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

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Set NoData values to -999 in ArcGIS 10.3

I know how to set a value to NoData using SetNull, but how about the opposite? If I had cloud pixels in a Landsat scene that are currently set to NoData and I want to set them to -999 (an extreme ...
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9 views

Tracing a raster layer in QGIS [duplicate]

I have a basic map I would like to trace into vector form in QGIS. The map is just a JPEG and has no coordinate reference data. Whenever I import it into QGIS, it ends up as a tiny speck at 0,0. How ...
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19 views

How to calculate the raster statistics with polygon layer using numpy and scipy in python?

I have used zonal statistics from processing to calculate the raster statastics with polygon layer. processing.runalg('qgis:zonalstatistics', rlayersource, 1, vlayer, None, True, Path) But this is ...
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21 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?
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22 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 ...
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28 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 ...
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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 ...
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35 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, ...
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18 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 ...
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37 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 ...
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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 ...
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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 ...
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28 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 ...
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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 ...
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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 ...
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1answer
66 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 ...
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2answers
39 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 ...
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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 ...
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1answer
24 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 ...
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37 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 ...
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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 ...
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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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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.
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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 ...
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42 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++ ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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2answers
64 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 ( ...
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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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46 views

Changing raster calculation values - shorten this script?

i'm doing something quite straightforward regarding raster algebra but am struggling either to find the correct function or make a function work correctly; Basically I have 2 rasters, representing ...
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42 views

Converting large rasters to NumPy

I have a geodatabase that contains a large number of raster datasets - there are two rasters for each country in the world, and they are very large, in some cases up to 3GB per raster dataset. I ...
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16 views

Reclassifiy raster in R [duplicate]

I have a raster file which has been classified from 1 to 255. I have to reclassify into binary form where 1 to 11 must be classified as 1 and the rest must be 0.How would I be able to do it in R. My ...
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24 views

export several rasters from grass

I'd like to export 127 raster files from grass to .tif in one operation. I already stumbled over this post How to batch export using r.out.gdal command in GRASS but it doesn't work (I don't even know ...
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1answer
29 views

Rasterization of point vector in QGis: how to align the resulting raster to an existing one?

I have a point shapefile, with no associated .prj file, that I have to rasterize. Each point should be transformed into a pixel of 30x30 size aligned to the pixels of a Landsat image (the point file ...
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18 views

Is QGIS Server working like this?

On CentOS 7 I have QGIS Server and QGIS Desktop installed. In QGIS Desktop I created a project with raster and vector data and saved it in a ".qgs" file. Then I copied the file in ...
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23 views

QGIS GRASS raster to GeoTiff

First of all: Windows 8.1 QGIS 2.8.2 Wien My problem is that I used the GRASS module r.watershed to delineate watersheds and get flows with a DEM. It worked fine so everything is OK so far. But ...
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30 views

Using Terrain Profile plugin with an interpolated raster

I am very new to QGIS and the goal of this exercise is to view an elevation profile of a river from a set of discrete points taken from surveying records. Steps taken: A vector layer was created ...
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20 views

Subset moving window when using focal on raster in R

I have a classified Landsat image, and I'd like to pass a filter over it converting certain cells to 0. For some categories, I'd like to set cells to 0 unless an entire 7x7 window contains only that ...
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18 views

Achieving consistent RGB Composite Settings using ArcPy?

Does anyone know if there is an arcpy tool so that when I bring in raster imagery (Specifically Landsat) into ArcMap it will automatically adjust the settings of the RGB composite? I know under ...
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27 views

Combining several mask rasters to obtain one single mask with binary values

I have a series of separate rasters which represent the cloud cover over the same area but in different months. Each raster has 2 values: nan for "no cloud" and 255 for "cloud". What i want to do is ...
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39 views

How to find details to NASA's "Earth’s city lights” images

I am currently working with these images. To find the resolution etc. is simple. But how to find in what units are pixel values? Or any additional details for "how to cite" these images?
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216 views

Benefits of *.las vs *.xyz or *.ascii when working with LiDAR in ArcGIS for Desktop?

From time to time, we use lidar data for modelling in arcgis. Previously, we would be supplied either an .xyz or .ascii of the data, but more recently, we are also being provided .las files in ...
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Expanding raster extent with ArcPy?

How can i expand extent of a raster image with Python as the image shown in below. I have the coordinate information of a raster image such as Xmin Ymin Xmax Ymax,how can i expand its extent based on ...
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Generating polygons based on georefernced Raster image

I have an aerial imagery of a crop field, each of these polygon-looking-group-of-crops-together is called plot. I need to make a polygon shapefile that overlays on top of these plots in the image. I ...
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Segmentation fault while writing an output raster by blocks with rasterio

With the answer on my previous question, I was able to set up reading a raster by blocks. I did some computation and now I try to write the result into another raster. However, the program fails with ...
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43 views

Create a raster with ranges from another raster

I have a raster that contains values ranging from 1-180. I am looking for a way to create a new raster where if the values of a cell in the original raster is between 1-10 the new raster cell gets the ...
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22 views

Project Raster: Resampling

Is this (optional) resampling technique in the Project Raster tool only being used if changing the grid resolution (cell size)? Or should I always select bilinear (or cubic) for continuous data even ...