14 Replies Latest reply on Jun 3, 2015 12:06 PM by TSGal

    Inconsistent Code 93 scanning of low-resolution images

    jbante

      Summary

      Inconsistent Code 93 scanning of low-resolution images

      Product

      FileMaker Go

      Version

      13.0.2

      Operating system version

      iOS 7.0.4 (11B554a)

      Description of the issue

      FileMaker Go is sometimes unable to scan a Code 93 barcode from a low resolution image. Higher resolution images with identical bar patterns scan successfully. I suspected that the low resolution might be the problem, but other images with the same one-pixel-per-module resolution also scanned successfully.

      Steps to reproduce the problem

      Render a Code 93 barcode at a resolution of 1 pixel per module and insert it into a container field. Attempt to scan the barcode using the Insert from Device script step, scanning directly from the container field. (This does not fail with all symbols.) Render the exact same bar pattern at a higher resolution, and insert it into a container field. Scan the larger image using the Insert from Device script step.

      Expected result

      Scanning the lower resolution image should decode the Code 93 barcode every time.

      Actual result

      The lower resolution image is not always successfully scanned. In these cases, the target field of the Insert from Device script step is left blank. The Insert from Device script step results in error 418 ("Internal failure in INSERT operation into a field").

      Exact text of any error message(s) that appear

      If error capture is off when the Insert from Device script step is run, a dialog titled "Error" opens with the message "Insert from Device failed." and one button option labeled "OK".

      Configuration information

      Not all low resolution Code 93 barcodes have trouble being decoded. The larger barcodes that scan successfully have width dimensions that are exact integer-multiple widths of the smaller codes with identical bar patterns. I made a file demonstrating barcodes that do and do not demonstrate the bug: https://www.dropbox.com/s/43edn2kibhc2cb2/BugSampleCode93.fmp12.zip

      Workaround

      Rendering a larger version of the barcode reliably makes it scannable.