Monday, April 4, 2016

Resolution of historic photographs in examples, part 2

In my previous post I explored one of the smallest and oldest glass plate negatives in our archive to show it has resolution at least 2000PPI (or 40 line pairs per millimeter, lp/mm) which correspond to 80-90 megapixel photograph. This noticeably exceeds the published estimates of resolution of historic film.

This time I take a detailed look on one of largest negatives in our collection - a monster plate 30x40cm. The photograph was taken by my great-great-grandfather and/or great-grandfather in 1903 documenting the construction of the first electric railway in the Austro-Hungarian empire by František Křižík ("Czech Edison"). This unique event was recorded in a series of photographs prepared by the best technology available to a photographer of Czech countryside. While the glass plate I am going to speak about may be considered one of the more boring in the series it shows some extra-ordinary detail.

Sunday, March 27, 2016

Resolution of historic photographs in examples, part 1

As everyone knows, historic photographs are full of lovely and important details. Well, at least everyone who had paid enough attention to explore an original or had chance to see a quality scan. In 19th century photographs was not enlarged and the prints matched the size of negatives. Even small CDVs was intended to be viewed with care under a magnifying glass.

Friday, March 25, 2016

Lost notebook

My lovely notebook Lenovo X240 Serial Number PF0088FT was lost in Prague, Mar 24 2016. If you find it and contact me at, I would be extremely grateful.

UPDATE: I got the notebook back from police this week :)

Friday, March 18, 2016

Building libreoffice with GCC 6 and LTO

New GCC is just around the corner. For me, as a GCC developer, this means a period of bugfixing, benchmarking and fine-tuning. Two years ago I wrote about my experiment  of building libreoffice with link time optimization (LTO). At that time LTO just got into shape of being able to build such large applications. Since that I am keeping my eye on this and try to be sure LTO keeps improving. I did not have time to publish any tests for GCC 5. Here is update for current trunk of GCC 6 compared to GCC 4.9.0, GCC 5.3, LLVM 3.5 and trunk.