Algorithm improvement begins with good test procedures. My early test procedures relied on fairly small buffers of mostly common data. I used these to test best-case and edge-case conditions. However, the data was not real. Once I included about 580K of raw image data to compress, I was able to better […]

My new compression API and new, enhanced test procedure have revealed quite a bit about the state of my compression code. Adaptive arithmetic encoding is not working at all, which is a bit of a downer because I was only just able to grasp the theory at the time I wrote it a couple […]

Looking back at old code, particularly code that was written as part of a learning process, always inspires a sense of “What the hell was I thinking?”. I knew that my initial “design by convention” API had holes in the logic, but I didn’t know that the algorithms themselves had bugs in them. […]

Since, I was in the neighborhood, that neighborhood being my Compression library, I decided to redesign the interface. The code comes from some Java code that I’d written quite a few years ago as a way of learning Java and building a Java Imaging library. As it turns out, I hate programming in […]

Sometimes writing/developing software is like picking a loose thread on a sweater. At first you see it, it bothers you, then you try to fix it, usually by just yanking on it. This just makes it worse and turns into an even bigger job.
The GIF image format relies on the ex-patented LZW compression […]

The Windows port of my code is completed. Of course, porting meant that certain build procedures and some code will now have to be backported to Linux, but I can wait for that. In the meantime, I built my JPEG and GIF plug-in stubs and rebuilt and tested my PNM plug-in.
Now, it’s back […]

In spite of my current workload and the holiday season, I was finally able to get most of my Imaging library ported to Windows XP. I was able to read and write a BMP file using a plug-in. I tried to use a TIFF plug-in, but it failed in a strange way. […]