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

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0answers
32 views

Change number of cells in raster using GDAL?

i have 5 raster files and i want to merge them to one file with exact 50x50 cells because i have an R script to process it later. I tried the ArcGIS function "mosaic to raster" but it delivers a ...
3
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1answer
242 views

ERROR 999999: Error executing function - Failed to execute (CopyRaster)

ERROR 999999: Error executing function Unexpected operation No spatial reference exists This is a fragment from my log report: ERROR 999999: Error executing function. Database user ...
1
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1answer
18 views

Merge large numbers of ascii files .asc in ArcGIS

I need to merge ~8k of .asc files into one big one. To convert each one into a raster first would take forever .. is there a possibility to convert multiple ascii files to raster in ArcGIS?
2
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1answer
335 views

ArcGIS model builder: How to reclassify 16,000+ rasters and do weighted sums on these rasters per year?

I've been trying to build a model in model builder (ArcGIS 10.1) which can do the following task: I have a folder full of ca. 16,000 raster files (.asc) representing mean temperatures for each day ...
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29 views

Deciding variables for image classification?

The results of an image classification may vary A LOT depending on the variables you use from the beginning. Number of classes, minimum class size, sample interval, atmospheric corrections, ...
4
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2answers
37 views

How to export a polygon based on elevations using a DTM or a DEM

I have a LiDAR generated DTM and a DEM (accurate to 10x10 feet). I am trying to export a polygon within a boundary which includes all elevations below a specific number. Seems like this should be ...
0
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1answer
41 views

C++ code and ArcGIS Button

I have some code in c++ that used gdal and process raster and create an output raster. I want to create a button in ArcGIS Desktop (using ArcObjects SDK 10.2 c#) and pass the raster layer to my c++ ...
1
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0answers
14 views

write python ndarray to raster

I think I understood the steps to write an array to a raster file using python. however it doesn't work in my case and I don't know why. I have an array that I want to write to a Geotiff with Swiss ...
0
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1answer
27 views

Converting satellite image into raster

I am (very) new to GIS in general. I would like to convert a satellite image of a province into raster, assigning each pixel its own data (i.e., a number and a name) based on its html color code. For ...
1
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0answers
11 views

Zonal statistics shifted

I am working with QGIS (newbie). I have a raster map with 0.5degrees resolution. I created a 0.5degrees width grid layer and I compute zonal statistics from the raster. My problem is that it seems to ...
1
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2answers
53 views

Exporting/Printing to PDF, raster basemap has stripe(s) or band(s)

Now that my map is pretty and perfect, I'm discovering that I cannot export it properly. I have tried Exporting the Map to PDF, PNG, TIFF, etc. I have tried various settings of image quality and DPI. ...
4
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2answers
43 views

IRasterLayer background transparency in C++ with ArcObjects 10.x .NET

I have a georeferenced IRasterLayer which is displaying data from a PPM file with no alpha channel. I am trying to specify a color which should be treated as transparent. In ArcMap it is possible to ...
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0answers
14 views

Derive individual land cover classes from .jpg map

I have a .jpg image which is land cover classification image with 9 classes. I want to extract raster image (.img file) which contains the same classes as .jpg image (9 classes too). Is there any tool ...
0
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0answers
9 views

Process a “Data Type: Mosaic” to calculate slope

I have a DTM stored as a Mosaic Data Type. I need to work with this DTM, calculate slope of it etc. however this is not possible in this format (Or does anyone have a Suggestion here?). I tried ...
2
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0answers
19 views

Comparing the use of GDAL to build raster pyramids or overviews versus Arcmap 10.1

I have a large set of imagery that I created a mosaic from in arcmap 10.1. I want to use GDAL to create the overviews because arcmap has issues building the pyramids and never seems to complete. I ...
0
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0answers
18 views

Changing datasource of a .lyr file results in empty layer with empty symbology (ArcObjects VB.NET)

I'm having a hard time adding my grid to the map and changing its symbology with an existing lyr file. I have found a great post by Neil Clemmons that explains this, but it doesn't work for me. I ...
0
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0answers
22 views

reproject satellite orbit values from irregular grid to regular grid

I have a ncdf file containing measurements covering a satellite orbit. The ncdf contains the corresponding latitude / longitude fields but they ar irregularly spaced. I tried rasterizing the values ...
4
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1answer
61 views

Free open satellite or other remote sensing data for night time?

I usually work with daytime satellite images to do some image classification (mostly Landsat data from the USGS EarthExplorer). Right now I'd like to check at some night time images to work on city ...
2
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3answers
404 views

Rasterize line shapefile

I'm trying to convert a line shapefile to a raster image at QGis, but my attempts have been unsuccessful. I've tried to use Raster/Conversion/Rasterize and SAGA/Grid - gridding/Shapes to grid, but to ...
0
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2answers
97 views

Change Data Source of Raster Layer Added to Map Display? Unexpected default

I have a script that I'm using to generate raster maps and automatically add them to the map display, but when they are added they are sourced to a temporary location. I use the same code for ...
2
votes
1answer
33 views

Mosaic Imagery using GDAL Edited

I have a couple of large sets of imagery I need to mosaic using GDAL. The sets are currently in tiff format with 18 tiles totaling about 20gb in size. I have attempted to mosaic using both the ...
0
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2answers
16 views

QGIS 2.10, csv points to vector grid

I have a series of point data from a .csv file that I would like to display as a heatmap raster, the .csv data have various attributes with them and I would like to adjust the color ramp based on ...
3
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3answers
753 views

How to change layer transparency without changing border lines?

I have a raster image of elevations. I have added a vector shapefile that contains local political divisions. I want to keep the elevation colors, but I want to keep the black lines representing the ...
0
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0answers
25 views

Referencing a raster by center coordinate

I'm concerned with producing mosaics from UAV thermal IR video frames. I exported several several frames containing the temperature values in a matrix (.csv). From camera specifications and flight ...
2
votes
1answer
406 views

USGS GeoTiff extent via GDAL

I have 2006 land cover GeoTiff from the USGS site (for a county in VA, USA). The projection is Albers Conical Equal Area Units. The download came with an HTML metadata file that tells me the geo ...
0
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1answer
20 views

How to use the hml <area> tag together with Openlayers 3 raster layers?

In order to include interaction to my Openlayer 3 raster layer, I would like to use something similar to the html <area> tag (http://www.w3schools.com/tags/tag_area.asp). The aim is to click on ...
0
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0answers
26 views

QGIS display wrong histogram statistics for float32 raster

While trying to display a float32 raster created with TauDEM, QGIS displays a min/max of 1,1 although the .aux.xml file contains the correct values. I am using QGIS 2.10.1 both on Windows 7 and Mac OS ...
0
votes
1answer
225 views

error invalid output extend in zonal statistic

i have a problem with arcmap10.2...i have a dtm(that now has dimension of the pixel 1000) and another raster whit the same resolution with the code of a specific area..what i want to do is calculate ...
10
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2answers
3k views

How to calculate average slope in a grid?

This is actually a two part question: Which methods are there to calculate average slope by unit (say km²) for a given area? Are there any special requirements on the data - like additional ...
2
votes
1answer
419 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 ...
0
votes
1answer
15 views

Segmentation and Classification in ERDAS

I have segmented an image inn erdas and will want to use it in a classification exercise, how do i proceed? My image is a low resolution 30m alos.
0
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1answer
42 views

count band numbers from multiband raster image

My raster image has 10 bands (10 bands are 10 year), cell values of each one are 1, 2, 3. One is negative anomaly, 2 is no change area, 3 is positive anomaly. Now I want to find how many years out of ...
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5answers
3k views

How to modify single Pixel values in QGIS?

I would like to modify a raster (pixel values) in QGIS. The plugins "value tools" can easily provide me with the value of the pixel of my raster. However I don't know how to modify it. I have found ...
0
votes
2answers
63 views

PostGIS polygon clip inaccurate using ST_Clip and ST_Union from tiled raster

I have a RGB raster tiled at 128x128 in PostGIS enabled database. I am trying to clip from the raster using a polygon as follows: SELECT ST_AsGDALRaster(rast,'GTiff') FROM ( ...
0
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0answers
7 views

Help with Raster files and Colour ramps [closed]

(A)I wonder if there is any general help with Raster files for QGIS? I am encountering some problems related to GRID files that have attribute tables attached in Arc but the attributes don't show in ...
0
votes
1answer
156 views

Combine overlapping rasters in gdal_calc.py, taking the maximum value from each pixel?

I want to combine 3 overlapping rasters to create 1 raster. Each have the same dimensions, resolution and CRS. I want to populate the new raster with the maximum value from each of the layers. ...
2
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4answers
334 views

How to convert a vector map to raster in Qgis?

I am creating a thematic map (vector data) with different classes. How to convert this vector map to a raster map, keeping the classification?
1
vote
1answer
115 views

How to use USGS Bulk Download on EC2 linux Server?

I am interesting in downloading Landsat 8 rasters to an Amazon EC2 instance and would like to know how to do it. I already install USGS Bulk Download but I do not know how to use it in terminal mode ...
2
votes
1answer
22 views

replace raster cell values with values in a .csv

I'm looking for a simple way to replace the value field in GRID format with values that I have in a csv. It would be much like doing a join, where the GRID and the csv have a FEATUREID and then ...
3
votes
3answers
1k views

How to extract X Y coordinates and RGB from pixels using python in QGIS?

I'm trying to white a Python plugin in QGIS (2.2) to get, for each pixel of a raster image, its X Y coordinates, as well as, its RGB (3 bands) values. At first I opened the raster file using: rlayer ...
0
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0answers
20 views

How to combine two different raster by replace its raster value at their overlap space? [duplicate]

I have two different raster data : First data : Second data How to combine those raster data? so the output data will be like this : Where the overlap space between First data and second data ...
2
votes
1answer
88 views

Zonal Statistics Freezing QGIS 2.2

Running on Windows; 8gb memory, 500gb HD, i5 cpu; Raster file: 250mb I am having a problem with zonal statistics advancing past 17%. I am trying to run statistics on a crop grown in certain counties. ...
2
votes
3answers
365 views

Geodjango read raster files

I am developing a web app in geodjango (django) framework but I need to import raster files. Is it possible a geodjango app read raster files from a directory? Thanks
0
votes
0answers
14 views

multiple attributes in csv file to raster

I have a several large comma separated text files each with multiple attributes. Each text file is about ~2.9 GB with 21 million lines. Each line contains X, Y, VALUE1, VALUE2, VALUE3, etc. The X and ...
1
vote
0answers
22 views

Is QGIS aspect analysis description mistaken?

I've been checking the Aspect analysis tool and several sources indicate that aspect is measured from 0 to 360, starting North and going counter-clockwise. Nevertheless, I've been testing it on ...
1
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0answers
15 views

Custom data source for GeoServer raster image

I'm working on a project where a custom binary data file contains latitude, longitude, and temperature data. I'm interested in creating a DataStoreFactory plugin to enable GeoServer to load this ...
0
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0answers
38 views

Aggregate / Calculate Cell Statistics >1000 Rasters

I'm looking for a tool/script that does simply what "Cell Statistics - Mean/Sum" in ArcGIS does but for more than 1000 Rasters (TIF) (I need to process ~10000 Raster at once). I'm not used to use ...
0
votes
1answer
163 views

How to fill holes/missing values in XYZ data / a DEM with QGIS?

I have equidistant XYZ point (text) data that I used to create a point grid. However, it's not perfect - there are some holes. I then created a DSM raster from it, which obviously has the holes too. ...
2
votes
2answers
64 views

How to sum pixel values of a floating point raster in ArcMap?

I have a floating point raster with values from 60 up to 95 (with decimals), it has 7077 pixels of 250x250m size. Is there a way to sum all pixel values of this raster? For example, if the raster had ...
2
votes
1answer
2k views

Creating raster map using Excel file and calculating averages?

I have thought about using ArcGIS to create a raster map of latitude/longitude (0 to 360 degrees) temperature data (in Excel format). This temperature data reflects the total amount of warming that ...