Tagged Questions

1
vote
0answers
52 views

Reclassifying a raster based on values in another raster

I am attempting to create a new raster based on the values of two rasters I have already created. I am using ArcGIS 10.1 Raster1 is an area with my true values. Raster2 was created by reclassifying ...
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
1answer
106 views

How to reclassify grey scale tiff in qgis

I downloaded a raster image of the sea floor age. The values in band 1 ranges from -32768 to 32767. I need to reclassify it to no. of million of years to make sense of the data. How can I do so? I try ...
0
votes
1answer
108 views

How do you use 'reclass' in GRASS?

It could be user error, but for some reason, the reclass tool is just hanging and hanging... QGIS 1.8 Compiled against GDAL/OGR 1.9.2 Ubuntu 12.04.1 Running the tool from the Sextante toolbox Input ...
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 ...
8
votes
2answers
366 views

How to reclassify a very large land cover dataset?

Consider the NLCD2001 Land Cover dataset for Alaska (download link). I need to reclassify this dataset so that only pixels of value 41, 42, and 43 are preserved; all other pixel values should become ...
6
votes
2answers
567 views

How to change null values raster values to 0 in QGIS?

I need help... I'm having problems with QGIS. I have some rasters that appear to have null values, even though I reclassified them to obtain a boolean raster :( How can I change the NULL values to 0?
1
vote
0answers
116 views

Reclassify ESRI raster using variables from a SQL Server table (connecting with pyodbc)

I am trying to reclass a raster file (representing vegetation and land cover types) using values stored in a SQL Server Express table. I have a set of ~400 species records in the table, with each row ...
2
votes
1answer
280 views

Creating a constant elevation raster with multiple attributes

Is it possible to create a raster with a constant value with multiple attributes? Such as: rowid value count Name 1 630 36000 Forest 2 630 75000 Anthro 3 630 2600 ...
3
votes
1answer
70 views

What proportion of the 240m area sensed by MODIS must be forest before it is defined as forest?

MOD12 is a MODIS product at 240m resolution. Landsat produces 30m resolution products, which I resampled to 240m resulting in a raster of proportion forest cover in each 240m pixel (based on the mean ...
4
votes
1answer
102 views

Reclass all values < 0 to -9999 in PostGIS

I have a tiled raster in a PostGIS table and I would like to change the value of all pixels which have values less than 0 to -9999. How should I do this? I suspect it involves ST_SetValue and ...
3
votes
2answers
904 views

Reclassify raster values of 9999 to NoData, leaving all other values alone, in ArcGIS

I've got a really stupidly simple question, but I can't seem to work out how to do it. I have a raster in ArcGIS which has a number of cells with the values 9999, showing that the data could not be ...
8
votes
2answers
2k views

How to perform Raster Reclassification in QGIS?

Is there a way to do reclassify a raster image to Qgis? In Arcgis you can do that in Spatial analyst Tools-->Reclass-->Reclassify Any ideas?