Image size error reporting

Hi all,
I'm working on the image resizing and specify test right now and I wanted to
ask for opinions. Here are options for how it is implemented:

1) As is, we have a series of if statements testing both height and width
(after we've established that indeed these tags are there). This means:
- if we have a improperly formatted value, it records a test result value
that reflects the improper formatting and a test result that either warns or
fails depending on how the improper value is evaluated numerically
- both width and height at evaluated simultaneously, so we can record the
line number in which the error occurred, but not which value

2) We can choose not to proceed with the tests after it's been established
that there's an improper value. However, if we stop here, if there's another
issue with the properly formatted value, we never report that

3) We can test height and width values separately. If it is determined that
the height or width is improperly formatted, we report that error, but
continue testing the other value.

Also, I'm still not quite sure what we determined about the position
information format for error reporting. Roland, are you working on that?

Thanks!

Cheers,
Laura