On 10/12/10 19:27, Domagoj Saric wrote:
"Mateusz Loskot" <mateusz@loskot.net> wrote in message news:4D00FF4B.7070901@loskot.net...
4. Cutting TIFF to PNG involves compression. If we are interested in raster access, RIO, I/O speed, perhaps we could stick to TIFF as output format as well. What you think?
That depends on what exactly are we trying to test here, the C++ wrappers (e.g. io_new vs io2) and/or the backends (e.g. LibTIFF vs WIC) and/or something third...
Actually, that was part of my initial question.
Hi, sorry for the delay...
Sorry for delay too Here is the tiling benchmark for GDAL: https://github.com/mloskot/workshop/tree/master/benchmarking/tiling/gdal The gdal_image_tiles_test.cpp + Makefile for those who would like to run it in their environments. The results.txt file includes timing + tiles number + total size of tiles for PNG and JPEG output. Shortly, my results on Intel P8600 + 4GB RAM with Linux (amd64) PNG: 11:30 - 11:50 min JPG: 2:10 - 2:30 min RAM usage observed for both is less than 5MB.
This code http://codepad.org/eGMixUK1 (io2 using the WIC backend, unfortunately large TIFF support was added only to the latest WIC available on Windows 7 so the same code will not work on WinXP) opens the input TIFF and hacks it up into separate tile files. With an Intel i5@4.2 GHz with 4 GB RAM I got the following results:
Looks like run on ~1.5x faster machine, considering clock of single CPU.
200x200 PNG tiles ~ 65 seconds 512x512 PNG tiles ~ 69 seconds
What compression level did you use? See results.txt for my details.
512x512 TIFF tiles ~ 27 seconds
I assume it's no compression, right? I haven't tried TIFF.
RAM usage was below 5 MB the whole time (after working around an apparent leak in WIC that otherwise cause the RAM usage to crawl up to ~15 MB)
Similar to the GDAL run.
and the binary is about 45kB...
The size of binaries in GDAL test is: 26K test program + 11M libgdal.so Note, libgdal.so is built with support of more than 120 dataset formats.
... I guess these tasks are no longer so hard for modern hardware as my work desktop churns them out pretty fast...
Indeed, your results are very impressive. I'm going to run your benchmark and submit my results here https://github.com/mloskot/workshop/tree/master/benchmarking/tiling/gil but I'm missing some details about how to configure and build it. Can I find it anywhere? Best regards, -- Mateusz Loskot, http://mateusz.loskot.net Charter Member of OSGeo, http://osgeo.org Member of ACCU, http://accu.org