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 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.