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

learn more… | top users | synonyms

7
votes
1answer
378 views

How to store Large Raster Images of Equipotential Surface Generation Using Monte Carlo Simulation?

I have a large (1GB+) raster that I am using as the base for the generation of an equipotential surface. This is to assess the accuracy of DEMs derived from another source. In situ observation is ...
6
votes
1answer
153 views

Automate Exporting of Rasters Using Renderer in ArcGIS

It is possible to export rasters in ArcMap by right clicking the layer-> Data-> Export: You can then click 'Use Renderer' check box to ensure the image you export uses the current ...
5
votes
1answer
133 views

Optimizing Python GDAL ReadAsArray

I am using the GDAL ReadAsArray method to work with raster data using numpy (specifically reclassification). As my rasters are large, I process the arrays in blocks, iterating though each block and ...
5
votes
1answer
979 views

How to force RGB in a raster in QGIS?

I have rasters in 1 band 64bits float that represent real data values and for which I can set min and max using the stretch to min and max option in QGIS. I would like to convert these rasters to RGB ...
4
votes
1answer
39 views

Grid size of a Digital Elevation Model developed from topographic surveyed elevation contour line?

I have generated a Digital Elevation Model from elevation contour line. I got these elevation contour line at 20 cm interval from DGPS survey. What would be the grid size of generated DEM in "m". ...
4
votes
1answer
21 views

Conditional Combine Rasters and Track which Raster pixel used

I have 6 rasters with pixel values ranging from 0 to 1. I want to extract the highest pixel values from each raster to create a new raster, but also have a way to show which raster the highest value ...
4
votes
1answer
49 views

Is it possible to locate a specific marker point on a raster using python and use that location for georeferencing

I have several scans of the same map, which I would like to georeference. I can not use arcpy.WarpFromFile_management(...) as the rasters are slightly different due to scanning. Is there a ...
4
votes
1answer
112 views

Does gdal_calc only support 26 input raster files at a time?

In gdal_calc.py, input files are specified with letters A-Z. Here are two files, input.tif and input2.tif, being averaged into result.tif: gdal_calc.py -A input.tif -B input2.tif ...
4
votes
1answer
169 views

Iterate through rasters in subfolders using Model Builder

I have a directory folder of precipitation data; within this folder are subfolders for years 1901-2014. In each of these subfolders are 12 .asc grid files; each file represents a month of the year ...
4
votes
1answer
505 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 ...
3
votes
1answer
45 views

QGIS Has Rendering Error on JP2000 Raster. Works in ArcGIS

I've got a large .jp2 raster file that was created using 'Mosaic to New Raster' in ArcGIS. I'm trying to open it in QGIS 2.8.6 (I've tried 2.8.14 as well) and am getting a vertical line that won't ...
3
votes
1answer
65 views

Build a table with columns of raster values from multiple raster datasets, using Python, GDAL, or PyQGIS?

I have a series of raster datasets, clipped to the same extent, with matching cell resolutions, each of which represent land surface temperatures (LST) captured by the MODIS sensor. Each raster ...
3
votes
1answer
36 views

Displaying Raster Source Information

I have a large number of raster files I'm working on. I need to figure out how each of the files was processed from. I have a composite land cover map and would like to view the file names and ...
3
votes
1answer
79 views

What is faster - a matrix, raster or a dataframe?

I have rasters over which I am performing mathematical operations. For example, where I need to calculate flow distance or distance between two grid points. What format is generally considered faster ...
3
votes
1answer
43 views

Help with Rastercalculator - Filter areas with a certain height difference

I'm struggeling a little bit with the rastercalculator tool of QGIS. At the moment I am working with a DSM and a DTM. My aim is to filter all wind turbines out of the DSM and replace it with the ...
3
votes
1answer
291 views

Split raster into tiles

I have a raster that needs to be split into tiles (each tile a new raster). I have a Shape file with multiple polygons (these polygons are how I want the raster split). I have Gdal and QGIS. Any ...
3
votes
1answer
93 views

Storing a coverage in a JDBC database

There is another question about raster data for GeoServer. Conditions: - PostGIS 2.0.3 and PostgreSQl 9.2. - I followed: ...
3
votes
1answer
109 views

Least cost path with one-off cost for highest elevation

I'm trying to write a script to calculate the least cost path between two cells on a raster. I'm reasonably familiar with the approaches used by tools such as GRASS GIS's r.cost and ArcGIS's ...
3
votes
1answer
179 views

Export Stretch Function values - Arcpy

I'm looking for a way to export Stretch Function values from images that’s stored in a Mosaic dataset. Not values from the whole set, but specific stretch functions per image. The set is stored in ...
3
votes
1answer
464 views

How to count and rasterize polygon overlaps in QGIS?

I have a large number of polygons that are overlapping. I'd like to create a heat map and plan on using raster calculation to do this. My plan: to give each polygon a raster value of 1, and adding ...
3
votes
1answer
86 views

How to always see all band values with Identify Features of QGIS?

Does anyone know if it is possible to get the Identify Features tool in QGIS to show the band values for all the layers shown in the results window? To clarify, whilst I have several bands "showing" ...
3
votes
1answer
381 views

An error in raster calculator in Arcgis

I wrote and ran this formula in raster calculator in ARCGIS. But the following error gets me into trouble. Does anyone have a suggestion to overcome this? Here is the formula I wrote and the error ...
2
votes
1answer
26 views

Convert/display grayscale image as RGB

i want to display raster images using a color palette in a leaflet map. The images are tiled (gdal2tiles) from a single .tif to multiple .png files with values from 0 to 100. I add the image using ...
2
votes
1answer
28 views

Failed DEM via Natural Neighbor in QGIS 2.14.2-Essen

Following the indications of Monde Geospatial (https://www.youtube.com/watch?v=bLbY3iMBW-A) I created a CSV file with the altitudinal data (Google Earth) for 2182 total points and imported it into ...
2
votes
1answer
45 views

Aerial picture - how can I extract water drainages on a crop (to vectorize them)

I have a RGB aerial picture of an agricultural crop. The drainages (hundreds of them) can be barely seen because they a very slightly greener then the surrounding crop area (picture is from April). ...
2
votes
1answer
39 views

How can I calculate the percent of a raster cell covered by a polygon?

First, I am going to try and intersect a raster and a polygon shapefile. I'm not 100% sure how to do this (or if I need to do this for the next step), so if you have any suggestions please let me ...
2
votes
1answer
32 views

Raster rotation on QGIS

How can I rotate a raster layer (global land-mass) to make the 180 deg longitude the center of the map (using QGIS)? 'rotate' function in R is simple but not accurate. Raster has 'longlat' projection ...
2
votes
1answer
35 views

Determining hardware requirements for mosaic dataset operation to work properly?

I've been building mosaic datasets in ArcGIS, but have been having mixed results depending largely on the number of cores on the computer being used to build the mosaic dataset. For example, on a ...
2
votes
1answer
26 views

Mouse-over raster surface to stream values to text file ArcGIS

This is a weird one. I have a user who wants to add a statistical surface to ArcMap and then mouse-over the raster surface and stream those values (z) to a text file. MouseTips can show underlying ...
2
votes
1answer
44 views

ArcMAP / R: Convert raster pixels to Long and Lat

I have downloaded a raster, which has the following information. Item Data Date 2015-01-03 00:00:00 Product cold partial sst Satellite NOAA-18 Direction Unknown Dimension 1596 x 1617 BPP ...
2
votes
1answer
43 views

How do you extract the mean fire frequency (raster) for each point within a given buffer size using R?

I am trying to extract fire data (mean and max fire frequency) for each point within a given buffer size (250m) around multiple points. Currently, my point data is in Lat and Long. For the raster ...
2
votes
1answer
13 views

How to extract values from multiple raster dataset from a location point in one single dbf?

Suppose I have 250 raster and my only concern is just a single point. The raster is arranged by ascending date. So if I extract a point value based on the order into one single file then I can graph ...
2
votes
1answer
26 views

Create MosaicDataset with 12 Bits

I'm using ArcGIS 10.3.1, and I want to create a mosaic dataset, but my rasters are in 12 bits, and a mosaic doesn't have this option. What can I do?
2
votes
1answer
36 views

Why is ArcMap reverting 4-band raster settings?

ArcMap keeps redrawing my 4 band false colour image in standard 3 colour bands. As you can see below I have my 4 band data set to auto display as (4,1,2 - infrared, red, green). When I bring in an ...
2
votes
1answer
83 views

Raster statistics for polygon areas PostGIS

I'm trying to get zonal raster statistics for each polygon area. I have used the following method from this site: SELECT bufid, (ST_SummaryStatsAgg(ST_Clip(rast, geom, true))).* FROM rasttable, ...
2
votes
1answer
48 views

Combining two euclidean distance rasters in Raster Calculator

I have two euclidean disance rasters and would like to combine them for use in a multi criteria evaluation. Could anyone advise me on the syntax to use within Raster Calculator (ArcGIS 10.3.1)? There ...
2
votes
1answer
75 views

What is limit to physical number of raster TIFFS that can be placed in QGIS?

Can anyone please let me know if there is a limit to the physical number of raster TIFFS that can be placed in QGIS? I am trying to bring in a large number of StreetView tiffs from the Ordnance ...
2
votes
1answer
54 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 ...
2
votes
1answer
30 views

Mosaic rasterstacks based on minimum of certain layer?

I am trying to mosaic 42 remote sensing rasterstacks (with 250 bands) based on the criterion that in overlapping areas, the pixel should be taken that has the most nadir viewing angle Beside my ...
2
votes
1answer
792 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
1answer
125 views

Is there a better way to convert Raster to Point data? Don't need one point for every cell

I need to convert raster data to point data so I can use the points for interpolation via kriging. My problem is that my resolution is 5 ft and I'm working on a whole city. The data I am converting ...
0
votes
0answers
60 views

Problem with Georeferencer not scaling TIFcorrectly

I am trying to use QGIS and the Georeferencer to digitize paper maps but I am unable to get the raster to rotate afte I pick my control points. Below is a brief outline of the steps I used to ...
0
votes
0answers
35 views

QGIS: Unable to project raster layers correctly on a Toshiba Tecra 64# Win7

I know how to project a raster, I can do it on other machines. On this particular machine the raster loads but are no where near the correct position as if the datum is on another planet.
0
votes
0answers
186 views

Display raster outlines

I guess mine is a very simple task, however I don't know how to solve it. I m trying to display the outlines of a raster created from a polygon shp. What I would like to come up with is an image where ...
0
votes
0answers
147 views

Searching Pixel Location (idrisi) on Another GIS

I'm Searching similar command Pixel Location (like idrisi) on Another GIS, I, need create raster file with values ​​lat, long by separately... Update: I need a raster file where the value of each ...
0
votes
0answers
1k views

How to resample a raster in QGIS?

I've got a boundary file that I would like to resample the raster file from a 30m grid to a 10m grid inside the boundary file. When I try and do it in Qgis or Grass all I get is one big raster cube ...
0
votes
0answers
216 views

Calculate optimal paths between different points

How can I calculate all the possible paths between a group of points, taking into consideration the SRTM and the Slope ? I am trying to do this in ArcGIS, my dataset is a group of points (shape ...
0
votes
0answers
239 views

QGIS Georeferencer and Coordinate Systems

I'm having an issue with Ubuntu and Windows versions of QGIS where the georeferencer does not properly assign the coordinate system to the output raster. When I assign the output CRS to 'EPSG:900913 ...
0
votes
0answers
272 views

QGIS Invalid Data Source in raster calculator

I just installed QGIS and am new to it. I want to use the raster calculator, but after assigning a name to the output layer QGIS tells me "Invalid Data Source" and "filename.tif is not a valid or ...
0
votes
0answers
207 views

SAGA grid VRT, file how to apply a LUT?

I've created a heap of saga grid files for some hydro survey work. I'm looking at a way to read these into a mapguide raster/grid layer, I'm able to load up the grids using a vrt file, I can't figure ...