2
votes
3answers
36 views

Use GDAL command line to copy projections

I have two images, a georeferenced Tiff and a second Tiff without a reference. The second image is a copy of the first, but it lost its reference. Now, I want to copy the reference from the first Tiff ...
0
votes
0answers
31 views

analysis of srtm data for gaps

I need to analyse the SRTM DATA (1025 X 1025) of a particular terrain which has gaps or voids. Could anybody suggest a solution to find the percentage of gaps or voids in the SRTM data? I would like ...
4
votes
1answer
67 views

Why the result of a merge of multiple raster is so big?

I try to merge 14 geotiff like this : Each geotiff is about 50Mb. I need a geotiff at the output My workflow : gdalbuildvrt -input_file_list list.txt test.vrt (where my list contains the name ...
0
votes
0answers
21 views

How to view a raster in CartoDB?

What is the easiest way to view a raster in CartoDB? From the list of formats that you can upload into CartoDB, I noticed that .tif is available, so I've tried adding a GeoTIFF, but it says that ...
0
votes
1answer
40 views

GeoTIFF created using ArcGIS for Desktop not displaying in Google Earth or Photoshop?

I originally had an IMAGINE Land Cover raster file that I opened in ArcMap. I used the Extract Feature from Raster to extract only the Developed class and saved it (still IMAGINE). Then I used the ...
1
vote
2answers
29 views

qgis raster style 'no data value' checkbox is ignored - what's a good workaround?

See bug report filed here: http://hub.qgis.org/issues/10236 Note the initial bug report got 'fixed' but that fix introduced this new error, so the issue was reopened a few days ago. Anyway, it ...
0
votes
0answers
24 views

GeoTIFF Mosaic/Crop/Translate: Easiest Method in QGIS?

I routinely have to mosaic multiple GeoTIFFs together, extract a rectangular area, and save that area as a JPG with a world file. Typically I've been using commercial software for that (Geographic ...
0
votes
1answer
47 views

GDAL TIF to JPG Creates Dark Image

I'm using the GDAL Raster>Translate to create JPGs from Georeferenced TIFs. The translation is working, but the resulting JPGs are significantly darker than the TIFs they are being created from. ...
0
votes
1answer
34 views

How do I mask a raster in TileMill?

I've tried just about every single TileMill compositing operation on the vector and raster layers in question, and I have to admit that I can't figure it out: How the heck can I mask a raster with a ...
0
votes
1answer
32 views

Is there an easy way to refresh / update a raster tif file in GIS?

Apologies for the newbie / basic question, but it seems to be a fairly simple concept which I can't get to work properly, and I'd be really grateful for a pointer or two! I have a load of different ...
0
votes
1answer
22 views

Importing a Geotiff into WhiteBox

I am looking for an opensource solution to create a seamless air photo mosaic. I came across WhiteBox from the University of Guelph which seems like it might do the trick, but it does not support ...
0
votes
2answers
249 views

using Python to calculate NDVI, output as a Geotiff

I need a script that can calculate NDVI from two separate input Geotiff files, then output the results as a Geotiff. I wrote following script, most of which is borrowed from various on-line sources ...
1
vote
3answers
284 views

Topography: How to get the x,y,z coordinates of highest or lowest point/pixel of a raster GIS?

Given a .tiff topographic raster image with mountains and deep sea, I am looking for the x,y,z specifics of the highest or lowest point. The x,y,z values being: altitude (z-coordinate) latitude ...
0
votes
1answer
100 views

How to load Georeferenced Scanned Maps in R

I have a geo-referenced scanned Map in GeoTiff format, which I would like to load into R. My intention is to plot some vector data (points and polygons) over this map using maptools package. Is ...
1
vote
2answers
61 views

How can i combine the colours of one raster with values from another

I have two Tiffs with data from the same area. One is in colour and when I use the identify shows a 'color index' number (eg. 141), then Color(a,r,g,b)(eg. 255,90,255,0). The other tiff contains a ...
0
votes
0answers
80 views

Geoserver raster (in geotiff format) becomes black when grouped by other layers in vector format?

Good day, I am a newbie in field of GIS systems. Currently I have an issue when grouping layers, raster and vector. I would like to use satellite image in geotiff format as a base layer. It works ...
0
votes
2answers
63 views

Two r.mapcalc calculations return a much bigger raster cell size than the input raster

I tried the following calculations with a GeoTiff sample, having a cell size of 25m: Calculating the togographic exposure (TOPEX) and estimating the mean topographic curvature Both, the resulting ...
1
vote
0answers
83 views

Touch up tool for rasters?

I was wondering if it were at all possible to manipulate/massage rasters (eg Geotiff) using Qgis plugins or Grass?? By manipulate, I mean manually smooth off interpolation artefacts, blended surface ...
1
vote
1answer
115 views

GeoTIFF without projection?

I have encountered a GeoTIFF raster files with EPSG:4326 (WGS84), i.e. no projection defined! Is this normal? I would expect raster to be in Projected Coordinate System. Raster is a grid of pixels so ...
1
vote
2answers
142 views

Some tiff not included on a vrt index

I have some tiff files and I'm trying to generate a vrt index with gdal tool, gdalbuildvrt. I run this command: gdalbuildvrt orto_index.vrt -srcnodata "0 0 0" -vrtnodata "0 0 0" *.tif and throws ...
2
votes
1answer
215 views

Black zones after tiling two tiff files

I have two Geotiff files. with one side overlapping. Each Geotiff is surrounded by a black frame. I have created an Image Pyramid with Geoserver 2.3.0 but when I try to see the layer on OpenLayers, ...
0
votes
1answer
1k views

Help dealing with a GeoTiff-file in ArcGIS

I'm doing data-analysis on satellite data and my source data is in GeoTiff-file format. What I would like to do with the data is: 1) Open the raster data in ArcMap etc. 2) Change the coordinate ...
2
votes
1answer
88 views

Is JAI really that usefull for raster images on Geoserver?

I've been going back and forth with JAI for quite a while by now. I've never been really impressed with it to be honest. Is it really all that jazz that I hear people talk about? The problem with JAI ...
2
votes
2answers
2k views

How to convert .geotiff --> .tiff?

How to convert .geotiff files to .tiff files (ordinary plain images)? Basically, I have cropped the image to a rectangle of interest and knowing its left-lower location and having chosen the pixel ...
6
votes
2answers
293 views

How to generate TFW files for a list of images?

I have a few digital images that are not georeferenced. E.g.: Img01.tif Img02.tif ... Img99.tif On the other hand, I have a text file, which contains georeferencing information for these ...
3
votes
1answer
329 views

How to get Lon/Lat values from the postgis raster type column

I have a tiff raster in my PostGIS 2.0 database. I want to get the value lat/lon and extra data like temperature from the raster type column in postgis table. I want the table with columns ...
2
votes
1answer
353 views

MrSid => GeoTiff

I have a MrSid file that I would like to convert to a GeoTiff. Is there a way to do this on a Mac running Mountain Lion? I know it can be done on Windows and Linux using the LizardTech command line ...
0
votes
2answers
501 views

Grass 7 / ArcGIS 9.3 - tiff to raster

Again a Grass 7 question. I have the output of a modelling run as matlab file, which I can export as tiff and load as geotiff. OK - now can I extract the data/convert this tiff into a raster proper? ...
3
votes
3answers
1k views

GDAL_translate: converting ESRI GRID to Geotiff in batch

The Challenge: To batch convert 1000 rasters in ESRI Grid binary to Geotiff using either using a batch file or Python 2.7 without ArcGIS/Arcpy module. The Tools: Win7Pro, GDAL 1.9.2 (via OSGeo4W), ...
2
votes
0answers
134 views

How to geocorrect in qgis?

I need to fit a utm wgs84 tiff raster to a topomap in the same projection. I use GCP and it invariably fails. The first raster uncorrected rater superimpose well, the "geocorrected" raster is ...
4
votes
1answer
357 views

Recoloring geotiff for visual presentation

I have a rather big Geotiff. It is the mosaic of four RapidEye satellite images. They are all a bit bland/grayish. When combined I would like to freshen up their colors so that they are more visually ...
2
votes
0answers
164 views

Overlay Shapefile onto Geotiff

I have a Geotiff map and I want to overlay a Shapefile onto it. Ideally I want to specify a 'nice' style for the polygons e.g. have them opaque (for now all polygons should be the same). I want to ...
0
votes
1answer
189 views

Setting projection to a geotiff file when it's shown as Unknown

I have a geotiff file that has no CRS in the metadata but I know that the CRS of the raster is WGS 84 UTM 22 N. How can I modify the geotiff file to have the CRS WGS 84 UTM 22 N in the metadata. ...
5
votes
1answer
859 views

Why do TIF loaded into PostGIS lose their colormap?

I have successfully loaded a TIF image (using raster2pgsql) into my PostGIS 2.0.1 database. I can load the raster image into QGIS and it displays in the correct space. However, it has lost all colour ...
6
votes
1answer
1k views

Creating a mask with transparent pixels in python

I have a geotiff image with pixel intensities ranging between certain values. Lets say bewteen -2 and 2 (the image is normalized). I have a certain threshold which interests me, lets sat 1. I would ...
1
vote
2answers
131 views

Display Rectangular Data Grid

I'd like a Linux program which displays ASCII ArcGrid files (NxM rectangular ASCII data grids which may have either integer or floating point values). There is no practical upper or lower limit to ...
2
votes
1answer
98 views

Global composite of radar data available?

Iowa State offers an exceptional NEXRAD composite image as GeoTIFF for the entire continental US at a reasonable resolution. Is there a comparable GeoTIFF composite updated semi-regularly available ...
3
votes
1answer
124 views

rgb2pct.py increases size of file 20 fold!

I wanted to reduce the number of bands of a tif file from 3 to 1... I used this command rgb2pct.py -n 256 fnp_braunschweig.tif fnp_bs.tif and it increased the size from 31mb to 778mb I actually ...
9
votes
2answers
422 views

What is the correct way to convert a USGS Orthoimage from WorldImage format to tiled GeoTiff for GeoServer?

USGS provides different resolution orthoimage quadrangles in the WorldImage format (*.tif with an accompanying *.tfw world file). Some of these quadrangles can be used by GeoServer (2.1.0 - 2.1.2) by ...
4
votes
2answers
589 views

Extract all pixels of given RGB value and render as MultiPolygons

Given a geotiff image with a colortable in it, what is the easiest way to extract each color as its own "layer or shapefile or multipolygon object"? Specifically, I am looking for a programmatic ...
2
votes
2answers
901 views

How to convert from GeoTIFF to PNG/JPG and Web Mercator in Java?

I'd like to convert raster image from (geo)tiff to an png/jpg and afterwards if it is necessary ... I'd like to convert the coordinates with help of EPSG-Codes to the OSM/Google Projection(EPSG: ...
6
votes
2answers
1k views

Easily find centre point of a raster in ArcMap 10 document?

If I have, say, a rectangular and georeferenced raster file loaded in an ArcMap 10 document (.tiff w/ associated tfw), how do I easily find its centre point and store that point in a points vector ...
15
votes
5answers
924 views

Speed of various raster data formats

I'm having trouble locating any discussion or comparative benchmarking of different raster file formats (e.g., for use in data analysis in R). Does anybody have any insight into why particular formats ...
8
votes
3answers
750 views

Best way to manage large number of geoTiff rasters

I have around 2-3000 1-bit geoTiffs of size 11000x9400. Color 0 should be transparent, and QGis gets it wrong in the first place, so I used a .vrt file to set all the parameters in one single place. ...
2
votes
1answer
609 views

GeoTIFF raster layer, c#

We have a map rendering engine (renders from MapInfo Interchange Format). This engine uses Mercator Projection. Now we have to insert a raster layer (orthophotos of a city), we have GeoTIFF files with ...
3
votes
2answers
1k views

JPG file all black when added as raster in QGIS

I add a new raster layer in the latest QGIS and select a JPG file, but it is all black. I tried adding the TIF version of the same image and that worked. What is it with the JPG, and how should I ...