Rasters are regular grids of values, usually stored in an image-like format.
1
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1answer
55 views
How to set min and max value for stretchType: esriRasterStretch_PercentMinimumMaximum
How can I set the min and max values for the stretch type "Percent Clip" in arcobjects?
It's possible to set the Stretch type:
rasterStretch.StretchType = ...
2
votes
1answer
99 views
How to reclassify a float raster?
I have three rasters which represent distance (in metres) from certain things (bus stops, parks, libraries). I would like to reclassify these rasters so that they get integer values based on the ...
2
votes
0answers
62 views
Raster area (QGIS) problem explained
I would like to know the area that each value in a raster has... The raster I have has values from 2-15 and I would like to know the area that each value is occupaying within my polygon... Thanks!
I ...
0
votes
0answers
36 views
Why are areas of raster and polygon after digitization not matching? [duplicate]
I have followed the answer given in this question:How to calculate the area of rasters in QGIS?
I vectorized and calculated the area using geometry columns but I a faced a strange problem.
When I ...
0
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0answers
14 views
Raster pixel calculator [duplicate]
I have used model builder to calculate a site suitability raster using the weighted overlay tool. I now have a site suitability raster and I have to pick one of four polygons that overlay the raster ...
0
votes
2answers
50 views
Export Raster with classification colors in ArcMap
I have a single band raster, but i like to export it with the same colors as in Arcmap.
Any help please.
0
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0answers
59 views
GMT raster (*.tiff + *.pgw) in epsg4326 shifts few kms (4326-900913-3857 problem?)
This seems to be an old problem with an already known solution (ie. "...stop using 900913 and start using 3857..."), but not sure whether this problem is about software versions, the raster itself or ...
0
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2answers
101 views
Grass 7 / ArcGIS 9.3 - tiff to raster
Again a Grass 7 question. I have the output of a modelling run as matlab file, which I can export as tiff and load as geotiff. OK - now can I extract the data/convert this tiff into a raster proper?
...
0
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0answers
12 views
How to create symbology? [duplicate]
Please suggest how to create symbology in QGIS? As I am Infrastructure layer with the help of QGIS and I want to represent different roads with different colors and widths but right now I am unable to ...
1
vote
1answer
44 views
Grass7 - r.regression.multi and new raster
I am on the learning curve with Grass7. I managed to make r.regression.multi work, but there is one thing that would be of high interest for me: it is possible to create a new raster showing the ...
8
votes
1answer
114 views
What is some theory on the number of GCP when georeferencing?
Just wondering, is it always better to have more than 3 GCPs? Should the GCPs be spread out evenly? Where can I find some general resources on the theory of this? Other than trial an error, which ...
3
votes
1answer
472 views
What is the difference between Vector and Raster data models? [duplicate]
From: http://support.esri.com/en/knowledgebase/GISDictionary/term/vector%20data%20model
vector data model: [data models] A representation of the world using points, lines, and polygons. Vector ...
0
votes
1answer
110 views
Problem to clip a raster with a shapefile
I need to clip a rasterlayer with a vector layer. When I try this, the following error appears:
**ERROR 1: Attempt to create 0x0 dataset is illegal,sizes must be larger than zero.**
What am I ...
1
vote
1answer
41 views
raster tile - find the correct tile for a given coordinate
I have a large raster map which I loaded into postgis with 1000x1000 meter tiles... the corresponding table has about 200 rows, each row representing a tile. I want to get the raster value for a ...
0
votes
0answers
25 views
GDAL Error 1: Can't find RasterDMS field in Eimg_Layer with block list
I've got a dataset consisting of an .aux file and an .rrd file with the same names.
When I open this data using the GDAL C++ library (applying GDALOpen to the .aux file), the dataset seems ...
2
votes
1answer
61 views
Raster calculator - reduce all value above certain value
I have a probably quite simple question: I have a raster with elevations above 2000m that I want to "cut" to 1800m. I cannot quite figure out the correct string and most simple way to do this in the ...
5
votes
3answers
104 views
What is a simple binary raster storage format which ArcGIS can read?
I have a C++ program that manipulates raster digital elevation models.
I have been using ArcGrid ASCII format for results. It is simple to code and gets the job done, but it necessitates a decimal ...
13
votes
3answers
195 views
Which CRS would you use to georeference historical world maps?
Which CRS would you recommend to georeference historical world maps like the ones in the London Geographical Institute - The Peoples Atlas - 1920, e.g.
The map displays a lat/lon grid which I would ...
3
votes
1answer
49 views
Differences in raster extents in gdalinfo, SAGA & Quantum after resampling
I recently resampled a raster file using SAGA's Resampling module. The aim was to widen the extent of the new raster to two decimal places, where the original raster has three decimal places. The ...
1
vote
2answers
75 views
Reducing the resolution of a huge raster
I'm not much of a GIS user, but I've got a big ascii file that I'm trying to convert into a
lat long data
x1 y1 d1
x1 y2 d2
x1 y3 d3
x2 y1 d4
...
etc
format, so that I ...
0
votes
1answer
56 views
Algorithm to merge adjacent raster datasets
I am trying to figure out how to merge adjacent raster datasets.
Is there any clear algorithms (may be a pseudo code)?
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0answers
38 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
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0answers
23 views
Attempts in C++ to read only a window of a raster fails using RasterIO. Can Help?
Under C++: I can read a raster image just fine if I read the whole thing one line at a time using RasterIO. If I follow the documentation fr reading a window, however, I get error messages that make ...
2
votes
0answers
56 views
How to create raster attribute table to a raster data using gdal python?
I classified a remote sensing data and saved it as a raster using Gdal python. I want to create a raster attribute table for this classified result.. my classified raster has five classes with ...
0
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0answers
38 views
How to change integer labels into strings for a raster layer and publish it as a map service to retrieve its legend?
In ArcGIS Desktop 10.1, I've got a raster layer that uses an internal colormap to draw its symbology in the TOC. The result is an integer value for each color symbol classification. I can edit ...
2
votes
0answers
25 views
Automatically discard nodata area of raster [duplicate]
Given a raster with an overly large nodata surround, how can I automatically discard the surround? Said another way: how does one shrink the raster extent to only occupy the area containing values?
I ...
2
votes
1answer
27 views
Can TimeManager animate a large number of rasters in QGIS?
I understand that as of a year ago, the TimeManager plugin was not intended to handle more than a handfull of rasters. This post is in blind hope that this has changed!
I'm trying to create a map ...
0
votes
0answers
38 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 ...
1
vote
1answer
82 views
How to invert polygons (or other options for exterior styling)?
I have a shapefile containing many polygons that I want to use to mask a raster. I have tried gdalwarp -cutline <shapefile> -crop_to_cutline -srcnodata -9999 -dstnodata -9999 ...
3
votes
2answers
111 views
Overlay Vector Layer on Raster Layer
How can I overlay a Vector Layer on a Raster Layer and assign NoData Values on the Raster where the Vector Layer does not cover the Raster Layer?
(preferable with ArcGIS)
1
vote
1answer
79 views
raster statistics - regressions between raster data
I have the following problem:
I have two set of rasters, with data that should correlate...one are measured data, one are modelled data. The correlation is weak, however, when looked at with a normal ...
0
votes
4answers
54 views
How to clip rasterdata for later processing?
My need to dwell with geographical tools is only temporary, thus I am not well versed and my question is difficult to pinpoint exactly. But here it goes:
-I have about 5-10 sites, for which I need ...
1
vote
1answer
82 views
Where is the File Geodatabase Raster Dataset file stored?
I have a esri file geodatabase with a raster dataset. How can I find out which physical file the dataset is referring to?
(I am retrieving the file geodatabase through the internet. It all seems to ...
1
vote
4answers
50 views
Batch visualization of raster (grid) files
I have about 100 raster (grid) files (in the "ascii grid" format) of drought index. All cover the same area of interest but at different times of year. I need to create images from the grids with ...
2
votes
1answer
175 views
GDAL_translate: converting ESRI GRID to Geotiff in batch
The Challenge:
To batch convert 1000 rasters in ESRI Grid binary to Geotiff using either using a batch file or Python 2.7 without ArcGIS/Arcpy module.
The Tools:
Win7Pro, GDAL 1.9.2 (via OSGeo4W), ...
1
vote
0answers
58 views
Why Stacking rasters return all values as NAs?
I have several rasters that I want to do some calculations ,basically calculating the moving average.
dir2 <- list.files("D:\\2010+2011", "*.bin", full.names = TRUE)
...
2
votes
1answer
59 views
Zonal Statistics-Weighting
I have a raster file on precipitation and I want to create zonal statistics as a table using a shape file wiht boundaries of countries across the world. However it appears that I need to take into ...
0
votes
0answers
41 views
R-raster versus ArcMap Bioclim clipped values differ?
I have a set of lat/long ccordinates for which I wanted to pull corresponding BioClim (1-19) values. I first used ArcMap, without interpolating, and came up with a set of data. I then used R's ...
4
votes
4answers
113 views
How to display a “Save As” dialog for raster files?
I'm writing a QGIS plugin in python. I need to show a "Save as" dialog window in order to allow the user to select the path of the output raster file. Do I need to create a QFileDialog and manually ...
2
votes
0answers
61 views
Point file to raster
I have a point file of trees in my study area, which includes the attributes of each tree. Each tree also has a crown radius associated with it. I need to summarize the attributes of these points ...
3
votes
3answers
101 views
query raster cell values by point
I have a binary raster (0s and 1s) that I need to query given a set of point coordinates. This is easy enough to do with gdal (gdallocationinfo), but where it get's complicated is that I also need to ...
1
vote
1answer
85 views
How to convert a shapefile polygon to raster in C#
Does anybody know a way to convert a polygon (vector) in a shapefile to raster data WITHOUT using ArcGIS Explorer Desktop? Is there a way to do this 'progmatically' in C# (WPF with ArcGIS runtime ...
1
vote
0answers
51 views
Join field from table to a raster layer
I'm trying to join a field in a table to a raster layer. I'm using the tool 'Join Field'. The table is in a excel sheet, but have been imported to a file geodatabase. The table has an ObjectID field ...
1
vote
1answer
29 views
BIOMOD Error message: argument of length 0
I’m using the package BIOMOD in R to modelling habitat in rodent species. The data formatting works but I'm getting this error message when I run Modelling:
## Conputing the models ##
...
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vote
0answers
55 views
Creating Raster with values based on function output
I have a function that calculates a price based on the input slope and distance. I want to write the price to a raster as the rastervalue. How do I do that? OpenSource and ArcMap solutions would work.
...
0
votes
0answers
63 views
question on terrain analysis in qgis particularly slope from .5 m dem
Trying to create representative slopes from .5 dem. It seems to do a wonderful job with the stream bottoms and also with the general trends. It shows it to be steep where steep and flat where flat. ...
1
vote
2answers
80 views
How can i make a polygon of cells of a raster
I have 100 rasters, each raster has the same cell size and extent and i want to make a polygon over of each cell. Can anyone help me doing this?
Thanks in advance.
0
votes
1answer
57 views
Can you use a large file directory of jpgs for without georeferencing
I have a large map data set of 256x256 jpg images. The file directory is organized by /map_type/zoom/x/y.jpg. I have 12 zoom levels and each zoom level directory has 2^(2*zoom level) images.
I have ...
0
votes
2answers
84 views
Make a “Shaded Area Polygon” from HILLSHADE raster in ArcInfo 9.3
How am I suppose to extract the values ( Value<=100 ) from this HILLSHADE raster, and then make the extracted values as a VECTOR POLYGON (shapefile)
---I'm using ArcGIS 9.3 (ArcInfo with all ...
4
votes
2answers
114 views
GDAL does not ignore NoData value
I am trying to calcualate the statistics of a TIFF. The script should ignore the NoData value, but doesn't. What causes this?
import gdal
from gdalconst import *
# register all of the drivers
...
