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

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Best way to store raster data with Java into Oracle spatial

I have a Java application that processes raster data. At the end of the process I plan to store the raster in oracle spatial. What is the best way to do this? I had a look at geotools but I did not ...
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311 views

Frequency of overlapping isochrones with map algebra in PostGIS

I have a table of polygons representing travel time isochrones on particular days. For each origin point, there are five isochrone geometries (stored in separate rows). For each origin point, I want ...
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54 views

Convert shapefile to multiple single-value TIFFs

I have a shapefile that is composed of multiple overlapping polygons that represent extent of habitats of certain species. Here is a 1 MB example of such file from International Union for the ...
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222 views

How to check for corrupted raster data?

I am working with thousands of tiled (2km x 2km) 4-band NAIP images. When I diced the images in Erdas, the program corrupted many of the tiles. The screenshot shows an example of one of the ...
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155 views

How can I identify lines that intersect a certain raster layer area?

How do I identify certain roads ( of a line shapefile) that intersect with a layer that is produced from the reclassify tool (for raster data)? I am trying to identify which roads specifically are in ...
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498 views

From polygon to continuous measure of diversity?

First of all; I have tried to find a similar question, without success. Maybe it's because I'm quite new to GIS and I don't really know what exactly I'm looking for. If someone points me to a similar ...
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31 views

Raster import problem

I have raster images (orthos) and feature layers in a GIS program (Global Mapper). When I import these files with the same CRS into QGIS they are literally 9000 miles apart and I cannot figure out ...
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348 views

QGIS: raster import “nan”

I've been importing raster files in ZMAP format using QGIS 2.4 and 2.6. Some of the files work fine but other files for some reason import a black image with nan as a default black and white value. ...
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221 views

Conversion of Polygon vector files to Raster GRID 8 bit unsigned integer

I am trying to convert a polygon shapefile layer into Raster GRID with 8 bits and which is unsigned integer. I managed to convert the shapefile in ArcGIS with the Arc Toolbox Conversion tools, but the ...
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82 views

How can one modify map service legend (specifically raster layer)?

I've got the raster layer in my map service, which in fact is created automatically by asynchronous GP service as its output result ("View results with a map service" option). The raster is symbolized ...
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158 views

Problem or ERROR in converting from raster to vector!

I wonder if anyone could help me out, i am kind of a beginner at QGIS. I´ve built a DEM for a project that i am developing than i´ve made the slope raster with the terrain analysis,it seemed that ...
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100 views

Convert Raster into Cell by Cell Table

I'm hoping to run some Python mathematics on a raster, outside of ArcGIS. It's important to have a cell by cell table for the analysis I want to run. I plan to store it in a python dictionary similar ...
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86 views

Subtracted 2 DTM layers to find the height of trees but all we have is the pixel values, can I convert this to height?

For a piece of coursework we have an aster layer that captures the tops of trees and a panorama layer that sees ground height (both are raster) so we have subtracted one from the other to get tree ...
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326 views

Scatter plot of two rasters in arcmap for intersecting cells

How do I make a scatterplot of two rasters in arcmap which will plot the two rasters' cell values of the same cell against each other (for every cell where they intersect). I need to first create a ...
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614 views

Combine raster values for overlapping cells of multiple rasters

How do I combine the values of cells for 3 rasters for cells where they overlap. I want the output raster to cover only the area of the overlap for the 3 rasters and the output cell values to be a sum ...
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56 views

How to create this raster?

I have three layers: building data (polygon) attributed with parking lot capacity on the road parking data (line), also contains parking space data car parks (polygon) includes parking space ...
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21 views

Converting a table to a raster for clipping

I have a series of tables (TAB files) that represent the calculated values for a corresponding .tif image. These tab files have the same number of rows and columns as pixels in the tif images. The ...
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39 views

Has anyone success using subset an image such as NAIP?

Has anyone any luck subsetting a small part out from NAIP? I'd like to hear your feedback on pros or cons on how to subset an image from NAIP despite they are in mrsid and their uncompressed file size ...
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69 views

QGIS Raster moving when Majority filter

I'm running QGIS 2.01 Dufour on Linux Mint. Data & project are WGS84. I'm trying to smooth a grid & following other posts here I've used the Majority filter. This is looking helpful, but the ...
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207 views

In qgis using python, how can I get multiple pixels from a raster based on a vector point file

I just started working with qgis, and for the life of me I cannot figure out how to solve this problem: I have several points of interest, these are stored in a shape file (just simple points). I ...
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2answers
510 views

How to calculate percentage of selected area from DEM?

I am working with elevation data and performed a local operation to convert it from meters to feet. I am interested in finding the area (expressed in percentage) that is above 4000 ft, but I have ...
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871 views

Save map in raster format from QGIS using compression

Is there a method to save a map in raster format from QGIS using compression? For exemple from "Export map" in ArcGIS there are many options to compress the images depending on the file type (tiff, ...
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344 views

Remove sections, defined by a line or polygon, from a raster in QGIS

(QGIS 2.6.0 on Windows.) I have created a raster layer of heights using the TIN interpolate function. I also have another raster layer with more accurate information on the height of particular areas ...
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46 views

Raster: how to locate cells having nodata

I am new to oracle spatial. I am using SDO_GEOR package's getNoData prcedure. the results are populated in following format. MDSYS.SDO_RANGE(MDSYS.SDO_RANGE(-32768,null)) My questions are: Is ...
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77 views

fit point with raster data figure out those points belong to, and add column and row to represent it in ArcGIS 10.2.2

I have an X-Y point data file, with which has latitude and longitude. I'd like to be fit it with the raster data, then add column and row data on the X-Y point data file. first i created the attribute ...
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121 views

Creating new raster based on spatial extent and classes of one raster and average of another using ArcMap?

I have a raster that is split into classes and I wanted to make a new raster with this raster's spatial extent and classes but displaying the average values from a different raster. I am not really ...
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352 views

QGIS 2.4.0 Setting raster layer to singlebandpseudocolor using minimum and maximum raster values

I am using QGIS Chugiak 2.4.0, and I have some code in which I want to: Add raster layer to map canvas Look for the minimum and maximum raster value Apply singleband pseudocolor render type for the ...
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801 views

How to decide how to “stretch” raster imagery?

I have to symbolize a digital elevation model. ArcMap offers many different setting for stretching the symbology which all give widely different results. Some stretch methods symbolize the data so ...
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573 views

What effect does standard deviation have on the display of DEM rasters?

I need to explain why ArcGIS offers the function "standard deviation" when symbolizing rasters with the Stretch method. The Standard Deviation is a measure of how spread out numbers are and is ...
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880 views

Using raster to clip vector data

I have high res raster data covering 2million km sq, with a field where each cell has a value from 0 to 100. I need to create a "mask" using the cells with a value over 12 in that field. I then need ...
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2answers
366 views

merging raster aerials in QGIS issue

I follow the instructions here very closely and yet every time QGIS gets caught in a loop. It takes a few small rasters totally less than 100mb and creates HUGE gb files and will not stop until python....
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How can I join all data of two raster datasets in ArcMap 10.2?

I have two raster datasets in ArcMap10.2. One is displaying rails and one that is displaying a 100m Buffer to both sides of it. My cellsize is 100x100m. What I want is to combine the rails AND the ...
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92 views

Modifying raster values in a zone with a math expression

I'm currently doing an SIG project with the goal of calculating groundwater volumes in chalk and silex residuals aquifers. I have point data of underground water, chalk roof, and floor elevations, as ...
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21 views

QGIS Extract elevation data only for one country [duplicate]

I have a map built with a shapefile for country contours and a raster from .hgt files with elevation representation. How can I only select the area corresponding to the country? I found some thing ...
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37 views

Web Server/Technology to work with Raster-Imagery Data

I am in the process of designing a web application which will allow the end users to load raster imagery data (size range from 300 MB to 500 MB) as a back ground map and a corresponding OLD JPEG image ...
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181 views

Arcpy reclassify all values to same number

Using ArcGIS 10.1 and arcpy, is there a way to reclassify all values of a raster file to the same value (leaving NoData Values as "NoData")? Lets assume that I have no way of knowing what the actual (...
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203 views

How to narrow raster features to single cell width?

Are there any tools or existing workflow which convert raster features (such as roads, rivers, electric lines etc.) which are (or can be) multiple cells wide to a single cell widht (i.e, center line). ...
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168 views

Creating a Raster of Road Distance to Point

I am using QGIS 2.6. This question is in two related parts: I'm trying to create a raster of travel time from one point to another point travelling via the road system. Each raster pixel will roughly ...
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138 views

QGIS raster symbology problem in 2.6

With the new 2.6 QGIS version I often have problems with raster colors. For some reason certain pixels do not display initially, but if I move the raster a little spatially they show up.
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119 views

Defining polygons based on thickness maps using ArcGIS for Desktop? [closed]

I want to find and create polygons that demarcates three different inflection points in a thickness raster: where the thickness start to increase, where the thickness is at its max and where it starts ...
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94 views

area elevation distribution with QGIS

I have a raster DEM and a polygon covering a part of it. I need an area-elevation distribution (i.e. how many m2 are in which elevation interval). 20m intervals will be fine. I cant figure it out.
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33 views

Percentage of a polygon at, or less than, a specific height (supplied by a raster)

I am using QGIS to process some LIDAR data. I need to be able to define the area of a pond with respect to its depth (i.e it is 100m^2 at 32mAOD and 500m^2 at 33mAOD). Is there a way of finding the ...
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608 views

Prepare raster data for wms using geoserver!

I have some orthophoto of different resolution (urban 8cm pixel, hill 20cm pixel, mountain 35 cm pixel) which cover an area of 28000 km2. Those are in jpg format, already georeferenced. I need to ...
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1k views

Is there a standard for the coordinates of pixels in georeferenced rasters ?

We are working with different raster datasets, and the pixel coordinates are either stored at the center of the pixel or at one corner. The information is usually provided in the metadata, but ...
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Do rasters other than “north up” exist in the wild?

"North-up" (as I understand it) refers to raster images stored with the northerly direction at top, and each subsequent line of pixels is a bit farther southward. Rasters' georeferencing metadata ...
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40 views

Will Processing without a Spatial Reference cause Issues?

I was given a bunch of ASCII files that I needed to convert to raster and then create maps from. For some maps I had to do a simple difference calculation between two rasters (did this in ArcMap). ...
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162 views

Only run r.neighbors if cell meets criteria

This is my first time using GRASS to work with Rasters, so please excuse my lack of knowledge on the subject. I want to run the GRASS r.neighbors function on cells that meet a specific criteria, ...
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717 views

Apply Symbology to Rasters using Arcpy Script

I have an ArcPy script to apply the symbology of one raster layer to all of the raster layers in the table of contents. I have used this script before with feature layers instead of raster layers, and ...
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43 views

Adding images to raster field in batch

So I've got about 300 records in an attribute table that each need an image to go with them. I've created a raster field on the table, and I've got all the needed images as rasters in the same GDB. I'...
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Raster overview hierarchy in WMS [duplicate]

I have rasters with low resolution which covers the whole area, and in certain spots i have some rasters with higher resolution which covers small parts of the same are covered by the lower raster ...