Hardware manual

Impact Reference Guide Character Contour Match
3-159 Datalogic Automation Inc.
In the tool’s "Barcode Type" list, the four UPC/EAN/JAN types are grouped into one called “UPC/EAN/
JAN”. The GS1-128 barcode is a subset of Code 128 and will decode as Code 128 in the tool’s "Barcode
Type Found" property. The RSS barcode type was renamed to GS1 Databar in 2007. It is called GS1 Databar
(RSS) in the list above.
There are two barcodes generally named “2 of 5.” The more common type is called “Interleaved 2 of 5,” or
sometimes abbreviated as ITF. The other code is named “Industrial 2 of 5,” or it is sometimes referred to as
Code 25. The Barcode tool supports Interleaved 2 of 5 / ITF.
Unsupported Types
The tool cannot read stacked codes, composite codes, or codes where bar heights encode information. Com-
posite codes are linear codes with an adjacent stacked code. The tool also will not support any of the follow-
ing types.
BC412, Code 128 Composite, GS1 Databar Composite, UCP/EAN Composite, PDF417, Pharmacode
(two-track), PLANET code, POSTNET, GS1 Databar Stacked, Industrial 2 of 5, Code 11, Code 25, MSI
Plessey, Intelligent Mail Barcode (OneCode)
The tool does not support the full AIM specification for grading barcodes. The use of multiple scan lines and
“Percent of Scan Lines That Must Pass” property provides a subset of the grading process.
There are two barcodes generally named “2 of 5.” The more common type is called “Interleaved 2 of 5,” or
sometimes abbreviated as ITF. The other code is named “Industrial 2 of 5,” or it is sometimes referred to as
Code 25. The Barcode tool does not support Industrial 2 of 5 / Code 25.
Verify Optional Check Character
This property applies to barcode types Code 39, Code 39 Full ASCII, Interleaved 2 of 5, and Codabar. These
types may include an optional check character at the end of the code. If this property is True, the tool com-
pares the final barcode character to the rest of the output string. The tool fails if the verification operation
fails.
If the property is False, the verification is skipped and the final barcode character is output as a normal data
character. The tool cannot automatically determine if the check character is present, so the default setting is
False. You should only set the property to True if you know that the check character is present.
The check character is always included in the "Output String" property whether or not this property is True.
Character Contour Match
In the Readers Drawer
The Character Contour Match tool measures character defects by comparing the image character to a trained
model. The tool only verifies characters, so the tool must be trained on a good character before it runs. To
allow for single character verification, define a train and search ROI for each character. If a single train ROI
is placed over several characters, all the characters within the ROI are combined and considered a single
character when the tool trains.
The Character Contour Match tool calculates the differences between the library characters and the verified
characters using boundary length measurements which do not depend on the size of individual letters. This
means it is not sensitive to size differences between letters, for example, between the letters ‘i’ and ‘m.’
Also, the Character Contour Match tool knows what the string should be, so it only compares each image
character to trained models of that character.
This tool “understands” symbols defined as multiple characters similar to the OCR tool. For example, if
there is a symbol such as a ‘comma’ defined in the library and you are trying to verify the string “1,000” you