Boost logo

Boost :

Subject: Re: [boost] GIL io_new review
From: Mateusz Loskot (mateusz_at_[hidden])
Date: 2010-12-13 12:53:24

On 10/12/10 19:27, Domagoj Saric wrote:
> "Mateusz Loskot" <mateusz_at_[hidden]> wrote in message
>>>> 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:

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 (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_at_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
Note, 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
but I'm missing some details about how to configure and build it.
Can I find it anywhere?

Best regards,

Mateusz Loskot,
Charter Member of OSGeo,
Member of ACCU,

Boost list run by bdawes at, gregod at, cpdaniel at, john at