Hi,

I guess that your issue happens in some specific case and therefore it can be 
hard to catch by others. It would be excellent if you could prepere a 
re-producible test set with an image and advice about how to make a layer from 
it, and WMS requests to test with.


-Jukka Rahkonen-

________________________________
Paul Madden wrote:
Re: [Geoserver-users] Dimensions "are too large" when requesting reprojected 
raster via WMS


I am still surprised that simply changing the size of the requested image leads 
to an error, but I have given up -- for now -- on trying to understand exactly 
why. As long as I avoid requesting certain bbox values, it seems that I can 
avoid errors, and that will have to be good enough for now. I will try 
investigating the developer-level logs if I run into the issue again.


For what it's worth, I can open one of my GeoTIFF files in QGIS, view it in the 
native EPSG:6931 projection (which I have to define as a Custom CRS, as it is 
apparently unknown to QGIS, and also reproject it to EPSG:3413 and even mix 
with with layers requested from a remote GeoServer whose native projection is 
EPSG:3413.

I have a new problem, with ImageMosaic, but will start a new thread to ask 
about that if I cannot find a solution in the list archive.

thanks,
paul

________________________________
From: Rahkonen Jukka (MML) <jukka.rahko...@maanmittauslaitos.fi>
Sent: Tuesday, January 24, 2017 02:07
To: Paul Madden; geoserver-users@lists.sourceforge.net
Subject: Re: [Geoserver-users] Dimensions "are too large" when requesting 
reprojected raster via WMS


Hi,


Sorry for reading too many zeros from your GetMap requests.

For why EPSG:6931 GetMap works with extra large BBOX I believe it is because 
EPSG:6931 is the native projection of your data. There is no need to reproject 
the bounding box and map gets filled with empty pixels where there are no image 
data. If the bounding box must be re-projected first then unreasonable big 
coordinate values can lead to an error because the transformation formula may 
not be able to handle it. Sometimes is happens, sometimes not, and it depends 
on the transformation library and source and target SRS.


So, probably I was wrong with my thoughts about too large coordinate values. 
However, what I wrote about BBOX coordinates  which need to be expressed in the 
same units than SRS is right.


I can't say why you get the errror by just increasing height and width. Turn 
the logging level of your Geoserver into Geotools developer and have a look 
what you get into log. Have you tried if your map works with QGIS in both 
projections?


-Jukka Rahkonen-




________________________________
Lähettäjä: Paul Madden <madd...@colorado.edu>
Lähetetty: 24. tammikuuta 2017 7:52
Vastaanottaja: Rahkonen Jukka (MML); geoserver-users@lists.sourceforge.net
Aihe: Re: [Geoserver-users] Dimensions "are too large" when requesting 
reprojected raster via WMS


Hi Jukka,


Many thanks for your response, it was helpful and gave me more to think about.


> 30, 50, or 70 million meters is much more than 2.3 million meters and 382 
> thousand meters which are valid for eastings and northings in EPSG:3413, 
> respectively.


My bounds were actually 3, 5 and 7 million meters (hopefully I did not make a 
typo in my previous post) rather than 30, 50 and 70 -- though this does not 
contradict your point that these values lie outside valid EPSG:3413 
coordinates. However, I notice that my OpenLayers application regularly 
generates bbox values outside EPSG:3413's range, which GeoServer seems to have 
no trouble with. In fact, I just tried an EPSG:3413 WMS request with a *70* 
million meter square bbox, against a native-SRS EPSG:3413 layer, and GeoServer 
returned a correct-looking image.


When I try your gdaltransform example with 3, 5 and 7 million meter values, I 
see no more NANs (though I am not sure what to make of the values that are 
returned).

> You say that the EPSG:6931 coordinates are ok.

I am not sure that they are ok (i.e. valid), but GeoServer seems to handle them 
gracefully -- as long as I do not request reprojection. I just tried EPSG:6931 
WMS requests with both 7 and 70 million meter square bboxes, against the native 
EPSG:6931 layer, and GeoServer returned images for both requests.

A colleague told me today that some coordinates, in meters, when interpreted 
with respect to EPSG:6931, cannot be mapped to lat/lon points. So I wonder 
whether it might be the case that, when reprojecting between SRSes, an 
intermediate projection to lat/lon is performed, so that NAN values appear for 
non-reprojectable EPSG:6931 coordinates, aborting the process. But, somehow, 
GeoServer copes with e.g. a 70 million meter square bbox when reprojection is 
NOT requested, perhaps by reducing it to the bounds known/declared to be valid 
for the layer.

Here is another strange (to me) case that I'm still confused about. This 
request returns a correct-looking image:

<https://localhost:8080/geoserver/NSIDC/wms?service=WMS&version=1.1.0&request=GetMap&layers=NSIDC:nsidc_0532_sea_ice_cover&styles=&bbox=-5000000,-5000000,5000000,5000000&width=500&height=500&srs=EPSG:3413&format=image/png>https://localhost:8080/geoserver/NSIDC/wms?service=WMS&version=1.1.0&request=GetMap&layers=NSIDC:nsidc_0532_sea_ice_cover&styles=&bbox=-5000000,-5000000,5000000,5000000&width=500&height=500&srs=EPSG:3413&format=image/png<https://qa.bedims-geoserver-standalone.apps.int.nsidc.org/geoserver/NSIDC/wms?service=WMS&version=1.1.0&request=GetMap&layers=NSIDC:nsidc_0532_sea_ice_cover&styles=&bbox=-5000000,-5000000,5000000,5000000&width=500&height=500&srs=EPSG:3413&format=image/png>

But this request

https://localhost:8080/geoserver/NSIDC/wms?service=WMS&version=1.1.0&request=GetMap&layers=NSIDC:nsidc_0532_sea_ice_cover&styles=&bbox=-5000000,-5000000,5000000,5000000&width=800&height=800&srs=EPSG:3413&format=image/png

returns the same XML "Dimensions (width=59142 height=59142) are too large" 
error mentioned in my previous post. The only difference is the width & height 
of the requested image, not the bbox, or the fact that a reprojection to 
EPSG:3413 is requested from the native EPSG:6931.

I'd like to have a better mental model of what is happening here. Am I simply 
in undefined-behavior territory, by using too-large bbox values, sometimes 
getting lucky and sometimes not? The fact that I can succeed or fail based on 
the image size makes it seem a bit like a resource issue. Also, I'm surprised 
that I can use a too-big bbox when I do not request reprojection, but I cannot 
(or sometimes cannot) when I do request reprojection. The latter is probably 
naiveté on my part.

Again, I would appreciate any insight on this.

paul

________________________________
From: Rahkonen Jukka (MML) <jukka.rahko...@maanmittauslaitos.fi>
Sent: Monday, January 23, 2017 08:46
To: Paul Madden; geoserver-users@lists.sourceforge.net
Subject: Re: [Geoserver-users] Dimensions "are too large" when requesting 
reprojected raster via WMS


Hi,



The BBOX and SRS (which actually shoud be CRC when you use WMS 1.3.0) go hand 
in hand.  If you want to achieve a map from the same area you can’t just change 
the projection but you must use also BBOX that is re-projected to the other 
coordinate system.  WMS clients like QGIS or OpenJUMP do it automatically.



I had a try with a gdaltransform utility http://www.gdal.org/gdaltransform.html 
and tried to convert the lower-left corners of your EPSG:6931 BBOXes into 
EPSG:3413. The result was that two of those (-50000000 -50000000 and -30000000 
-30000000) gives “not a number” which means that conversion is not possible.


gdaltransform -s_srs epsg:6931 -t_srs epsg:3413

-50000000 -50000000

1.#QNAN 1.#QNAN 0

-7000000 -7000000

3.37694958262492e-009 -15208428.8819585 0

-30000000 -30000000

1.#QNAN 1.#QNAN 0



I do not know why transformation fails. You say that the EPSG:6931 coordinates 
are ok.

However, by having a look at projection EPSG:3413 https://epsg.io/3413 it is 
obvious that your hand written bounding boxes do not make sense because the 
coordinates do not fit inside the valid area of that coordinate system:



Projected bounds:

-2353926.81 2345724.36

-382558.89 383896.60



30, 50, or 70 million meters is much more than 2.3 million meters and 382 
thousand meters which are valid for eastings and northings in EPSG:3413, 
respectively.



What you need to do is simple to use EPSG:3413 bounding box with CRS:3413.



-Jukka Rahkonen-

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