Raster is a data format consisting of regular grids of values, usually stored in an image-like format.

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Problem with converting rasters to arrays and adding them to main array, then converting to raster via NumPyArrayToRaster : output is NoData values

I have a process that aims to loop through a list of rasters (testing with only 3) covert each raster to an array, add the array to an existing 'template' array, then save the final array back to a ...
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43 views

calculate the needed space for a raster pyramide withqgis

how can i calculate (or where can I find information to calculate) the required disk space for a raster map of 36GB which should be in a pyramide of 10 levels ? Regards, D3
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6answers
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How do I iterate through every cell in a continuous raster?

See this link for more details. The Problem: I want to loop through a continuous raster (one that has no attribute table), cell by cell, and get the value of the cell. I want to take those values ...
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2answers
1k views

How to extract subdataset from HDF raster?

I am trying to extract a subdataset from HDF raster. Later on, I intend to make operations such as mosaicking and extracting raster averages from the extracted subdataset. The following code is ...
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0answers
190 views

Modifying Raster Layer with Python Console

Forgive me if this has been asked somewhere else. I am looking for a way to edit a raster file which has already been loaded into QGIS through the python console (i.e. I would like to edit the raster ...
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1answer
99 views

Update Grid cell value with Point attribute

I have a 4km gridded dataset with each grid cell value as a measurement of precipitation. I would like to update it with a point shapefile of more precise precipitation values. Aside from ...
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1answer
128 views

RFE raster images datum conflict

Im using ArcGIS 9.3. I've downloaded RFE images from FEWSNET. And im trying to load them on ArcMap, to clip them using Mozambique's shape. But as the RFE images related to Southern Africa come with ...
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1answer
133 views

Raster Dataset projection problem

I have a problem connected with my Raster Dataset projection. Two of its bands cannot be shown in some scale - only under 1:1500, when I use 'Zoom to raster resolution' option. Histograms for all 3 ...
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3answers
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Similarity between two raster maps

Having two raster maps as the examples below: We are interested in evaluating their similarities. As shown, they are not fully overlapping. We guess one way is to clip small one area from the ...
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1answer
198 views

GDAL reports no bands for a 12-band raster and no projection either

When opened in ArcGIS, the raster correctly unfolds 12 bands, but when I try to open it with GDAL through Python, it appears as a raster that has zero bands. Here is the code: import gdal from ...
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1answer
272 views

GRASS 7 - raster calculator “and”

I am struggling with one thing in the raster calculator in GRASS GIS 7: I want to create a raster_b from raster_a, with raster_a values between >=-0.15 and <=0.15. The raster containing values ...
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1answer
82 views

Which kind of grid format is this?

in a project I got some raster files with the following content (header and data are in one txt file): HOUR 17 MINUTES 30 YEAR 2012 MONTH 5 DAY 4 CITY Emilia;Bologna NROWS 99 NCOLS 156 ULXMAP ...
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1answer
207 views

QgsRasterLayer::identify() is missing after QGis upgrade to 2.0.1

My Ubuntu has just downloaded the latest version of QGis (1.8 -> 2.01), and my plugin failed with a plenty of bugs due to implemented changes in QGis API. I still can not figure out how do I replace ...
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0answers
86 views

grass region resolution error

I am working on a raster, but I can't set a correct region for it. In the Set region to match this raster map field, I select my raster map to change current region, but its resolution does not ...
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1answer
1k views

How to change the pixel value of a raster dataset which overlaps a polygon featured shapefile in ArcGIS

I have a raster data of 1992 and a 'shapefile' of Los Angeles county. I want to reclassify the pixel value of the raster data set to 'no data' or zero in the region where the raster and the ...
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2answers
91 views

v.what.rast trouble in GRASS GIS 6.4.2

I'm facing a problem using the v.what.rast comand. I'm trying to update the vector "canali" which represents some streams, with the slope value for every single point of the lines. The slope values ...
3
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1answer
461 views

Creating Contours from a Classified Raster - ArcGIS

I have a group of classified raster files, showing point densities at 3 intervals. I want to create contour lines based on this data at these same intervals. I'm guessing this should be fairly easy, ...
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4answers
361 views

How to compare areas in scanned historical land use maps

I am a relative beginner to using GIS, and am running QGIS 2.0.1 in Linux. I have two historical maps which I want to analyze, that show land use patterns in the same area at two different moments in ...
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2answers
208 views

In grass v.drape works with points but not lines

I got an elevation raster map which I interpolate from a point cloud with v.surf.bspline. Then I digitize a couple of points in a new vector layer. With v.drape I'm able to get a height from the ...
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1answer
165 views

create POV-Ray image from DEM-file in grass

I am working on r.out.pov Tool of grass 6.4 creating a POV-ray(beautiful 3D) image from an elevation raster. You can see this link for more information about 3D analysis of GRASS. r.out.pov manual ...
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0answers
197 views

How to create a raster dataset from a known decimal extent?

I have an input raster pInputRaster. I want to create a new raster dataset called pOutputRasterDS that is the same width, height and cellsize as my input raster dataset (I'm not worried about ...
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2answers
226 views

How to average a set of n rasters using gdal or other GRASS module? [duplicate]

I need to average a set of n rasters using gdal or some other GRASS module. What command exists for this purpose?
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1answer
500 views

Basic raster map questions

My bigger problem is to convert a raster map to polygons. I've found some questions that give info and I'm trying to use GRASS GIS as part of that. However, I'm having some basic problems and I can't ...
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3answers
414 views

Where to obtain free 15m ASTER image for New Mexico?

I am looking for a free Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) image that will let me to perform NDVI for the pilot crop health/soil moisture that can go as far back ...
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2answers
347 views

Read layer symbology class color with ArcPy

I am using ArcPy within ArcGIS 10.1 and attempting to read symbology from a *.lyr file created by a raster dataset within ArcMap. My goal is to be able read out the RGB (color) values assigned to the ...
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40 views

How to select raster layers for averaging based on values in another layer?

I wonder if anyone have some ideas about how to solve this geoprocessing situation: 1: I have a raster layer called mixlyr_apr (representing depth values) 2: I have a series of raster layers called: ...
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1answer
128 views

Is there limit of 5,000 rasters stored in folder by ArcGIS for Desktop?

I have a python script that creates batches of ~6,000 cost distance rasters. These rasters are intermediate data that will be summarized in another process. Output is stored in plain old folders. ...
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2answers
264 views

Are “gridded data” and “raster data” the same thing?

I'm working on a project that will involve both "raster data" (aerial imagery and DEMs) and "gridded data" which I understand to be other kinds of numerical measurements taken at grid points, and ...
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0answers
63 views

Copying an entire column between layers (tables)

I have a raster layer with probabilities as values and I process them using the Spatial Analyst extension. After the processing the values are modified, however I would like to also have the original ...
2
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1answer
2k views

Spatially join large raster to polygon shapefile

I have a large raster file with elevation data. From this raster, I would like to infer the average ruggedness for different geographic zones (like countries). I have the "countries shapefile" as a ...
3
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1answer
438 views

Area precipitation using IDW

I'm having the following problem with IDW automation. I have a catchment and several gauging stations measuring daily precipitation amounts. I would like to interpolate the precipitation amounts from ...
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2answers
129 views

Counting raster points within boundaries in another layer?

I know this question is similar to some out there, but I have tried all the 'solutions' and none of them are working for me. I am using the latest version of Qgis. I have a raster layer with ...
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1answer
207 views

ArcGIS raster data - Group statistics for classification

I'm trying to figure out how to classify a group of rasters. These can't be joined as they have overlaps which must be kept. I was wondering whether there's a way of obtaining grouped statistics - eg ...
2
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1answer
215 views

Efficiently check for equal adjacent values in raster calculator

I have a raster consisting of integer values in each cell. I want to check every adjacent cell in a 3x3 grid to see if any one of the adjacent cells has a value EQUAL to the center cell, and if so, ...
3
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1answer
372 views

Delete single raster from Raster Dataset

Is there any possibility to delete single raster previously loaded to a Raster Dataset?
3
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1answer
107 views

Cell values to No data

I need to set cell values in one raster to NoData based on another raster. Both rasters have the same extent and some cells overlap. For those cells that overlap I want to set them to NoData in ...
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1answer
183 views

GRASS GIS related issues! [closed]

(1) How to create a multiband raster from a set of single band rasters (except when somebody talks about doing a r.composite). I attempted creating a raster3D and it turned out that it is not ...
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1answer
77 views

Assigning an intersecting line length dependent value to a raster during polyline conversion

I am converting a road network polyline into raster format- my polyline shapefile has an exhaust emissions rate attribute which is in kg/km What I want to achieve is a raster that has (at say 5m ...
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2answers
215 views

Searching Open Source tool to load raster data into Oracle spatial

I'm looking for a tool to load raster data into oracle spatial. I found several commercial products but no open source tool. Is there anything available in the open source world?
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1answer
4k views

creating a buffer in a raster layer

I've got a raster layer separated into 3 zones, representative of marine park zones. What i'm trying to do is make it so that where zone 1 is adjacent to zone 3, there is a "buffer" between them, of ...
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0answers
211 views

How to perform Shapefile to Raster with ArcMap 10.1 while preserving resolution and values?

I am new to ArcMap and I would really appreciate some help. I want to create a new raster using a value in a column of a point shapefile. I have a point shapefile with points equally spaced and each ...
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0answers
182 views

Add Raster To Mosaic Dataset: Could not recommend a data source crawler for the specified input

I'm trying to add rasters (TIFF) to a Mosaic Dataset after adding some rasters, the process fails with the message. ERROR 999999: Error executing function Could not recommend a data source crawler ...
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1answer
2k views

R - Plotting shapefile with geographical (raster) data

Over the last few days I have been trying to plot a shapefile over data loaded into a data.frame within R. It should be a view of radar precipitation with an overlay of the country borders from a ...
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1answer
537 views

Polygon to raster without losing any polygons

I'm trying to convert polygons to raster. But the output raster dataset doesn't have polygons which went into as input data. I need all the date in the attribute to follow with to the raster dataset ...
3
votes
3answers
454 views

What DEMs does QGIS support? + DEM data sample

I am working on QGIS rasters. I want to know about DEM file formats supported by QGIS. I know that QGIS can read the GDAL supported formats. but what is GDAL supported format ? Does QGIS support the ...
2
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1answer
2k views

Convert 32 bit image to 8 bit image in QGIS

I want to convert my images from 32 bits to 8 bits. I'm using otb to calculate texture and the raster output is on 8 bits, I'm going to use this information as a layer stack for my multispectral image ...
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2answers
355 views

10 GB Raster Aerial Image in Quantum and POSTGIS

I have a problem... I have been successful in uploading the raster in postgis but when I access it through Qgis. it does not open even after several hours. I have 10GB aerial image raster and ...
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1answer
2k views

How to convert a bil image into grid in ArcGIS?

I've downloaded RFE data from FEWSNET. It's a compressed file which includes .bil files. Now i want to convert this ".bil image" into a grid to use the precipitation data in an area. I'm using ...
2
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1answer
392 views

Split single raster within multiple polygons

I have a raster ('slope') which content only one attribute in the table. On the other hand I have a feature which content several polygons (catchments) in the attributes table. I would like to obtain ...
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1answer
159 views

How can I turn QGIS into a simple hiking planner?

I'd like to try and turn QGIS into a simple hiking planner. I have found and worked out how to import OS raster mapping at the correct scale and how to add freehand vector lines to the mapping, which ...