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

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2k views

Digital Number (DN) on satellite imagery? [closed]

How would I know if any of the satellite imagery (Landsat, ASTER, Quickbird and so on) have DN or Digital Numbers such as integer or uninteger on its pixel. I download from the USGS EarthExplorer and ...
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1answer
83 views

Postgis Raster merge geometry

I have a raster table and a geometry table in postgis. My goal is to create a single raster merging elements from both:- WITH geom_raster AS ( SELECT wkb_geometry, ST_AsRaster(wkb_geometry, ...
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0answers
124 views

How to create cost surface for least cost water transport analysis?

I am working on a project to derive least cost pathways between sites by dug out canoe travel. Has anyone worked on a similar project or found a function like the Tobler hiking function that can be ...
2
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0answers
76 views

Does converting polygon to raster generate more accurate results from the Zonal Statistics in Arcgis 10.2

I have heard the following for Arcgis 9.1 and wonder whether it is still an issue in Arcgis 10.2. If so, should I convert the polygon into raster before dissolve or convert the dissolved polygon ...
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0answers
88 views

Fill holes with an area bigger of a specific value in a raster coverage

I want to fill some areas of a raster coverage with a value of my choice. Those areas now contain NODATA values. So, they look like holes in my coverage. I know I could use r.clump function of GRASS, ...
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0answers
110 views

ArcGIS 9.2 - Problem importing raster into geodatabase

When I try to import a raster (jpg or tiff) into a file geodatabase using ArcCatalog, MS Picture Manager opens and tries (unsuccessfully) to open RasterConversion.py located in my ArcGIS program files ...
2
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1answer
91 views

Make a ground mask raster with the Greater Than tool

I'm trying to see if I can replicate the Esri solar suitability site example from this article. I fail on the creation of the binary ground raster. I have made a Bare Earth raster from LiDAR ground ...
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1answer
2k views

Raster Calculator Workaround in Arcpy for Suitabiliy Analysis

This is my first attempt at a complex stand alone python code. I am self teaching the arcpy module, well at least attempting to. I am having a great deal of difficulty getting my site suitability ...
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1answer
146 views

Converting GeoTIFF into non-compressed format for 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 ...
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0answers
39 views

Analyse effect of groups on raster maps

I work with a mechanistic model that uses climate data to simulate some specific output for different time steps and spatial locations. Now I want to investigate the effect of different climate data ...
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1answer
53 views

Raster To Ascii cmd-line tool

Where can I find a tool like ArcGis: Raster_to_ASCII Provided that the tool MUST be accessible through command line interface.
4
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1answer
384 views

How to automatically check for lidar flight line overlaps?

I have a series of lidar-based raster products created via FUSION. Since I am working with low density lidar data, many of the raster images show significant striping where lidar returns overlap on ...
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1answer
235 views

How to remove thin lines and small points from qgis raster

I want to digitize the roads of a raster map to vector format using QGIS and GDAL preferably. By using the Raster Calculator I have been able to extract the roads and contour-lines from the raster to ...
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1answer
325 views

How can I create an animation with raster data in qgis?

I have 4 raster images showing different coniditions of air flow distribution at different times. I'd like to create an animation to show the change from image 1 to image 4. How can I do this? I tried ...
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1answer
264 views

Exporting .tif from referenced mosaic dataset does not use functions in raster dataset

Very frustrating little issue in ArcGIS 10.1 -- I have a referenced mosaic dataset of terrain data that has a series of functions inserted (slope and several iterations of a statistics function to ...
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0answers
50 views

Calculating raster values from center to edges to represent normal distribution

Edit for simplification/clarification: What I want to do is take a raster and calculate cell values from center to edges such that the center has an arbitrarily determined high value which decreases ...
2
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3answers
540 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
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3answers
539 views

QGIS Mosaicing with null values in images

I have a set of landuse landcover data which needs to be mosaiced. Whenever i try using QGIS Raster>miscellenous>merge tool. giving no datavalue as '0', it returns either (A) ' Traceback (most ...
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1answer
40 views

How do you set sea level elevation to white in terrain analysis?

I have ASTER files I am working with to create a shaded relief background for some other vector shapefiles. In experimenting with different color-elevation options, I am unable to have the Terrain ...
0
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1answer
303 views

Weighted Overlay with “nodata” cells

I´m currently conducting a suitability analysis with the weighted overlay function. One relevant criteria is the proximity to highways. If the wind turbine is located up to 300 m away from the ...
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1answer
75 views

Show raster data in WEB

I have downloaded Landsat8 image and use matlab to processing temperature and vegetation. Then I insert data into PostGIS. I used QGIS to display the results but i want show in web. How to display the ...
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0answers
370 views

Error: .asc is not a supported raster data source

I am new using QGIS and struggling with this error "...... .asc is not a supported raster data source" when trying to add a ."asc" file as a raster. I downloaded the files from ...
0
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1answer
73 views

Is there any method to choose the value of each pixel according to land cover

I have 2 images; one is land cover image (imgA) and monthly mean temperature image (imgB). I'd like to choose value of each pixel from imgB corresponding to imgA. WhaT I expected is each pixel of ...
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1answer
316 views

extract shapefile attributes from raster colors

I have two layers: a shapefile with states and counties (shp) a raster file (with colors and some text and borders, but not a perfect map) (tiff) I want to use the colors in the raster file to ...
4
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1answer
496 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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0answers
258 views

Problem with polygon overlay in raster stats using gdal

I am using the raster_stats module in python to calculate the mean carbon value for different sets of polygons. Here is the code that I am using: africa_sat = ...
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2answers
341 views

Reading a raster map cells values in C#?

Suppose I have a raster map file (TIFF, TGA, JNG... etc) loaded with geo-info manifested by the cells values. I need to read the values of the raster map cells "programatically" in a C# program. P.S: ...
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1answer
4k views

How can I save and re-apply symbology properties for a classified raster in ArcMap 10.2?

I have a classified raster which has the desired symbology configured in ArcMap, and I want to apply this symbology to other similar rasters. So I use the Save option on the Symbology tab, intending ...
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0answers
234 views

How to create a circle vector layer with 12 sectors with Python and to save average value of underlying raster in each sector?

Hi I am writing a code with Python 2.7 using Arcpy 10.1 and I guess I am doing stuck with a silly problem that lies under my eyes. I have created a grid of points (with "Create fishnet" function) over ...
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1answer
442 views

Eliminate 0 Values From Raster

Arcgis 10.2 I currently have a raster file that I want to turn into a set of polygons. This will help me to create specific buffers around certain points. The extent of my values are 0, and 1. When I ...
2
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0answers
113 views

Comparing/Correlating NDVI Rasters with other index Raster

So, I've created two rasters. One for NDVI and one for another index for surface water from the same orthorectified World-View 2 image. I can visually see how the indexes are inversely proportional. ...
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3answers
3k 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 ...
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0answers
178 views

Raster slightly displaced after exporting from PostGIS database

With the following queries I've exported a raster (GTiff) from my postgis database: 1.Creating a large object: WITH buffer AS ( SELECT id, ST_Buffer(geom,50) AS geom FROM ...
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1answer
80 views

How to export a IDW raster while keeping the search radius data

I want to export my IDW rasters that I made in ArcGIS to QGIS, however when I export my raster, the values are there but are no longer displayed. They are stored within each cell and are not ...
0
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1answer
948 views

How to translate .bil files in a batch mode with QGIS?

I have some .bil files that I would like to convert into ASCII Gridded XYZ format files. It seems to work well with the Raster>Translate tool of QGIS when I process one file at a time. But I would ...
2
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0answers
512 views

How to open a raw binary raster in QGIS or R

I have a raw binary raster without a file ending, and no header file. I would like to open this in either QGIS or R and then convert to geotiff, but opening it seems to be a challenge. Here is a ...
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0answers
269 views

Is it possible to apply affine transformation (translation) to raster image?

Is it possible to move/translate a raster image in QGIS 2.2 (without using georeferencer) just like it can be done with a shapefile ? If not, alternatively can this be done with ArcGis?
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1answer
82 views

Calculate the coordinates upper right corner from the center [closed]

How do i calculate the coordinates upper right corner from the coordinates of center? if there's an example that would be really helpful.
2
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2answers
516 views

Create a common scale for different raster layers in GRASS, SAGA or QGIS

I have a number of layers that represent the temperature variability of the water in a lake. They have been generated trough interpolation and have different values as they represent temperatures ...
0
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1answer
155 views

change spatial resolution

I have two types of image, one of them is a TRMM image with 0.25 degree cells and the other one is a MODIS image with 1 km spatial resolution. How can I change my TRMM image resolution to 1 km ...
3
votes
1answer
2k views

Re-project raster image from Mercator to Equirectangular

I have a raster image of the world map in Mercator projection, square 1:1 format. I want transform the image into an Equirectangular projection accurately. I assumed from my research that GDAL would ...
0
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0answers
317 views

Make a raster with pixel scale 100 by 100 meter with gdal_rasterize

I'm asking here, because, I've got great results last time. Here it is the next of my adventure with gdal_rasterize, I want to make a raster picture where each pixel correspond to a square of 100 by ...
3
votes
1answer
163 views

Why is Mosaic or Mosaic To New Image causing a 1-pixel gap between adjacent images?

I have a series of adjacent PNG images, and I'm trying to merge/mosaic them into a single seamless image. The images have clean "cuts" between them, with no overlaps. However, when I use either the ...
0
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2answers
644 views

How to display a raster using Javascript API

It's all a proof of concept for myself and my learning but I have definitely hit a brick wall here! Here's what I've done and can get to work. I have written a Python script that: Sets its ...
0
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1answer
91 views

Associate points with polygon QGIS 2.2

I want to associate a point layer with a polygon layer so that I can do zonal statistics. In the image below, the polygon layer represents roughly the metro area of a certain city. The point ...
2
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2answers
655 views

Conversion of point grid to a raster with open source tools (Gdal, QGIS …)

I'm looking to do something which seem simple to me, but I haven't found a solution since 2 days I looked for. I've got a Postgis DB with lot of points (WGS84) spaced of 100 meters which cover a ...
2
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0answers
148 views

How to normalize multiple PNG rasters with differing colormaps

I have a series of adjacent rasters which comprise a digital elevation model. Unfortunately they have been given to me as PNG files, rather than Esri Grids. The only key that I have to the actual ...
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1answer
738 views

I'm converting a raster to TIN and a large section of it didn't convert properly (ArcGIS 10)

I've got a DEM for a pretty large area and I need to create a TIN. I'm using 3D Analyst Tools > Conversion > Raster to TIN. The process runs without any error messages, but a large section of the TIN ...
2
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2answers
58 views

Delete numerous NoData rasters from database

I've got >1000 rasters in a folder with about 10% containing no data. I'm looking for a method, preferably through ArcGIS (also open to QGIS, GDAL, etc.), to run through the folder and delete all of ...
2
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1answer
1k views

Mosaic Aerial Photography Tiles to a Seamless Raster

I've got about 6 different Aerial Photography datasets I am managing at the moment. All of them are made up of tiles covering a large area. Some of these datasets contain up to 2000 tiles. All the ...