Code Detection
If more than one working code is detected for a given target then an error should be generated. That is, if three codes are present but only one of them is working (the other two lead to 404 errors) then the working code can be used. But if two codes are working then an error should be generated. This is partly to support Private labels since each Private label can only be read in a specific OpenQualia compatible software; where allowed a Public label is a better solution when broad support is desired.
Note this would only be possible because the standard allows additional parameters beyond the three required TargetID, TargetType, Manufacturer fields which should always be unique to a given physical target. However, using this allowance to label a target with more than one OQ Label is not supported. To support the archiving of older measurements please see “Older Measurement File Archive Retrieval” in the Hosting section of this document.
The machine readable code should be physically placed either:
- Entirely inside edges of the target (e.g. stuck to the front of the target in an otherwise unused area of the target)
OR
- Entirely outside the physical target edges, but close to the target. The entire target should be within a margin of the target defined by 10% of the short side of the target.
This allows the code to be placed on the target, or on a backing paper or mount immediately next to it, while decreasing the chance a target and a code are incorrectly associated. Requiring that the label be entirely inside or entirely outside the target edges – explicitly not allowing the label to overlap or cover the edge of the target – prevents confusion in target detection that is based on the outer edges of the target.
