Hi List,
One thing I'm noticing with PHOTOMETRIC=YCBCR - I'm losing a lot of
sharpness.
In fact, a 50% without YCBCR looks better than a 85% that also has YCBCR
enabled.
This is very noticeable at the native resolution, but once you're about
double it or further, it's effectively invisible.
On the other hand, the YCBCR is about 25% the size of
a equivalently compressed JPEG. I guess I'm going to have to choose which
way to go.
============
I've also been testing a lot of other variables and for some reason DEFLATE
compression seems to make the file *larger* in all circumstances. It
doesn't matter what the Z level is (even 9), or "predictor", in all
instances the resultant file is larger than an uncompressed version. That's
with four band data.
Anyone know why?
Cheers,
Jonathan
On 12 November 2013 14:24, Jonathan Moules <
jonathanmou...@warwickshire.gov.uk> wrote:
> HI All,
> Many thanks for the all the responses. Interesting discussion; I've learnt
> a lot.
>
> I think my next step is to do some testing; I've not tried the four band -
> RGBI imagery yet. When I do I'll post back here with whatever seems to work
> best.
>
> Cheers,
> Jonathan
>
>
> On 12 November 2013 13:45, Even Rouault <even.roua...@mines-paris.org>wrote:
>
>> Selon Andrea Aime <andrea.a...@geo-solutions.it>:
>>
>> > On Tue, Nov 12, 2013 at 12:45 PM, Simone Giannecchini <
>> > simone.giannecch...@geo-solutions.it> wrote:
>> >
>> > > >
>> > > > Will the PHOTOMETRIC= YCBCR work with a four band RGBI?
>> > > >
>> > >
>> > > It should not.
>> > >
>> >
>> > Actually... JPEG itself is not defined on 4 bands images as far as I
>> know?
>> > Maybe GDAL is dropping the 4th band during the JPEG compression?
>>
>> The YCbCR JPEG profile of TIFF is indeed limited to 3 bands. So if you
>> pass a 4
>> band image, gdal_translate should refuse to process it.
>> You can JPEG compress a 4 band image, but it will use a JPEG codestream
>> for each
>> band independantly, so the resulting size will be bigger.
>> A possible option would be to generate 2 GeoTIFFs for each input file :
>> one
>> YCbCR JPEG compressed with the RGB components, and one JPEG compressed
>> with the
>> I component. But that might complicate the overall workflow.
>>
>> Even
>>
>> >
>> > Cheers
>> > Andrea
>> >
>> > --
>> > ==
>> > Our support, Your Success! Visit http://opensdi.geo-solutions.it for
>> more
>> > information.
>> > ==
>> >
>> > Ing. Andrea Aime
>> > @geowolf
>> > Technical Lead
>> >
>> > GeoSolutions S.A.S.
>> > Via Poggio alle Viti 1187
>> > 55054 Massarosa (LU)
>> > Italy
>> > phone: +39 0584 962313
>> > fax: +39 0584 1660272
>> > mob: +39 339 8844549
>> >
>> > http://www.geo-solutions.it
>> > http://twitter.com/geosolutions_it
>> >
>> > -------------------------------------------------------
>> >
>>
>>
>>
>>
>> ------------------------------------------------------------------------------
>> November Webinars for C, C++, Fortran Developers
>> Accelerate application performance with scalable programming models.
>> Explore
>> techniques for threading, error checking, porting, and tuning. Get the
>> most
>> from the latest Intel processors and coprocessors. See abstracts and
>> register
>>
>> http://pubads.g.doubleclick.net/gampad/clk?id=60136231&iu=/4140/ostg.clktrk
>> _______________________________________________
>> Geoserver-users mailing list
>> Geoserver-users@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/geoserver-users
>>
>
>
--
This transmission is intended for the named addressee(s) only and may
contain sensitive or protectively marked material up to RESTRICTED and
should be handled accordingly. Unless you are the named addressee (or
authorised to receive it for the addressee) you may not copy or use it, or
disclose it to anyone else. If you have received this transmission in error
please notify the sender immediately. All email traffic sent to or from us,
including without limitation all GCSX traffic, may be subject to recording
and/or monitoring in accordance with relevant legislation.
------------------------------------------------------------------------------
Shape the Mobile Experience: Free Subscription
Software experts and developers: Be at the forefront of tech innovation.
Intel(R) Software Adrenaline delivers strategic insight and game-changing
conversations that shape the rapidly evolving mobile landscape. Sign up now.
http://pubads.g.doubleclick.net/gampad/clk?id=63431311&iu=/4140/ostg.clktrk
_______________________________________________
Geoserver-users mailing list
Geoserver-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/geoserver-users
