[Geoserver-users] Raster image quality problem

GeoServer GeoServer User
1

Andrea,

I have tried on two different systems with the same pixelated results:

1) Linux (CentOS), Java 1.6 (with JAI), GS 1.6 b1, Tomcat 5.5
2) Win2kPro, Java 1.6 (no JAI), GS 1.6 b3 and a recent nightly, Jetty 6.0.2

WMS rendering is the same in both cases:
  SVG - Batik and Antialias
  Interpolation - Bilinear

The settings for the coverage are also the same:
  SRS: EPSG:2913
  Envelope: 7650628,672226,7651303,672896

Is there any other information that might be helpful?

Thanks,
Nathan

P.S. This thread originally started earlier and wandered offline. Sorry.
http://www.nabble.com/Raster-image-quality-problem-tf4576902.html

-----Original Message-----
From: Andrea Aime [mailto:aaime@anonymised.com]
Sent: Thursday, October 25, 2007 12:51 AM
To: Banks, Nathan
Cc: Chris Holmes
Subject: Re: Raster image quality problem

Banks, Nathan ha scritto:

I've installed the latest nightly but am still seeing the same
problems. JAI is not installed separately ( I thought it was included
as part of Geoserver - do I need to do something to specifically use
it?)

JAI is made up of a pure java part and a native part. It may work
with the pure java part only, but in this case it's not set for
optimal performance (for example, png encoding is slower).

Theoretically it should be only a performance thing, but in fact
on my PC I do have the native part installed as well and it's the
only difference I can think about.

In fact I also tried out running GeoServer with a jdk that does
not have the native JAI installed and I get the same (good) results
so I'm a little out of luck here...

What operating system, jdk and web container are you running onto?
Also, can we keep these mails public? Other users may have an insight,
or other developers could.

Ah, finally, to install native jai we should have a guide here:
http://docs.codehaus.org/display/GEOSDOC/Dealing+with+native+JAI
(that is, I hope the guide is still there because codehaus has been
mostly unreachable for me during the last two days).

Cheers
Andrea

2

Banks, Nathan ha scritto:

Andrea,

I have tried on two different systems with the same pixelated results:

1) Linux (CentOS), Java 1.6 (with JAI), GS 1.6 b1, Tomcat 5.5
2) Win2kPro, Java 1.6 (no JAI), GS 1.6 b3 and a recent nightly, Jetty 6.0.2

WMS rendering is the same in both cases:
  SVG - Batik and Antialias
  Interpolation - Bilinear

The settings for the coverage are also the same:
  SRS: EPSG:2913
  Envelope: 7650628,672226,7651303,672896

Is there any other information that might be helpful?

I can't seem to reproduce what you're seeing. I've set up the
tile you sent me here for you to look at:
http://geo.openplans.org:8080/geoserver/www/hires.htm
Is this one ok for you? It seems ok to me.

If so, I'm starting to suspect the images you see are stretched
for some client side effect, such as:
* putting the image in an img tag whose size is bigger than the
   image itsel (client side stretching)
* wms requests that do create a stretch effect because of a
   mismatch between the aspect ratio of the tile and the one
   of the bounding box.

Also, what .prj file have you associated to the images?
Attached you can find the one I've used.

Nathan, is there any way for me to access (read only) your
server and see where the problem lies?
Cheers
Andrea

1s1e11du-ll-ll.prj (926 Bytes)

3

Success! My *.prj file was messed up. When I replaced it with yours the rasters started rendering beautifully. I can't believe it was that simple.

Thanks again for you assistance with this.

-Nathan

-----Original Message-----
From: Andrea Aime [mailto:aaime@anonymised.com]
Sent: Friday, October 26, 2007 1:18 AM
To: Banks, Nathan
Cc: Geoserver-Users@anonymised.com Sourceforge. Net (E-mail); Chris Holmes
Subject: Re: Raster image quality problem

Banks, Nathan ha scritto:

Andrea,

I have tried on two different systems with the same pixelated results:

1) Linux (CentOS), Java 1.6 (with JAI), GS 1.6 b1, Tomcat 5.5
2) Win2kPro, Java 1.6 (no JAI), GS 1.6 b3 and a recent nightly, Jetty 6.0.2

WMS rendering is the same in both cases:
  SVG - Batik and Antialias
  Interpolation - Bilinear

The settings for the coverage are also the same:
  SRS: EPSG:2913
  Envelope: 7650628,672226,7651303,672896

Is there any other information that might be helpful?

I can't seem to reproduce what you're seeing. I've set up the
tile you sent me here for you to look at:
http://geo.openplans.org:8080/geoserver/www/hires.htm
Is this one ok for you? It seems ok to me.

If so, I'm starting to suspect the images you see are stretched
for some client side effect, such as:
* putting the image in an img tag whose size is bigger than the
   image itsel (client side stretching)
* wms requests that do create a stretch effect because of a
   mismatch between the aspect ratio of the tile and the one
   of the bounding box.

Also, what .prj file have you associated to the images?
Attached you can find the one I've used.

Nathan, is there any way for me to access (read only) your
server and see where the problem lies?
Cheers
Andrea

4

Banks, Nathan ha scritto:

Success! My *.prj file was messed up. When I replaced it with yours the rasters started rendering beautifully. I can't believe it was that simple.

Thanks again for you assistance with this.

Yeah! :slight_smile:
Cheers
Andrea