A barcode's distortion is typically not able to be identified by the human eye unless the image is significantly magnified. Once magnified, it's often easy to see merged or smeared bars of the barcode, significant noise present, or parts of the barcode missing.
Other distortions, however, can only be parsed by specialized tools that may require extensive and intensive analyses.
Avoid barcode images from the Web. Though they look good on a Web page, they usually fail the above magnification test.
If you need to test your application with good-quality images, use either the test images available from Inlite (TODO LINK) or use one of the online barcode generators.
There are two fundamentally different barcode-based applications: User-operated barcode readers and independent barcode readers. Their fundamental difference is in the former's continuous scanning process vs. the latter's single static scan.
A user-operated barcode reader is a device that gives you an "immediate" barcode reading. Typical examples of such devices are:
- Hend-held or counter-mounted scanners one can see at supermarket checkouts
- Mobile phones with built-in barcode scanning applications
In such devices, the scanning element is tightly integrated with the built-in barcode reader software. Each time user scans the barcode, the reader acquires multiple images or data samples until the barcode is read. Moving the scanner against a scanned object creates an image with different distortions that allow for the eventual selection of a sufficiently good quality image.
The process of re-scanning is done without the user typically being aware of this.
In an independent barcode reader, to which group the Inlite Barcode Reader belongs, the process of scanning and reading software is decoupled. Consequently, the reader has only one version of the scanned image.
Such readers often operate in unattended back-end environments, where scanning occurs significantly before reading. The consequence of failure to read the barcode is higher operational costs.
Another use is an operator-driven application, where an operator sits at the workstation with the attached scanner. Failure to read the barcode can be recognized in real-time, but it still needs action by the operator to reinsert failed page.
Since such a reader deals with only one version of the scanned image, some distortions introduced in the image generation process might create a completely unreadable barcode.