README for libdmtx version 0.5.2 - September 4, 2008

A minor release in name only, libdmtx 0.5.2 delivers several
performance enhancements, bug fixes, and general improvements
over previous versions. We still have a few enhancements that
haven't made it in yet, which is why this is a minor release, but
most users will already see big performance gains by ugrading to
0.5.2. Depending on the images being scanned, but it's not
uncommon to see a 500x (or better) speedup over 0.5.1 runtimes
when proper tuning parameters are used.

For users of pydmtx (the libdmtx Python wrapper), Jonathan Lung
has also written a new decode2() function which is showing 15x
faster decode times than the original pydmtx decode function.

The performance tuning effort has been a good learning
experience, and has resulted in plans for more significant
changes down the road that will enable even faster performance
and improved scanning of mixed-quality images. The goal is to
deliver these changes in small chunks to minimize regressions
and avoid long release cycles.

Other notable changes in 0.5.2 include:

Performance Improvements
  * New dynamic image shrinking feature (pixel skipping)
  * New squareness deviation feature
  * Simplified Hough transform for locating first edge
  * Several other internal performance enhancements

General Improvements
  * Encoding support for 144x144 barcodes (largest possible)
  * Changed internal pixel storage to use top-left origin
  * Various improvements when building for OS X and FreeBSD
  * Added new experimental PHP wrapper code (Thanks Christian!)
  * Several bugs fixed (see ChangeLog)

As always, please let us know if you find any bugs or have
trouble installing the software. Messages should be sent to the
mailing list: