The process of converting the geographic features on an analog map into digital format using a digitizing tablet, or digitizer, which is connected to a computer.

learn more… | top users | synonyms (1)

4
votes
1answer
94 views

Digitizing contour lines from paper maps using QGIS?

Is it possible to give digitized altitude lines (from paper map) heights using QGIS?
3
votes
1answer
37 views

How to insert some holes in a polygon?

I have a problem with QGIS digitizing advanced tool plugin. I have a landcover-like shapefile. I have to perform some corrections on it, and I have to cut or split some polygons. I want to insert some ...
2
votes
0answers
22 views

How to digitize a custom road?

So I've built my network and now I am creating custom bus routes. However, one of my bus routes makes a stop on a private road that I had not realized was included in my network. How should I go about ...
1
vote
1answer
35 views

“Node tool: could not snap to a segment on the current layer” message

I have a strange issue. Editing a layer with node tool I get always the following message: "Node tool: could not snap to a segment on the current layer." This error happens to me even with a fresh ...
1
vote
2answers
96 views

convert a *.jpg scanned from line paper map to vector data in arcgis

I want to digitize automatically old paper map that scanned to jpg . I know that it's possible to digitize it with arc-map but I can not remember how to do it.
4
votes
1answer
88 views

How to split a line into a specific number of parts?

I've seen a lot of questions involving splitting a line with the help of a point layer. I want to split a line in fractions of its length. For example, I have a line 400 meters long, I want to split ...
3
votes
0answers
61 views

How to snap and move circles by the center?

I have a point layer, and a polygon layer with buffers of a given radius around each point. I need to move points, and check that each buffer is not above forbidden land/plots. In autocad, you can ...
1
vote
0answers
50 views

QGIS Freehand editing plug-in: blocked attribute table

I can't save object after drawing by Freehand editing plug-in. I suppose it will be connected with creating some (special) column in the table. Could anyone suggest a solution?
3
votes
1answer
41 views

How to digitize RGB TIFF automatically

Is it possible to digitize RGB TIFF by color - I need to select all the vegetation cover types from the image below, which is a part of an aerial photography of an island ...
1
vote
0answers
37 views

How to set a defined distance between nodes to digitize in qgis?

Using QGIS (by now I have the 2.4 version) I would like to set some parameter (I don't know if such exists) that would impose a definite or maximal distance between nodes when digitizing a polyline or ...
1
vote
0answers
39 views

automated method of Geo-referencing air photos?

I am trying to figure out a way to automate a process to geo-reference ~800 air photos, followed by digitalizing several thousand polygons from these air photos. At a minimum, we would like to create ...
2
votes
1answer
141 views

How to find the projection of an image?

Instead of georeferencing the image and deforming it, I'm trying to find the projection used by the author of the image. I've got tens of these distribution maps to digitize. The idea is to avoid ...
0
votes
0answers
34 views

QGIS Fill Ring tool problem

Using the new (in 2.2) 'Fill Ring' tool and it doesn't seem to work correctly in all cases. It seems that if I try and digitise the new ring close to the polygon boundary, TWO (or more) geometries ...
0
votes
0answers
68 views

Digitizing with OpenLayers Plugin seems incorrect

I am attempting to digitize some buildings based on floor plans using QGIS. To do this, I have taken the blueprints, georeferenced them against openlayers bing aerial plugin. I then digitized the ...
2
votes
1answer
39 views

unable to draw polygon without attribute window popping up?

I'm fairly new to QGIS and an trying to draw a polygon via "Adding Feature". When I make the first left click to start, the attribute window pops up instead of letting me continue on with additional ...
1
vote
1answer
164 views

How to indicate flow of a watershed feature?

While tracing and digitizing rivers, streams, rivulets, etc., is it possible to indicate the direction/flow in the shapefile on QGIS? I'd like to avoid using map labels. Ideally, when done tracing, I ...
0
votes
0answers
44 views

Split/Erase/Differentiate polygon by polygon within a same layer

Is it possible to split a polygon with a polygon within the same layer in QGIS ? As in the image, i want the Polygon 2 to be split & the pointed area has to be retained as a separate polygon. ...
1
vote
1answer
139 views

Can I resume (continue) digitizing a polygon feature from any vertex?

When I digitize in ArcMap with a Wacom tablet and a pen I often accidentally double click and finish my sketch. More often then not the accidentally finished sketch crosses itself. I would like to ...
1
vote
1answer
335 views

How to go with…somewhat complex geological maps in QGIS?

Just a follow-up to this question QGIS: Line to polygon conversion. Not sure do i have to continue there itself... We are currently digitizing a geological map...which has 36 features in total. Some ...
1
vote
1answer
91 views

QGIS: Line to polygon conversion

Currently we are working in a geological project..in which all the Contacts, Linear & some other geological features have to be captured. The thing is most of the features have to be Captured as ...
1
vote
0answers
347 views

How can I create/draw “freehand” polygon features in QGIS 2.2?

I installed the Freehand Editing plugin but it doesn't seem to work with the latest version of QGIS; the icon appears on the Ditizing Toolbar but the icon is disabled. Is there any way to use a ...
1
vote
0answers
54 views

How can I optimize ArcMap Editor's streaming mode for use with a tablet such as the Wacom Intuos?

I have the Wacom Intuos 4 Large tablet which I use occasionally outside of ArcGIS. I now need to digitize a large volume of polygons from aerial imagery and am finding the tablet's ArcGIS ...
0
votes
0answers
35 views

Converting from Vector to Raster [duplicate]

I am still a beginner using QGIS 2.0.1-Dufour. The shapefiles are from British Ordnance Survey via Stanfords. I am doing a geographical/historical study on a village in Somerset, UK. I want to show ...
1
vote
2answers
49 views

Which value should I assign my digitalized features?

I have a scanned an old document that contains geochemical interpolated values (no way to work with the digital file). This is the original image: And this is the digitalization I made from it: ...
2
votes
2answers
319 views

“add feature” tool QGIS 2.0 - polygon fill blocks view of what I want to digitize

How can I change the settings on the vector "add feature" tool so the tool fill doesn't block my view of what I want to digitize? This problem popped up after I upgraded to QGIS 2.0 QGIS 2.0 ...
1
vote
1answer
118 views

Heads up digitizing - Polygons overlay differently with two different Satellite images

I have been digitizing building footprints from satellite image using ArcGIS 10.1 . Field data collections is done with the use of four corner point GPS way point. Due to multipath errors, we are ...
3
votes
2answers
2k views

How to show polyline direction in ArcGIS for Desktop (ArcMap)?

can someone tell me how I can show the direction of a polyline as it was digitised? I need this to check if my network analysis is obeying one way streets...I know of a tool in Xtools that can do this ...
1
vote
0answers
58 views

When digitizing, polygons are inverted

I need to use QGIS to digitize my images. My images are scanning electron microscope (SEM) images of rocks. I am interested in analyzing the pore space in the images. Here is the steps I follow: I ...
0
votes
1answer
52 views

Line style width property not being applied in QGIS 2.0.1

I change the line width of my style and click apply, but the property does not seem to be applying to my line data.
0
votes
0answers
46 views

Polygon shading is darker in certain areas

When drawing in qgis i am encountering an error when drawing large polygons snapped to multiple points. Polygons that have this shading in certain areas are not displaying correctly in other ...
3
votes
2answers
851 views

Figuring out map scale when you know the spatial resolution of a Satellite Image?

I'm interested in figuring out how map scale and satellite pixel size (spatial resolution) are related. For example the TM or ETM+ has roughly 30m ground resolution, then, what could be the finest ...
0
votes
2answers
156 views

Which one is best open source GIS software where we can use Google/bing/yahoo maps as a basemap? [closed]

Which one is best open source GIS software where we can use Google/bing/yahoo maps as a basemap? i want to update my shp files using any of these basemap.
1
vote
3answers
95 views

How can I create a simple basemap in QGIS that will allow me to trace a polygon with an accurate projection?

I need to find an aerial photograph, create a new vector layer, trace several fields in this aerial photograph, and find random coordinates within these polygons. I first tried this with the Google ...
1
vote
1answer
28 views

Searching 'select by color' for raster or map data

I'm planing to create an online map component with which the user can create/draw polygons based on underlying raster data. Is there some library / tool / procedure existing which enables the ...
6
votes
3answers
2k views

How to digitize a raster automatically

I have a raster (.sid extension) file. I want to digitize roads automatically in ArcMap, QGIS..etc. Digitizing by hand would be too time consuming. How can i do this ? Thanks
0
votes
1answer
215 views

Create new regions in layer by filling in between polylines on existing layer

I'm not sure if this is possible but would save me hours of work. I have a layer which consists of polylines. Most of those polylines bound areas; houses, roads, etc. Currently I am required to ...
0
votes
1answer
108 views

Draw lines for existing list of data

I have a csv file containing information for loads of lines (dates, road names, condition information, etc etc) but which have no geographical information (other than the association of road name) Is ...
1
vote
1answer
153 views

using the “freehand” construction tool

I am drawing hydro features with the freehand tool. Does anyone know how to delete vertices (i.e. back up) in ArcMap 10 while drawing with freehand in the construction tools? I was just curious if ...
4
votes
2answers
286 views

ArcGIS Heads up digitizing - Rooms and doors

I am digitizing the floorplans of various schools in our county. This is for the Fire Department so they want to be able to see where doors are within the building. The doors do not necessarily have ...
5
votes
2answers
146 views

Any Piri Reis shapefiles?

Incredible claims have been made about a map named after its creator (Piri Reis). I was looking into digitizing the map and overlaying it with a modern map of the world, specifically the east coast ...
-2
votes
1answer
670 views

How to digitize a map in QGIS?

I am relatively new to QGIS and using it on windows vista. Problem: I have to digitalise an aerial map and then extract the coordinates. I have absolutely no idea how to start Thanking you in ...
1
vote
1answer
113 views

Digitized vectors don't match while zooming [duplicate]

I'm trying to digitize in QGIS with Google Maps as the background. Digitizing with constant zoom works fine. But if the zoom is changed, the digitized vectors don't match the Google Maps background ...
1
vote
2answers
129 views

How to make digitization more detailed afterwards with QGIS?

I digitized already two areas, bordering each other on one side. Than I realized, more detail was needed! What do you suggest as a fast way to do so? Adding each time new dots/verteces takes so ...
3
votes
2answers
137 views

I am unable to draw a shape layer

When I add a new shape layer or want to edit an existing one, nothing is happening. I even don't see the dots where I'm clicking. Maybe the problem is I deleted some layers (by opening the .qgs as a ...
1
vote
0answers
65 views

When digitizing, objects are not saved well

I've some problems with digitizing. If I draw a line or a polygon, the line or polygon is saved in the attribute list, but not visible and its location is not saved either (when I zoom to the object ...
0
votes
2answers
887 views

Digitizing from OpenLayers Plugin in QGIS, or create raster?

Is there an easy method for digitizing from a layer added from the OpenLayers pluggin. As i cannot snap to it or use it as raster so the entire map does not load? two separate issues there.
3
votes
1answer
201 views

digitizing (tolerence) error in line data

I have designed a large number of boundaries. For accuracy, I took lines in patches from different data sets and merged them into one. Now I want to turn them into polygons from lines. I every second ...
4
votes
4answers
1k views

How to Digitize Free Satellite Imagery in QGIS - Alignment issues with Openlayers Plugin

I am trying to digitize OpenLayers data (such as Google satellite imagery) with no success. Whenever I try to move or zoom the canvas the vector layer I digitized loses the position relative to the ...
7
votes
1answer
429 views

How to rectify polygon shapes in QGIS?

I have some polygon-shapes in qgis-1.7.0 and want to ensure that every polygon is a rectangle. See image below. Is there any way I can do this in QGIS (or any other f/oss)? Or how can I improve my ...
3
votes
0answers
98 views

How to digitize 90 degree angles? [duplicate]

Possible Duplicate: How to create polygons with straight lines and right angles in QGIS? In QGIS 1.8 is there a way to digitize buildings etc. with perfect 90-degree angles, Or, edit a ...