Dear Maintainer,

   * What led up to the situation?
Trying to use a USB sheet feed scanner while a network enabled scanner is
visible on wlan.
   * What exactly did you do (or not do) that was effective (or
     ineffective)?
unplugging the networked scanner
   * What was the outcome of this action?
the bug went away
   * What outcome did you expect instead?
I would expect that scanimage does not allow HTML on standard out when a PNG is
expected.  Errant HTML should be dropped and stderr should communicate the
unexpected result.  If still possible to process the image the image should
process.