1
vote
1answer
438 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
2answers
140 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
75 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
61 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 ...
3
votes
1answer
104 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 ...
2
votes
0answers
184 views

how to make decent sense from scattered river depth measurements

I sampled river depth at scattered positions and I want to be able to make a map and GIS layers out of it. My problems are: As the river meanders the interpolation I do in scientific packages i,e. ...
1
vote
1answer
176 views

Restricting Tin interpolation in QGIS

I am trying to do a bathymetric map for a lake using QGIS. However, I see no option to impose a mask so interpolation does not extending beyond the boundaries of my lake. I have traced around the ...
3
votes
1answer
180 views

Masking/removing polygons from shapefile

I have a shapefile containing the road traffic noise of a city. The shapefile has 5 columns, where 'noise_in' (noise interval) ranging from 1-5 is included. I want to remove/mask the road noise from ...
1
vote
1answer
377 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 ...
1
vote
2answers
201 views

How to mask out features outside of the Coverage Layer for Atlas plugin? [duplicate]

Using the Atlas plugin for qGIS how do I set the coverage so that it will only highlight the feature(s) I want but still show the surrounding features as grayed out areas? This would have been easy ...
1
vote
1answer
164 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 ...
3
votes
4answers
2k views

How do I create a mask where the masked area can be changed by selection?

I'm working on making a mask in QGIS to have one area(county A) outlined while the other areas(counties) are under a semipermeable layer. I already know how to do this for one selected area. But my ...