Q: We are using jPDFOptimizer and converting images in PDF document to JPEG2000 format. Could you please explain why we sometimes see the following error in the log? When this happens, the outptut optimized PDF is still fine.

java.lang.IllegalArgumentException: Overall target bitrate too low, given the current bit stream header overhead
at jj2000.j2k.entropy.encoder.EBCOTRateAllocator.initialize(EBCOTRateAllocator.java:564)
at com.sun.media.imageioimpl.plugins.jpeg2000.J2KImageWriter.write(J2KImageWriter.java:370)

A: Sometimes the J2K compressor throws an exception with the message:

“Overall target bitrate too low, given the current bit stream header overhead”

jPDFOptimizer will catch this exception and then compress the image to JPEG200 using a higher bit rate. So even though you might see this exception in the log, the output file should be fine.