[gdal-dev] What happens by default when writing RGBA into jpeg?

Hi, I would like to know what happens if I convert an original RGBA tiff image into jpeg as gdal_translate -of jpeg rgba_in.tif jpeg_out.jpg I know that for getting a good result I can add -b 1 -b 2 -b 3 but I am curious to know what happens and how GDAL computes sort of a transparent sepia

Re: [gdal-dev] What happens by default when writing RGBA into jpeg?

Selon Jukka Rahkonen jukka.rahko...@mmmtike.fi: Hi, I would like to know what happens if I convert an original RGBA tiff image into jpeg as gdal_translate -of jpeg rgba_in.tif jpeg_out.jpg I know that for getting a good result I can add -b 1 -b 2 -b 3 but I am curious to know what

Re: [gdal-dev] What happens by default when writing RGBA into jpeg?

Even Rouault even.rouault at mines-paris.org writes: Selon Jukka Rahkonen jukka.rahkonen at mmmtike.fi: Hi, I would like to know what happens if I convert an original RGBA tiff image into jpeg as gdal_translate -of jpeg rgba_in.tif jpeg_out.jpg I know that for getting a good

Re: [gdal-dev] What happens by default when writing RGBA into jpeg?

Selon Jukka Rahkonen jukka.rahko...@mmmtike.fi: Even Rouault even.rouault at mines-paris.org writes: Selon Jukka Rahkonen jukka.rahkonen at mmmtike.fi: Hi, I would like to know what happens if I convert an original RGBA tiff image into jpeg as gdal_translate -of jpeg

[gdal-dev] Control overview block size

Hi List, Is there a way to control the block size of overviews and inspect that block size from gdalinfo ? I have a raster with 256x256 block size. Band 1 Block=256x256 Type=Byte, ColorInterp=Red Band 2 Block=256x256 Type=Byte, ColorInterp=Green Band 3 Block=256x256 Type=Byte, ColorInterp=Blue

Re: [gdal-dev] Control overview block size

Selon Etienne B. Racine etienn...@gmail.com: Hi List, Is there a way to control the block size of overviews and inspect that block size from gdalinfo ? I have a raster with 256x256 block size. Band 1 Block=256x256 Type=Byte, ColorInterp=Red Band 2 Block=256x256 Type=Byte, ColorInterp=Green

Re: [gdal-dev] What happens by default when writing RGBA into jpeg?

Even Rouault even.rouault at mines-paris.org writes: Hi Even, Sorry, I must have been unclear. The question was about writing out a real JPEG file, not JPEG compressed TIFF Ah my fault. I read too fast. The command gdal_translate -of jpeg rgba_in.tif jpeg_out.jpg creates a jpeg

Re: [gdal-dev] VRTDataset in Java

Do we have plans to add those entries to the GDAL API (C, Java, etc.)? -- \...\GDAL\TRUNK\FRMTS\VRT\GDAL_VRT.H VRTDatasetH CPL_DLL CPL_STDCALL VRTCreate( int, int ); CPLXMLNode CPL_DLL * CPL_STDCALL VRTSerializeToXML( VRTDatasetH, const char * ); CPLErr CPL_STDCALL VRTAddSource(

Re: [gdal-dev] What happens by default when writing RGBA into jpeg?

Thanks, that makes sense. However, the result is somehow surprising and I guess that in most cases unusable for the user. I wonder if it would be good to print something like WARNING. Encountered 4 source bands, assuming CMYC color space. Behaviour is not very easy to understand by reading

Re: [gdal-dev] VRTDataset in Java

Ivan, gdal_vrt.h is an already installed header file and the symbols are exported (CPL_DLL), so this is a public C API (although a bit confidential probably) As far as SWIG bindings is concerned, some work would be needed. New shadow types should be introduced to model VRTDataset and

Re: [gdal-dev] What happens by default when writing RGBA into jpeg?

On Tue, Jun 10, 2014 at 6:28 AM, Even Rouault even.roua...@mines-paris.org wrote: Thanks, that makes sense. However, the result is somehow surprising and I guess that in most cases unusable for the user. I wonder if it would be good to print something like WARNING. Encountered 4 source bands,

[gdal-dev] Question regarding OGRPolygon intersection

Hi, I was hoping to use GDAL for testing when two convex polygons intersect. I was able to do this with something similar to: polyOne-Intersects(polyTwo); Both polyOne and polyTwo are OGRPolygon and are defined in geographic coordinates, i.e. latitude and longitude (decimal degrees). I've

Re: [gdal-dev] Question regarding OGRPolygon intersection

Silas, More exactly, GEOS is a port in C++ of JTS. It does exactly what JTS does for this, so it considers the coordinates as being located on a 2D cartesian plane. No spherical/ellipsoidal geometry is involved. Even Hi, I was hoping to use GDAL for testing when two convex polygons

Re: [gdal-dev] Question regarding OGRPolygon intersection

Thanks Even! Silas - Original Message - From: Even Rouault even.roua...@mines-paris.org To: Silas Faltus fal...@spacecomputer.com Cc: gdal-dev@lists.osgeo.org Sent: Tuesday, June 10, 2014 11:17:32 AM Subject: Re: [gdal-dev] Question regarding OGRPolygon intersection Silas, More

Re: [gdal-dev] Control overview block size

Indeed, thanks a lot Even. The OVR in GDAL_TIFF_OVR_BLOCKSIZE made me believe it was only for external .ovr overviews. Etienne 2014-06-10 8:48 GMT-04:00 Even Rouault even.roua...@mines-paris.org: Selon Etienne B. Racine etienn...@gmail.com: Hi List, Is there a way to control the block

Re: [gdal-dev] VRTDataset in Java

Hi Even, Date: Tue, 10 Jun 2014 17:43:50 +0200 From: even.roua...@mines-paris.org To: lucena_i...@hotmail.com CC: gdal-dev@lists.osgeo.org Subject: Re: [gdal-dev] VRTDataset in Java Ivan, gdal_vrt.h is an already installed header file and the symbols are exported (CPL_DLL), so this is

Re: [gdal-dev] GDAL may create slow GPKG/SQLite indexes

Even Rouault even.rouault at mines-paris.org writes: Jukka, I tried to simulate your scenario but couldn't observe any performance difference (on Linux, but I doubt that the OS would make a difference) when generating a test DB with 3.7.9 or 3.7.14, and using it with the other