Hi list, I have seen a recent email on that list about filling empty tiles and SPARSE_OK creation option (titled "Geotiff FillEmptyTiles with no data value") I would like to understand a little better how it works.
Suppose I have 2 isolated GeoTiff files of the same datatype, let's say one covering California and the other covering France. I do a gdalbuildvrt to mosaic them together and then I convert the VRT to GeoTiff. At which level the SPARSE_OK flag and void blocks management are taken into account? I was "hoping" that using the SPARSE_OK=TRUE create option when translating VRT to GeoTiff would have resulted into having an output smaller with respect to an output generated without that creation option since there is a wide void area in the middle. Why I get the same size in both cases? Shouldn't it avoid filling void blocks in the gap? Is the VRT Driver iterating on all the tiles involved in the final bounding box so that it forces a write of each block even if there is no source dataset for that tile? Please, let me know. Best Regards, Daniele -- == GeoServer Professional Services from the experts! Visit http://goo.gl/it488V for more information. == Ing. Daniele Romagnoli Senior Software Engineer GeoSolutions S.A.S. Via di Montramito 3/A 55054 Massarosa (LU) Italy phone: +39 0584 962313 fax: +39 0584 1660272 http://www.geo-solutions.it http://twitter.com/geosolutions_it ------------------------------------------------------- *AVVERTENZE AI SENSI DEL D.Lgs. 196/2003* Le informazioni contenute in questo messaggio di posta elettronica e/o nel/i file/s allegato/i sono da considerarsi strettamente riservate. Il loro utilizzo è consentito esclusivamente al destinatario del messaggio, per le finalità indicate nel messaggio stesso. Qualora riceviate questo messaggio senza esserne il destinatario, Vi preghiamo cortesemente di darcene notizia via e-mail e di procedere alla distruzione del messaggio stesso, cancellandolo dal Vostro sistema. Conservare il messaggio stesso, divulgarlo anche in parte, distribuirlo ad altri soggetti, copiarlo, od utilizzarlo per finalità diverse, costituisce comportamento contrario ai principi dettati dal D.Lgs. 196/2003. The information in this message and/or attachments, is intended solely for the attention and use of the named addressee(s) and may be confidential or proprietary in nature or covered by the provisions of privacy act (Legislative Decree June, 30 2003, no.196 - Italy's New Data Protection Code).Any use not in accord with its purpose, any disclosure, reproduction, copying, distribution, or either dissemination, either whole or partial, is strictly forbidden except previous formal approval of the named addressee(s). If you are not the intended recipient, please contact immediately the sender by telephone, fax or e-mail and delete the information in this message that has been received in error. The sender does not give any warranty or accept liability as the content, accuracy or completeness of sent messages and accepts no responsibility for changes made after they were sent or for other risks which arise as a result of e-mail transmission, viruses, etc.
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