Web Processing Service
3 likes2,730 views
1) The document discusses a presentation on the Web Processing Service (WPS) standard. WPS defines how geospatial processes can be published, described, and executed over the web. 2) WPS version 1.0 specifies operations for getting process descriptions, executing processes, and managing asynchronous executions. WPS version 2.0 adds new operations for managing process executions. 3) Examples show how WPS can be used for simple GIS processes, image processing workflows, and chaining multiple processes together across different servers.
![<wps:Capabilities service="WPS" xml:lang="en-EN" version="1.0.0" updateSequence="1352815432361">!
<ows:ServiceIdentification>!
[...Service information i.e. title, abstract, keywords, etc...]!
</ows:ServiceIdentification>!
<ows:ServiceProvider>!
[...Provider information i.e. name, adress, phone, etc...]!
</ows:ServiceProvider>!
<ows:OperationsMetadata>!
[...URLs to GetCapabilities, DescribeProcess and execute services...]!
</ows:OperationsMetadata>!
<wps:ProcessOfferings>!
<wps:Process wps:processVersion="1.0.0">!
<ows:Identifier>urn:ogc:cstl:wps:otb:classification</ows:Identifier>!
<ows:Title>Classification</ows:Title>!
<ows:Abstract>Performs an image classification</ows:Abstract>!
</wps:Process>!
[...]!
</wps:ProcessOfferings>!
<wps:Languages>!
[...]!
</wps:Languages>!
<wps:WSDL xlink:href=""/>!
</wps:Capabilities>!
GetCapabilities http://mon.serveur.com/wps?service=WPS&request=GetCapabilities](https://image.slidesharecdn.com/2014-140701075531-phpapp01/85/Web-Processing-Service-24-320.jpg)
![<wps:ProcessDescriptions xmlns:gml="http://www.opengis.net/gml" xmlns:xlink="http://www.w3.org/1999/
xlink" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:wps="http://www.opengis.net/wps/1.0.0"
xmlns:ows="http://www.opengis.net/ows/1.1" service="WPS" version="1.0.0" xml:lang="en-EN">!
<ProcessDescription storeSupported="true" statusSupported="true" wps:processVersion="1.0.0">!
<ows:Identifier>urn:ogc:cstl:wps:otb:classification</ows:Identifier>!
<ows:Title>Classification</ows:Title>!
<ows:Abstract>Performs an image classification</ows:Abstract>!
<DataInputs>!
[...Standardized description of ComplexData, LiteralData or BoundingBoxData...]!
</DataInputs>!
<ProcessOutputs>!
[...Standardized description of ComplexOutput, LiteralOutput or BoundingBoxOutput...]!
</ProcessOutputs>!
</ProcessDescription>!
</wps:ProcessDescriptions>!
DescribeProcess http://mon.serveur.com/wps?service=WPS&request=DescribeProcess&identifier=urn:ogc:cstl:wps:otb:classification
storeSupported If set to true, process is launched asynchronously - acknowledgment is immediately sent back by the server and the
process is executed in background. Otherwise, process is launched synchronously - client holds on until the process is
finished and result is sent back (this could lead to timeout if process is too long)](https://image.slidesharecdn.com/2014-140701075531-phpapp01/85/Web-Processing-Service-26-320.jpg)
Web Processing Service
- 1. Jérôme Gasperi Web Processing Service Séminaire Innovation PS Toulouse, France - 1er juillet 2014
- 2. Interoperability What it means, Why it matters Open Geospatial Consortium Web Processing Service What is WPS ? WPS 1.0 WPS 2.0 WPS in action Simple GIS processing Image processing Chaining WPS What's next ?
- 3. Interoperability What it means, why it matters
- 7. We need to standardize !
- 8. format | description | access files metadata services Known and readable ! (ex.. JPG,TIF, HDF, etc.) A structured (e.g. XML) and standardized (e.g. ISO 19115) description OGC Web services W*S
- 9. INTEROPERABILITY format | description | access files metadata services Known and readable ! (ex.. JPG,TIF, HDF, etc.) A structured (e.g. XML) and standardized (e.g. ISO 19115) description OGC Web services W*S
- 10. Simple Complex Requirements not supported Low harmonization Few benefits Too simple Difficult to implement High costs Substantial benefits to few users Too complex The right level of Interoperability ?
- 12. The Open Geospatial Consortium (OGC) is an international organization originated in 1994 which encourage development and implementation of open standards for geospatial content and services, GIS data processing and data sharing.
- 13. 479members on july, 1st 2014
- 16. Web Processing Service What is WPS ?
- 17. WPS is an OGC standard that defines how to publish, describe and execute geospatial processes
- 18. The WPS interface standardizes the way processes and their inputs/ outputs are described, how a client can request the execution of a process, and how the output from a process is handled.
- 19. WPS does not specify the kind of processes that could be implemented as a web service. Instead, it specifies a generic mechanism that can be used to describe and web-enable any sort of geospatial process
- 21. Web Processing Service WPS 1.0 (Current standard)
- 23. GetCapabilities The GetCapabilities operation p r ov i d e s a c c e s s t o g e n e r a l information about a live WPS implementation, and lists the operations and access methods supported by that implementation Publish 1 DescribeProcess The DescribeProcess operation allows WPS clients to request a full of one or more executed by the service. This description includes the parameters and formats and can be used to automatically build a user interface to capture the parameter values to be used to execute a process Describe 2 Execute The Execute operation allows WPS clients to implemented by a server, using the input parameter values provided and returning Inputs can be included directly in the Execute request, or reference accessible Execute 3
- 24. <wps:Capabilities service="WPS" xml:lang="en-EN" version="1.0.0" updateSequence="1352815432361">! <ows:ServiceIdentification>! [...Service information i.e. title, abstract, keywords, etc...]! </ows:ServiceIdentification>! <ows:ServiceProvider>! [...Provider information i.e. name, adress, phone, etc...]! </ows:ServiceProvider>! <ows:OperationsMetadata>! [...URLs to GetCapabilities, DescribeProcess and execute services...]! </ows:OperationsMetadata>! <wps:ProcessOfferings>! <wps:Process wps:processVersion="1.0.0">! <ows:Identifier>urn:ogc:cstl:wps:otb:classification</ows:Identifier>! <ows:Title>Classification</ows:Title>! <ows:Abstract>Performs an image classification</ows:Abstract>! </wps:Process>! [...]! </wps:ProcessOfferings>! <wps:Languages>! [...]! </wps:Languages>! <wps:WSDL xlink:href=""/>! </wps:Capabilities>! GetCapabilities http://mon.serveur.com/wps?service=WPS&request=GetCapabilities
- 25. GetCapabilities The GetCapabilities operation p r ov i d e s a c c e s s t o g e n e r a l information implementation, and operations supported by that implementation Publish 1 DescribeProcess The DescribeProcess operation allows WPS clients to request a full description of one or more processes that can be executed by the service. This description includes the input and output parameters and formats and can be used to automatically build a user interface to capture the parameter values to be used to execute a process Describe 2 Execute The Execute operation allows WPS clients to implemented by a server, using the input parameter values provided and returning Inputs can be included directly in the Execute request, or reference accessible Execute 3
- 26. <wps:ProcessDescriptions xmlns:gml="http://www.opengis.net/gml" xmlns:xlink="http://www.w3.org/1999/ xlink" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:wps="http://www.opengis.net/wps/1.0.0" xmlns:ows="http://www.opengis.net/ows/1.1" service="WPS" version="1.0.0" xml:lang="en-EN">! <ProcessDescription storeSupported="true" statusSupported="true" wps:processVersion="1.0.0">! <ows:Identifier>urn:ogc:cstl:wps:otb:classification</ows:Identifier>! <ows:Title>Classification</ows:Title>! <ows:Abstract>Performs an image classification</ows:Abstract>! <DataInputs>! [...Standardized description of ComplexData, LiteralData or BoundingBoxData...]! </DataInputs>! <ProcessOutputs>! [...Standardized description of ComplexOutput, LiteralOutput or BoundingBoxOutput...]! </ProcessOutputs>! </ProcessDescription>! </wps:ProcessDescriptions>! DescribeProcess http://mon.serveur.com/wps?service=WPS&request=DescribeProcess&identifier=urn:ogc:cstl:wps:otb:classification storeSupported If set to true, process is launched asynchronously - acknowledgment is immediately sent back by the server and the process is executed in background. Otherwise, process is launched synchronously - client holds on until the process is finished and result is sent back (this could lead to timeout if process is too long)
- 27. GetCapabilities The GetCapabilities operation p r ov i d e s a c c e s s t o g e n e r a l information implementation, and operations supported by that implementation Publish 1 DescribeProcess The DescribeProcess operation allows WPS clients to request a full of one or more executed by the service. This description includes the parameters and formats and can be used to automatically build a user interface to capture the parameter values to be used to execute a process Describe 2 Execute The Execute operation allows WPS clients to run a specified process implemented by a server, using the input parameter values provided and returning the output values produced. Inputs can be included directly in the Execute request, or reference web accessible resources Execute 3
- 28. <wps:ExecuteResponse xml:lang="en" service="WPS" serviceInstance="http://mon.serveur.com/wps/wps?"! statusLocation="http://mon.serveur.com/wps/wps?request=GetExecutionStatus&executionId=5e59-6dfe"! version="1.0.0" xmlns:wps="http://www.opengis.net/wps/1.0.0"! xmlns:ows="http://www.opengis.net/ows/1.1" xmlns:xlink="http://www.w3.org/1999/xlink">! <wps:Process wps:processVersion="1.0.0">! <ows:Identifier>urn:ogc:cstl:wps:otb:classification</ows:Identifier>! <ows:Title>Classification</ows:Title>! <ows:Abstract>Performs an image classification</ows:Abstract>! </wps:Process>! <wps:Status creationTime="2013-01-09T16:17:08.262Z">! <wps:ProcessAccepted>Process accepted</wps:ProcessAccepted>! </wps:Status>! </wps:ExecuteResponse>! ! Execute http://mon.serveur.com/wps?service=WPS&request=execute POST data+ statusLocation Server updates the content of statusLocation url regarding the processing progress. Once finished, status is set to <wps:ProcessSucceeded>.As a consequence, the Web client needs to periodically call the statusLocation url to determine the end of the processing
- 29. The major flaw in WPS 1.0 is the lack of true asynchronous process management...There is no way to cancel a launched process !
- 30. Web Processing Service WPS 2.0 (The next step)
- 31. WPS 2.0 adds process management operations - Dismiss, Pause, Resume and GetStatus. This set of operations is a must have to deploy asynchronous WPS - especially in the
- 32. GetStatus The GetStatus operation allows WPS clients to query the status of an asynchronously executed job Check 4 GetResult The GetResult operation allows WPS clients to query the result of a finished processing job. It is used in conjunction with asynchronous execution Retrieve 5 Dismiss The dismiss extension allows a client to cancel a job execution. The dismiss operation is a job control operation. Its availability is indicated p e r p r o c e s s u s i n g t h e j o b C o n t r o l O p t i o n s i n t h e P r o c e s s S u m m a r y a n d t h e ProcessOffering structures. Abort 6
- 33. Pause The Pause operation allows clients to pause an asynchronous execution request of a Process. Depending of the state of the Processing Job, its execution would not start or being paused. On successful pause, updated status is sent back with the state processPaused Pause 7 Resume The Resume operation allows clients to resume the asynchronous execution request of a Process in the sense of the Processing Job would be eligible again for execution. On successful resume, updated status is sent back with the state set to the state that Processing Job had when it have been paused Resume 8
- 34. WPS 2.0 should be officially approved as an OGC standard in fall 2014
- 35. WPS in action Simple GIS processing
- 37. It works pretty well !
- 38. But what about image processing ?
- 39. WPS in action Image processing - Assisted land cover classification
- 40. From pixel... Remote sensing image ...to information Land cover thematic map
- 41. Transferring a large volume of data is problematic True for upload (i.e. the input image) and download (i.e. the result) Issue...
- 42. Data and processes should be collocated Processing results should be downloaded only if needed Good option is to offer a Web service to visualize/manipulate results ...so
- 44. mapshup Web application http://mapshup.info WPSConstellation http://www.constellation-sdi.org Orfeo Toolbox Processing http://orfeo-toolbox.org
- 45. Orfeo Toolbox Remote sensing image library Open Source Developped by the French Space Agency Processing
- 46. Orfeo Toolbox More than 70 high level processing chains orthorectification segmentation classification etc. Processing
- 47. Orfeo Toolbox More than 70 high level processing chains orthorectification segmentation classification etc. Processing Supervised learning (land cover is computed from a set of "well known areas" given by user) Based on SVM (http://en.wikipedia.org/wiki/Support_vector_machine)
- 48. Constellation WPS Geospatial Networking Services OGC/ISO implementations Multi platform (JAVA) OpenSource WMS WFS CSW WPS
- 49. mapshup Improves access to geospatial data HTML + javascript Based on OpenLayers and jQuery Web application
- 50. WPSWPS a Web application 1 1 - DescribeProcess request for "Classification" Classification process description 2 2 - Set up MMI from process description +Image url Well known areas 3 3 - Execute an asynchronous "Classification" request Land Cover 4 4 - Display result retrieved as a WMS layer Orfeo Toolbox mapshup Image
- 52. Chaining WPS A chain of services
- 53. A WPS process is normally an atomic function
- 55. WPS A WPS C Data B Process with then process the result withData B WPS A WPS C
- 56. A Web client can be used to orchestrate a service chain that includes one or more WPS within a federation
- 57. Chaining WPS OWS-10 OGC testbed - Quality assessment and land cover services in a collaborative clouds environment
- 58. Note: this work is the result of the CNES/Astrium joint initiative within the « Open Mobility » thread - Cloud Computing of the OGC OWS-10 Testbed
- 59. Orthorectification of raw image ! Assess quality of the orthorectified image in terms of geometrical accuracy ! Compute Land Cover map from an orthorectified image Features
- 60. Client base processing chain workflow between multiple clouds ! Collaborative processing without raw data acquisition transfert between clouds ! WPS based on demand processing ! Integration of Orfeo Toolbox library within Constellation SDI Key points
- 61. mapshup http://mapshup.info Constellation SDIhttp://www.constellation-sdi.org Airbus Defense and Space WPS WPS WPS Web Client Orfeo Toolbox WMS CSW http://orfeo-toolbox.org/otb/
- 63. Orthorectify browser, everywhere Rome, Italy Toulouse, France Montpellier, France WMS WPS WPS Download WMS WPS CSW WMS Raw images Metadata + Reference 3D data Search catalog 1 Orthorectify raw image stored on a Terradue infrastructure using a reference database and processing chain located at Airbus Defense&Space infrastructure without moving the data
- 64. browser, everywhere Rome, Italy Toulouse, France Montpellier, France WMS WPS WPS Download WMS WPS CSW WMS Raw images Metadata + Reference 3D data Search catalog 1 Ask for Orthorectification 2 Orthorectify Orthorectify raw image stored on a Terradue infrastructure using a reference database and processing chain located at Airbus Defense&Space infrastructure without moving the data
- 65. browser, everywhere Rome, Italy Toulouse, France Montpellier, France WMS WPS WPS Download WMS WPS CSW WMS Raw images Metadata + Reference 3D data Search catalog 1 Ask for Orthorectification 2 Compute AOIs 3 Orthorectify Compute RPCs Orthorectify raw image stored on a Terradue infrastructure using a reference database and processing chain located at Airbus Defense&Space infrastructure without moving the data
- 66. browser, everywhere Rome, Italy Toulouse, France Montpellier, France WMS WPS WPS Download WMS WPS CSW WMS Raw images Metadata + Reference 3D data Search catalog 1 Ask for Orthorectification 2 Orthorectify Apply RPCs to generate orthoimage4 Compute AOIs 3 Compute RPCs Orthorectify raw image stored on a Terradue infrastructure using a reference database and processing chain located at Airbus Defense&Space infrastructure without moving the data
- 67. browser, everywhere Rome, Italy Toulouse, France Montpellier, France WMS WPS WPS Download WMS WPS CSW WMS Raw images Metadata + Reference 3D data Search catalog 1 Ask for Orthorectification 2 Stream orthoimage WMS layer 5 Orthorectify Apply RPCs to generate orthoimage4 Compute AOIs 3 Compute RPCs Orthorectify raw image stored on a Terradue infrastructure using a reference database and processing chain located at Airbus Defense&Space infrastructure without moving the data
- 68. browser, everywhere Rome, Italy Toulouse, France Montpellier, France WMS WPS WPS Download WMS WPS Orthoimage CSW WMS Raw images Metadata + Reference 3D data Assess Quality Assess orthoimage quality 6 Assess quality of the orthorectified image stored on Terradue infrastructure using a reference database and processing chain located at Airbus Defense&Space infrastructure without moving the data
- 69. browser, everywhere Rome, Italy Toulouse, France Montpellier, France WMS WPS WPS Download WMS WPS Orthoimage CSW WMS Raw images Metadata + Reference 3D data Assess Quality Compute AOIs Compute Errors 7 Assess orthoimage quality 6 Assess quality of the orthorectified image stored on Terradue infrastructure using a reference database and processing chain located at Airbus Defense&Space infrastructure without moving the data
- 70. browser, everywhere Rome, Italy Toulouse, France Montpellier, France WMS WPS WPS Download WMS WPS Orthoimage CSW WMS Raw images Metadata + Reference 3D data Assess Quality Stream error shift WMS layer 8 Compute AOIs Compute Errors 7 Assess orthoimage quality 6 Assess quality of the orthorectified image stored on Terradue infrastructure using a reference database and processing chain located at Airbus Defense&Space infrastructure without moving the data
- 71. Land Cover browser, everywhere Rome, Italy Toulouse, France Montpellier, France WMS WPS WPS Download WMS WPS Orthoimage Learning features CSW WMS Raw images Metadata + Reference 3D data Compute Land Cover from orthoimage (stored on cloud) 9 Compute Land Cover from orthorectified image stored on Terradue infrastructure using CNES OTB processing executed on Geomatys infrastructure
- 72. Land Cover browser, everywhere Rome, Italy Toulouse, France Montpellier, France WMS WPS WPS Download WMS WPS Orthoimage CSW WMS Raw images Metadata + Reference 3D data Learning features Compute Land Cover from orthoimage (stored on cloud) 9 Stream land cover map WMS layer 10 Compute Land Cover from orthorectified image stored on Terradue infrastructure using CNES OTB processing executed on Geomatys infrastructure
- 74. What’s next ? GSCB - Federated Project Pilot - WPS for the European Ground Segments
- 75. CNES DLR ESA Dream FedEO WPS OTB OpenSearch Landsat Dissharm Take 5 SPOT 4 Landsat 8 OpenSearch TerraSar-X Supersite WMS Search Search Visualize Process 1 1 2 3 Architecture Federated Project Pilot - GSCB