The process of converting features on a map or image (either hardcopy or digital) to vector-based data in digital format.

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2
votes
2answers
154 views

Conditional Value Map widget in QGIS

I am looking for a way to implement conditional value mapping in QGIS. This means that the values available in attribute number 2 depend on the value provided in attribute 1. Example: If the user ...
1
vote
2answers
102 views

QGIS: digitized object disappear when filling in attributes

When digitizing, for example a point, the attribute window opens for you to fill in the pre-defined columns/information. But no point is shown in the map while you do this in QGIS 2.6. It was shown in ...
1
vote
0answers
227 views

How to OCR topographic maps

I have old topographic maps that i have scanned and converted into pdf in Actobat XI 11. I need this pdf to be text-searchable (not mere image). To do this i tried text recognition in acrobat but it ...
0
votes
1answer
58 views

Same Image and Shapefile are not overlapping in ArcGIS for Desktop?

An image is Digitized in ArcView 3.3 with JPEG extension; But not with Image analysis extension. When I open that image and shapefile in ArcGIS 10.1 for Desktop then they are not overlaping each ...
6
votes
2answers
1k views

How to digitize building footprints with orthogonal edges?

Using QGIS, I am trying to digitize an old raster map, and because I ultimately want to load these 2d layers into sketch-up to turn into 3D models, I need everything to be square. Here's a sample of ...
2
votes
1answer
479 views

How to implement Add feature action from PyQGIS

I'm trying to implement / reuse Add Feature functionality in my python plugin. there a class/function that handles geometry creation on canvas based on layer geometry definition? I'm checking API but ...
2
votes
2answers
306 views

How to automatically convert dots on paper maps to vector points?

I have several paper maps with dots that I need to convert to vector points. I was hoping to get some suggestions on how to accomplish this without recreating each and every point by hand. I know ...
3
votes
2answers
527 views

How to digitize rectangles with snapping in QGIS?

Trying to digitize a floor plan for a building (just need polygons for each room) in QGIS (shapefile layer). I started just trying to draw the features, but want to align polygons so that there is no ...
0
votes
1answer
197 views

How to change the QGIS edit cursor and node icons?

Two things I really dislike at QGIS, are the "fat" node icons (when editing lines) and the cursor which cover the object below and make it impossible to accurately move a node. Is it possible to ...
2
votes
2answers
213 views

ArcGIS lines to polygons without holes

I have a dataset with contours. Depression contours are separate of the normal contours and need to be digitized counter-clockwise. Still, there are usually some faulty ones with wrong direction and ...
4
votes
2answers
813 views

Adding Eastings and Northings as attributes automatically to a point layer in QGIS

I have a point layer that I am adding to and am working in British National Grid. Two of the columns are Easting and Northing. When I add a new point I want these two columns to be filled out ...
1
vote
0answers
37 views

Creating sub-polygons based on underlying basemap?

I'm looking at ranging patterns where animals go in and out of nature reserves into residential areas. In addition to home range polygons, I've generated polygons made from applying 25m and 50m ...
1
vote
6answers
301 views

In what real-world examples do users still digitize features from a map?

Is digitizing of map features completely dead? For example, when and why do you still digitize features from a map? It can be heads digitizing up from a scanned paper map (or image, or whatever) or ...
4
votes
0answers
266 views

How to digitize in stream mode in QGIS, using a tablet?

How to digitize in stream mode in Qgis, using a wacom cintiq tablet? freehand it's no use. i need something like MNDR stream digitizing extension for arcview 3.x, which allows continuous tracing, ...
2
votes
1answer
201 views

Digitizing takes a long time [closed]

While in the process of digitizing for instance a large body of water or piece of land it takes a long time to process. Is this normal? If not what can I do to speed up the process.
2
votes
1answer
537 views

Why are my polygons automatically simplified/generalised when merging them in ArcMap 10.2?

I am creating a small land use map, as an exercise for visual image interpretation. I created a shapefile and started digitising polyogons with the polygon tool. The problem is that some of my ...
4
votes
1answer
173 views

What is the fastest way to digitize features on a map?

I'm currently using QGIS basically to trace a bunch of polygons to show individual ponds from google maps. Some of the geometries can be pretty oddly shaped and using the nodal digitizing tool gets ...
4
votes
1answer
497 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
95 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
70 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 ...
2
votes
1answer
874 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
945 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.
5
votes
1answer
766 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
356 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 ...
3
votes
2answers
391 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
275 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 (http://george.wildlifeintel....
1
vote
0answers
86 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
46 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
295 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
65 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
114 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 ...
4
votes
1answer
3k views

Is there a QGIS bezier curve tool?

I'm a recent convert to QGIS but have been confused about the lack of support for drawing curved shapefiles, especially when Arc has almost too many. A lot of the work that our consultancy do is based ...
2
votes
1answer
87 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
1k 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 ...
1
vote
1answer
702 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
1k 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
233 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 ...
3
votes
0answers
1k 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
166 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 ...
1
vote
2answers
54 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: ...
3
votes
3answers
822 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 ...
2
votes
1answer
307 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 ...
5
votes
2answers
8k views

Showing polyline direction in ArcGIS for Desktop (ArcMap)?

How can I 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 but my trial ...
1
vote
0answers
78 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
81 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
48 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
2k 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
228 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
274 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
32 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 ...