Re: [gdal-dev] VRT derived band pixel functions written in Python

2016-09-14 Thread jramm
Trying to run this using a function relying on scipy.ndimage... When running gdal_translate on the VRT, I get ImportError: No module named scipy.ndimage This comes after successfully import numpy. scipy.ndimage will happily import within the python interpreter. Any tips on how to track this

Re: [gdal-dev] VRT derived band pixel functions written in Python

2016-09-14 Thread jramm
Trying to run this using a function relying on scipy.ndimage... When running gdal_translate on the VRT, I get ImportError: No module named scipy.ndimage This comes after successfully import numpy. scipy.ndimage will happily import within the python interpreter. Any tips on how to track this

Re: [gdal-dev] Memory increase in postgis raster driver

2016-08-12 Thread jramm
Hi We have been looking into this problem some more. So it seems we can reproduce this by using postgis raster tiles of 100 x 100. raster2pgsql cmd was: raster2pgsql bigtiff.tif -C -r -s 27700 -t 100x100 -P -I -M -Y | psql The effect seems more pronounced using GDAL 2.2 (trunk) vs GDAL 2.1

Re: [gdal-dev] GDAL raster processing library?

2016-08-08 Thread jramm
Hi Ari, I began some work to clarify my ideas here: www.github.com/JamesRamm/GeoAlg perhaps there is potential for merging with your project? For neighbourhoods I provide 2 iterators - one simple block based and one 'buffered'. The block can be the natural block or user defined. I also planned to

Re: [gdal-dev] Call for discussion on RFC 63 : Sparse datasets improvements

2016-07-22 Thread jramm
Forgive me a newbie question but I'm not so familiar with the RFC process: - Is there any kind of timescale for this appearing in trunk or what needs to happen for that to happen? -- View this message in context:

[gdal-dev] Memory increase in postgis raster driver

2016-07-20 Thread jramm
I am seeing a continuous, linear memory increase when reading sequential windows of a large postgis dataset. This is the same regardless of my GDAL_CACHEMAX settings If I run he same code on an equivalent GTiff dataset, I do not see the same increase in memory. I can see that the postgis dataset

Re: [gdal-dev] Error in GDALWarp to NWT_GRD

2016-07-14 Thread jramm
I added the following to the end of the Create method in frmts/northwood/grddataset.cpp: vsi_l_offset nFileSize = 1024 + nXSize * nYSize * 2; if (VSIFTruncateL(poDS->fp, nFileSize) != 0) { CPLError(CE_Failure, CPLE_FileIO, "Failed to

Re: [gdal-dev] Error in GDALWarp to NWT_GRD

2016-07-13 Thread jramm
jramm wrote > gdalwarp -of NWT_GRD -ot Float32 -t_srs EPSG:4326 test.tif test.grd > > very quickly returns Sorry this meant to read: very quickly returns: 0ERROR 1: /home/jamesramm/test.grd, band 1: IReadBlock failed at X offset 0, Y offset 0 ERROR 1: GetBlockRef failed at X block of

[gdal-dev] Error in GDALWarp to NWT_GRD

2016-07-13 Thread jramm
I have a strange error when reprojecting a dataset to NWT_GRD format. e.g. gdalwarp -of NWT_GRD -ot Float32 -t_srs EPSG:4326 test.tif test.grd very quickly returns Stepping through, I've traced this to a call to `GetLockedBlockRef` in IRasterIO (rasterio.cpp) which is called when GDALWarp

Re: [gdal-dev] GDAL raster processing library?

2016-07-13 Thread jramm
I can see where some similarities with other new and existing GDAL work could be a blocker on this, but I also think this adds a a degree more flexibility allowing potentially any kind of complex processing to be carried out without worrying/bothering about boilerplate. It would be good to find

Re: [gdal-dev] Call for discussion on RFC 63 : Sparse datasets improvements

2016-07-10 Thread jramm
Even Rouault-2 wrote > For GeoTIFF, the unit of query remains the block. So if a block is missing > is > present, it computes how many pixels of the window of request intersect > the > block, and count them as present. > > Imagine that you have a raster of dimensions 20x20, with tiles of size >

[gdal-dev] File Geodatabase raster driver

2016-07-07 Thread jramm
Based on Even's work on FGDB vector, I have begun looking at raster data, here: https://github.com/JamesRamm/fgdb_raster_spec So far everything I've found is pretty much based on the output of v the dump_gdb script. I have two troubling areas currently blocking progress 1. I can locate pixel

Re: [gdal-dev] gdalbuildvrt for multiband files?

2016-06-20 Thread jramm
Two options: 1. Use the xml module in python to build up the VRT file. You would create a VRTRasterBand node for each band of each file. Note you will need to figure out the maximum extent and raster size (in pixels) first, so this will be easiest if you enforce the same pixel size and projection

[gdal-dev] Create standalone PAM datasets?

2016-06-16 Thread jramm
Does GDAL offer any functionality (in the python bindings) to create a PAM dataset (.aux.xml file) without a 'main' dataset attached? This is a useful metadata container that we would like to use for other formats (e.g. non spatial CSV file, which might share the same custom metadata as a

[gdal-dev] Pass clipsrc to VectorTranslateOptions

2016-06-13 Thread jramm
Im using VectorTranslate and VectorTranslateOptions in python bindings. It seems like there is nothing equivalent to the ogr2ogr -clipsrc option in VectorTranslateOptions. Is there another way of passing this in? -- View this message in context:

[gdal-dev] Discover whether a GDALDataset is raster or vector?

2016-06-06 Thread jramm
Hi Given a GDALDataset pointer, which has been opened using GDALOpenEx(...), what is the best way to discover whether the dataset is raster or vector? I have thought of checking the drivers' metadata for GDAL_DCAP_OF_RASTER or VECTOR, but this could potentially return YES for both if it is e.g

Re: [gdal-dev] Read data without reading 'null data'

2016-06-06 Thread jramm
This is my mistake. I had not truly created a sparse raster! I keep forgetting that the gdal tools (gdal_translate) will still write the sparse blocks and the sparse creation option is just to indicate that FillEmptyBlocks should be skipped. Creating the sparse file by hand correctly sets the

Re: [gdal-dev] Read data without reading 'null data'

2016-06-06 Thread jramm
Hi I am having a few problems with using this (via python). I have a test dataset with a 16 x 16 blocksize. In the below examples, bnd = ds.GetRasterBand(1) First, I try getting the blocksizes using the metadata: This gives: None of the first 10 blocks are empty - this is strange as it is

Re: [gdal-dev] How to consider data types when implementing IWriteBlock

2016-05-25 Thread jramm
As an update to this; I have finished write support for the GRD driver for now, with ZMAX/ZMIN exposed as creation options and will be explicitly calculated in CreateCopy if not passed in - exactly as you suggested Even, thanks. I'm waiting permission to get a osgeo user id so I can raise a

Re: [gdal-dev] Geotiff FillEmptyTiles with no data value?

2016-05-10 Thread jramm
Hi I have made changes to FillEmptyTiles so that if nodata is set, then it will always fill with nodata, otherwise 0. I have attached the raw diff...I have no idea how to submit a change request/review etc? fillempty_nodata.diff

Re: [gdal-dev] Geotiff FillEmptyTiles with no data value?

2016-05-06 Thread jramm
NoDataValue is set on a band level and FillEmptyTiles operates at a dataset level. I've never heard of a geotiff with different nodata per band - is this even possible, or would it be reasonable to take the nodatavalue of the 1st band and use this to initialise the empty tiles block? Then there

Re: [gdal-dev] Segfault in GDALWriteBlock

2016-05-06 Thread jramm
im building off trunk, so Gdal2.1dev Ill get that stack trace... -- View this message in context: http://osgeo-org.1560.x6.nabble.com/Segfault-in-GDALWriteBlock-tp5264660p5264899.html Sent from the GDAL - Dev mailing list archive at Nabble.com. ___

[gdal-dev] Segfault in GDALWriteBlock

2016-05-05 Thread jramm
Hi I am getting a segfault in a call to GDALWriteBlock with this code: Stepping through seems to suggest that the segfault is arising from line 171 of "geo_new.c" in libgeotiff: I cant find previsely what it is I have done wrong to cause this in my codeany ideas? -- View this message

[gdal-dev] Geotiff FillEmptyTiles with no data value?

2016-05-03 Thread jramm
Hi When writing geotiffs, if I dont write blocks they will automatically be filled on close by the FillEmptyTiles. It appears that this will only fill with zeros - is it possible to make it fill with the no data value instead? This is potentially a huge time saver when processing a large, fairly

Re: [gdal-dev] How to consider data types when implementing IWriteBlock

2016-04-19 Thread jramm
Even Rouault-2 wrote > Skimming through the code, it seems you must provide zmin / zmax to do the > scaling of floating point elevations to integral values. So either it is > user > provided, or you do a prior statistics computation in CreateCopy() if the > input dataset hasn't min/max

Re: [gdal-dev] How to consider data types when implementing IWriteBlock

2016-04-18 Thread jramm
Hi I have implemented the write support in the NWT_GRD format, having to make a few compromises. I'd like to go through them and see if they are reasonable. I have also attached the diff. 1. The existing read driver reports 4 bands for a GRD dataset. The first 3 are essentially 'virtual' - they

[gdal-dev] How to consider data types when implementing IWriteBlock

2016-04-12 Thread jramm
Hi I am adding write support for the Northwood Grid (Vertical Mapper/MapInfo format) driver. This format only allows 32 bit float as the datatype, and to make things more tricky it actually stores this on disk as either 16 or 32 bit ints, using scaling rules. The current read driver applies the

Re: [gdal-dev] Implementing write support for GDAL driver

2016-03-30 Thread jramm
is not entirely necessary - mostly a shortcut when writing a whole dataset to another, but I've not looked closely at it yet. On 30 March 2016 at 16:36, Even Rouault-2 [via OSGeo.org] < ml-node+s1560n5258858...@n6.nabble.com> wrote: > Le mercredi 30 mars 2016 17:17:11, jramm a écrit :

[gdal-dev] Implementing write support for GDAL driver

2016-03-30 Thread jramm
Hi I am implementing a write driver for the Vertical Mapper/Northwood Grid format (NWT_GRD), which already has read support. I have attached a diff of what I have got so far. Needless to say, it is not complete or working :D. I'm looking for information on development, specifically: - Precisely

[gdal-dev] Standard GDAL format for HDF5?

2016-02-29 Thread jramm
I was wondering if there would be any interest in a standard GDAL format for HDF5 files? The major problem I have with current formats supported by the HDF5 driver is that they are very application-specific, with requirements on the structure of groups and group names. What I propose would make

[gdal-dev] Read data without reading 'null data'

2016-02-19 Thread jramm
We are storing large raster datasets (~500,000 x 500,000) in geotiff files. The array data is typically very sparse (density is 0.02% or less) and compression greatly reduces the geotiff size. However, when processing data we read the data in chunks, which are automatically decompressed..this

[gdal-dev] GDAL Postgis Driver using SPI?

2016-01-26 Thread jramm
Hi I am working on a project to manipulate huge rasters in a postgis database. In order to achieve best performance, we are implementing most of our code 'server-side', e.g. as a postgresql extension. It occurs to me that another GDAL postgis driver using SPI

Re: [gdal-dev] Proposed Block iterator API

2015-11-22 Thread jramm
Yes this would be incredibly useful. We typically process >100GB rasters and so iterating in 'windows' is a must for us. We have typically implemented a solution outside of GDAL, with a 'next' function that looks something like this: int RasterWindow::next() { static int windowNoX = -1;

[gdal-dev] Transform raster based on values in shapefile attribute table

2015-09-17 Thread jramm
I have a raster (.tif), which has an accompanying shapefile attribute table (.dbf). Basically, every value in the raster is a key into the attribute table, which has a number of fields (there is a 'Value' field which is the 'key' corresponding to the raster values, then a number of attributes). I

Re: [gdal-dev] Where can I find ogr_FileGDB.dll v1.4 compilled for Windows?

2015-08-21 Thread jramm
You can get full binary distributions for windows (including) ogr_FileGDB.dll from http://www.gisinternals.com/ They dont seem to have it in msvc_1800 releases, but in 1700 and 1600. You will also need the FileGDB API dll from ESRI. You can get this from the ESRI website (you will need to

[gdal-dev] memory leak in gdal program

2015-08-21 Thread jramm
I'm using GDAL 201 to iterate features in a geodatabase feature class and add a new text field, whose value depends on the integer value in another field.It gives a fairly large memory leak (approx 1GB for every 1m features iterated). I'm not sure where the leak isany ideas?The full code:int

[gdal-dev] gdal_rasterize increase memory usage

2015-07-16 Thread jramm
gdal_rasterize is limited to use just 10MB of memory (line ~640 of gdalrasterize.cpp). Is there anyway to change this (without having to recompile?) I'm noticing that changing the output data format from Byte to Int16 or even Int32 drastically reduces performance. This must be because the strict

[gdal-dev] gdal_rasterize in multiple processes

2015-07-14 Thread jramm
I have a number of vector datasets to rasterize. I am finding that when the datasets are small, I have no problem starting multiple gdal_rasterize processes (using python). If my datasets are large (I'm trying to create rasters with millions of pixels), I'm finding that I can only start one

[gdal-dev] GDAL query creation options?

2015-06-11 Thread jramm
Is there a way to programatically query what dataset creation/layer creation options are available for a driver?I'd like to be able to do something like: driver-listDCO(*options) -- View this message in context: http://osgeo-org.1560.x6.nabble.com/GDAL-query-creation-options-tp5210356.html

[gdal-dev] gdal_rasterize does not burn polygon attributes

2015-06-11 Thread jramm
I'm running gdal_rasterize, trying to make it create a new tif from polygons, using an attribute field as the burn value. Here is my command: gdal_rasterize -tr 5 5 -a SOP -l test -a_nodata 0 test.shp test.tif I end up with an image that is all 0's. The shapefile is correct and can be read by

Re: [gdal-dev] Raster attribute tables in GDAL?

2015-05-21 Thread jramm
-node+s1560n5206664...@n6.nabble.com wrote: Le mercredi 20 mai 2015 15:57:38, jramm a écrit : Does GDAL have any support for writing ESRI-style raster attribute tables? These are the .vat.dbf files that often accompany geotiffs and other formats I wasn't particularly aware of those

[gdal-dev] Raster attribute tables in GDAL?

2015-05-20 Thread jramm
Does GDAL have any support for writing ESRI-style raster attribute tables? These are the .vat.dbf files that often accompany geotiffs and other formats -- View this message in context: http://osgeo-org.1560.x6.nabble.com/Raster-attribute-tables-in-GDAL-tp5206653.html Sent from the GDAL -

[gdal-dev] Formats that support RAT's?

2015-04-28 Thread jramm
It seems GDAL will always let you create a Raster Attribute Table (in memory) but may fail when writing to disk depending on whether the format supports it? I can't seem to find any information anywhere on what formats support RAT's? Is there a list I can refer to ?? -- View this message in

Re: [gdal-dev] GDAL slow to write GeoTIFF?

2015-04-28 Thread jramm
David, there should be no compression, but I will try setting it explicitly in the driver... -- View this message in context: http://osgeo-org.1560.x6.nabble.com/GDAL-slow-to-write-GeoTIFF-tp5203128p5203203.html Sent from the GDAL - Dev mailing list archive at Nabble.com.

[gdal-dev] GDAL slow to write GeoTIFF?

2015-04-27 Thread jramm
I'm writing a custom processing program using GDAL in C. I'm processing a raster of roughly 150 000 * 200 000 pixels in windows of 256 * 256 pixels. I'm finding that traversing the raster and applying some basic processing to each of the windows takes very little time; about 10 minutes on my