Support image/png output with WCS GetCoverage requests

[James Passmore]

image/png output is supported for WCPS requests but not currently for WCS GetCoverage requests.

For example:

​http://earthserver.bgs.ac.uk/rasdaman/ows?service=WCS&Request=GetCoverage&version=2.0.1&CoverageId=mean_summer_airtemp&format=image/png&

Gives the following error:

<ows:ExceptionReport version="2.0.0" xsd:schemaLocation="http://www.opengis.net/ows/2.0 http://schemas.opengis.net/ows/2.0/owsExceptionReport.xsd" xmlns:ows="http://www.opengis.net/ows/2.0" xmlns:xsd="http://www.w3.org/2001/XMLSchema-instance" xmlns:xlink="http://www.w3.org/1999/xlink">
<ows:Exception exceptionCode="NoApplicableCode">
<ows:ExceptionText>
No appropriate format extension was found that can handle the request for format : image/png
</ows:ExceptionText>
</ows:Exception>
</ows:ExceptionReport>

Can png support be added to Petascope for such requests?

[Bang Pham Huu]

@Alex,
I've submitted a patch today ([PATCH] ticket:876 - Support image/png output with WCS GetCoverage requests ) please have a look and comment before Dimitar can accept.

Thanks,

[Alex Dumitru]

@Bang Patch looks good on my side. However taking into consideration ticket:1039 I think it might be best to integrate all formats in your new class and maybe rename it to something like GeneralFormatExtension?

@Peter Do we want to support all formats that gdal supports or just a limited subset of them? The list is quite big ​http://www.gdal.org/formats_list.html

[Bang Pham Huu]

@Alex: I agree with you, thanks for review. In fact, it starts from ​http://www.rasdaman.org/ticket/669 and at that time it should be make only class to handle request "format extension". I also think it is good that can encode/decode many kinds of format as GDAL can do (but if rasql can do this then there will no problem because Petascope only generate RASQL query).

[Alex Dumitru]

Comments by Peter from the duplicate ticket:

3 issues:
​http://www.opengis.net/spec/png/1.0/ does not exist
comment has bad grammar
insufficient test cases

[Bang Pham Huu]

All of the comments has been fixed and accepted by the earlier patch. I will close this ticket in here.