1
vote
1answer
97 views

Clip raster layer with *raster* mask layer in QGIS

Given two input layers 1. The clip layer - an arbitrary layer (though in my case it's a float 1 band geotiff) 2. The mask layer - a paletted raster in which every pixel is either NO DATA or a single ...
1
vote
1answer
71 views

How to change raster cell values within a polygon using QGIS GUI?

I would like to know how to change the values of raster cells which are within a polygon, leaving all cell values outside the polygon unchanged. I would like to subtract 1.5m from each raster cell ...
4
votes
1answer
63 views

Cutting Raster using two Polygons as Masks

I am trying to cut this raster in order to drop the outside of the walls white area and the area with the dots. I made one step using as mask the green polygon but i couldn't remove the inside of the ...
2
votes
1answer
38 views

Raster topo map “collars” overlap

I am using QGIS 2.0. I have downloaded USGS 1:100,000 topographic maps which show adjacent areas. The topographic maps were digitized with the borders (I've seen them called "collars", I think) as ...
1
vote
1answer
119 views

combine raster with another raster mask file - gdal

I have 2 rasters in GeoTiff format. One has all of the land and water and the other is a mask file that shows either 0 for water or 1 for land. I basically want my output to just have the land values ...
1
vote
1answer
92 views

How to extracting raster data to multiple polygons?

I have a reclassified raster dataset (10 classes) and I want to find out the area of each class contained within multiple (hundreds-to-thousands) polygons. I have all the polygons in the same ...
3
votes
1answer
79 views

Create a band mask based on pixel locations, not in pixel values

I have this image loaded in QGIS, with two possible values for the pixels: 1 = orange, 2 = blue For simplification, assume it represents a province of a country. I want to extract just the part of ...
0
votes
0answers
24 views

Create a mask for a 3 Band Raster Image with surrounding white areas

How do I create a mask in order to clip a 3 band raster image so that the surrounding white area does not display. My thinking is to use Raster Calculator to create the mask or cut all three bands on ...
1
vote
1answer
283 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 ...
5
votes
2answers
221 views

How to modify raster pixel inside a polygon?

I would like to set to novalue all the pixels of my raster inside a polygon. I'm trying the gdalwarp command line with -cutline option. But this command extract the values of my raster inside the ...
6
votes
3answers
1k views

How do I use polygons to apply a unique value to all raster cells within those polygons?

In ArcGIS 9.3, I have a raster file that I would like to "mask" with polygons, giving a single value to all the raster cells that overlap the polygons. How can I do this? Here's a screen shot, where ...
1
vote
1answer
148 views

Clipping Rasters with a mask layer error

I've got a NDVI layer that I'm trying to clip with a vector file but when I try and use GDAL Tools clipper I get an error. That shows up like this: What am I doing wrong? This is before I even pick ...
7
votes
1answer
350 views

Reduce extent of raster processing

I need to reduce the processing extent of my raster by some sort of automatic procedure in python. Currently the borders of the dataset I've been using has anomalies (due to the classification of the ...
6
votes
1answer
892 views

Creating a mask with transparent pixels in python

I have a geotiff image with pixel intensities ranging between certain values. Lets say bewteen -2 and 2 (the image is normalized). I have a certain threshold which interests me, lets sat 1. I would ...