Tagged Questions
0
votes
1answer
42 views
Maintain 8-bit pixel depth in Raster Calculator
Would anyone know how to maintain 8-bit pixels when computing raster calculations in ArcMap?
2
votes
1answer
40 views
Nearest Neighbor Focal Statistics and Map Algebra
I would like to use a nearest-neighbor type analysis to iterate over a raster. The nearest neighbor analysis will give a cell value of 1 IF AND ONLY IF the cell being analyzed has a cell value larger ...
1
vote
1answer
67 views
Copy and Paste symbology in Raster?
Hi all,
I am trying to figure it out how can I take a preserved color from a raster I already set up before and then apply the colormap to a new raster file?
Here are the details of what occurred:
...
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 ...
7
votes
1answer
141 views
Calculating distance from points to different class in raster
I am looking for some advice on how to calculate the distance from a point to a different class of a raster. Specifically, I have observations (points) of animal use overlaid on land cover data. For ...
0
votes
0answers
27 views
Isolate And Save Raster Features From Existing Multivalue Raster Map
I have Cyprus Corine map with 44 different types of land use.
I want to run a raster calculator query or any other way to isolate the areas with codes 10 to 22 and 26 to 34, all other values 1 to 44 ...
1
vote
1answer
632 views
reclass, raster calculator
I'm trying to apply seperate equations for different land types. I have created a raster containing only the land type I'm interested in. I then reclassed the values to '0'. My plan was to use the ...
1
vote
2answers
296 views
QGIS Raster Calculater Syntax
I am trying to use the raster calculator in QGIS to combine a number of rasters. I want to calculate a mean, this is easy:
(raster_1@1 + raster_2@1 + raster_3@1) / 3
I then want to create a max. ...
3
votes
1answer
127 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
151 views
Question about sizes of input rasters for raster calculation
To calculate any formula (conditional statements/relational operation etc) in the raster calculator in ArcGIS using two different sources of raster images, I'd like to know input rasters must be the ...
5
votes
1answer
107 views
Calc bottomline of valleys
Which way do I calculate bottomlines of valleys or even more preceise:
which way do I "find" valleys (for example suggested tectonic faults).
Sample below shows a height profile (profile from line) ...
1
vote
1answer
116 views
Trying to run raster calcuatlor to build an expression for ls factor
I am trying to run a raster calcuatlor but it failed. I believe there is a word that ArcGIS 10 does not understand resolution. Maybe there is a word that needs to be interchangable for this ?
I took ...
0
votes
0answers
61 views
how to calculate the spatial mean in a region in one raster which correspond to another raster? [closed]
I have a raster map(sed) that I want to calculate the spatial mean of specific region and display that as a layer.I do not just one value,I want to display the area too(even if the value is the same ...
8
votes
1answer
328 views
How to make a new raster using con() script in Python?
I'm new to Python and have been trying to code a raster calculator style script. Basically, I want to convert a raster that has values 0 to -10,000 into a raster that is populated by 1s between ...
2
votes
1answer
50 views
How could I assign point values to a raster stream segment?
I need to assign a point value in raster format to a raster stream segment, which contains the point. See bellow:
The expected result is a segment, whose value is the point value. How could I?
2
votes
2answers
476 views
query raster in ArcGIS 10
I am using ArcGIS 10 (includes spatial and geostatistical analyst). I have a raster (GRID) with a value range of -167 to 18. I would like to query the raster and create a new one with only the values ...
5
votes
1answer
409 views
Raster processing with Python or Arc raster calculator
I have 4-band NAIP imagery that require the following processing steps:
Convert to 8 bit unsigned B/W
Reverse (note not inverse) the image, so that dark values appear
light and light values appear ...
3
votes
1answer
166 views
how can I obtain the areas where my rasters overlap, using Qgis?
I have a bunch of raster files showing the distribution of different species of mammals, and I would like to obtain the areas where they overlap, the areas in whitch more than one species can be found
...
3
votes
1answer
2k views
How to crop raster layer?
Can anyone tell me how to crop a raster layer in QGIS? I want to make contours from a section of a layer, and including the whole layer will create far more data than I need and slow down the ...
2
votes
1answer
357 views
How to calculate a new raster based on nodata values from original raster, in QGIS?
I'm using the raster calculator from core in QGIS and I need to generate a new tif raster file (mask) from the nodata values of another tif raster file. I tried isnull(), but no luck. Any one can ...
2
votes
2answers
154 views
Is it possible to attain a classified raster with several classes in just one QGIS raster calculator operation?
I'm using qgis' raster calculator and wanted to make a new raster (oraster) from the values of an input raster (iraster). something like:
if iraster>2 then oraster=1; if iraster >4 then oraster=2; ...
5
votes
2answers
928 views
Using individual bands from a multi-band image in ArcGIS 10 raster calculator
I'm trying to use individual bands from a multi-band TM image (IMG file) within the raster calculator in ArcGIS 10 (SP2/3). I can add individual bands to my MXD, but raster calculator will only use ...
