Multiple anchor objects

To improve pattern matching accuracy, you can specify multiple anchor objects. For example, by defining anchor objects at the upper left and lower right of the page, you can improve the resulting registration.

PatternMatch_Identify does only a simple averaging of the offsets. The pat_registerZones action can do interpolate registration, where field positions are adjusted based on their proximity to each of the anchor objects.

In the following example, IBM® Datacap Taskmaster Capture located an anchor object at the upper left and the lower right of the page. Then, it calculated an offset value for each anchor. It averaged these values to determine the offset required to bring the page image into best alignment. It wrote these values to the Image_Offset variable of the page.

Matching ID# 570 Conf: 10. X: 280 Y: 274. Search Area: 0,0,564,513 Field ReqConf:8 --> TRUE
   Calculated offset is: (100,100)      <-- Offset for first anchor object (top left)
Matching ID# 570 Conf: 10. X: 301 Y: 262. Search Area: 1158,1640,1700,2162 Field ReqConf:8 --> TRUE
   Calculated offset is: (101,62)       <-- Offset for second anchor object (bottom right)

<P id="TM000018">
   <V n="TYPE">Test</V>
   <V n="STATUS">49</V>
   <V n="IMAGEFILE">tm000018.tif</V>
   <V n="ScanSrcPath">c:\datacap\traveldocs\images\refstopbottom.tif</V>
   <V n="RecogStatus">0</V>
   <V n="LC_Confidence">8.571231E-02</V>
   <V n="LC_Image_Offset">-16,0</V>
   <V n="LC_TemplateID">562</V>
   <V n="Fingerprint Created">No</V>
   <V n="Confidence">8.571231E-02</V>
   <V n="TemplateID">570</V>
   <V n="PatternConfidence">10</V>
   <V n="Image_Offset">-100,-81</V>   <-- Average required offset
   <V n="DATAFILE">tm000018.xml</V>
</P>

In addition to storing the page image offset, PatternMatch_Identify also creates a page data file. It also stores the zone offset for each anchor in the Zone_Offset variable of the field.

<V n="Zone_Offset">100,100</V>   <-- Offset for first anchor