Make property checking on palette object a little more robust. JN
Avoid division by 0 on width calc. JN
If image height or width is 0, bail out of sizing routine. JN
If image height or width is 0, bail out of sizing routine. JN
Enhancements to barcodes:
- Added checksum as option (already supported by report lab).
- Switched humanreadable to use int() to make the conversion to attribute, so you can specify humanreadable="0" and it works as expected.
Merge pull request #91 from photojosh/master

Updated barcode rendering with option for checksum, enhanced humanreadable
Merge pull request #87 from trib3/master

Prevent errors when weird images are encountered