For IMAGING-154 I was trying to think in a solution for the existing Debug class. This class was the issue of discussion during a previous 1.0 release vote thread.

Initially I tried simply changing the class a bit, and make it configurable, so that we could keep it - as there is a valid use case for having a class that collects information during the image processing algorithms were applied.

And for me, the next step would naturally be to remove the use of System.out, as the Debug class would now have a PrintStream that could be System.out or something else.

That’s when I realized in the current version of Apache Commons Imaging (née Sanselan) uses System.out when debugging, but also when it wants to enable a “verbose” mode in some classes.

I am using this post to collect a few cases, and check what other image processing images are doing with regards to logging.

Library Logger
Java ImageIO No logging (exceptions only)
im4java No logging (exceptions only)
opencv JNI No logging (exceptions only)
GeoSolutions ImageIO-Ext java.util.logging
Catalano java.util.logging
Apache PDFBox JBIG2 Custom Logger
ImageJ2 SciJava Logger
Fiji SLF4J + logback
OpenJPEG Custom Logger
imgscalar System.out
Apache Commons Imaging System.out
Sanselan System.out
Marvin System.out
Processing System.out