40,80) 4 
Releasing PM lock

RRS log entry	Description
1	The `PatternMatch_Identify` action finds a `Vendor_Logo` pattern that is defined in each of three fingerprints: 565, 566, and 567.
2	It matches the pattern on fingerprint 566 to a region on the current page with a confidence level of 10 (the highest possible).
3	The search area for fingerprint 566 is 200 pixels greater in each direction than the zone defined for the anchor object.
4	It calculates the x and y offsets between the position of the anchor object and the position of the matching pattern on the page.