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Creating Geological Maps

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Creating Geological Maps

Gerhardus Geldenhuis
Hi
I am very new to Quantum GIS and the learning curve is a bit steep at present but I believe worthwhile. I will much rather do the work in Quantum GIS than work on a map in Illustrator.

Here is what I am trying to do and having difficulty with:
I spend a few weeks in the field creating a paper based geological map which is on a number of transparent sheets which I have scanned in and aligned properly. These maps where done on a 1:10000 scale and using UTM WGS 84 grid co-ordinates to make mapping a bit easier. I now want to digitize these images into a vector layer which I believe is the most appropriate. I also want to add Google earth and other source images. 
I also have a number of gpx files generated by my GPS which is another layer I want to add.

My first question is with regards to the png images that I am using. When I add these images as a raster layer they appear very dirty and when zooming in the detail is obscured as if someone has rubbed over it. At first I thought that the issue was jpeg compression which took away detail so I resaved the images as png files and double checked using various image viewers under Ubuntu that the image quality is up to scratch. So for some reason Quantum GIS is not displaying these images correctly how do I fix this?

Second question is how can I "align" this png file with with an actual co-ordinate system. I have marked 4 points on my paper maps and lines between these points that represent the UTM grid on which I worked and I would need to at least roughly align this image with the UTM grid.

Thirdly I am not sure how to draw on a new layer but still view my image as a template for the digitizing. 

I am more than happy to read any documentation and work through tutorials. What is lacking at the moment is the terminology to search for the correct things and experience. I am working through a number of tutorials but are still struggling a bit to connect A to B.

I will eventually add some ASTER imagery but it is my understanding that these are in tiff format and contains extra information like spatial referencing. I suspect that if I can master the above then adding ASTER imagery will be easy.

Lastly is there any geological map symbol databases available?

I would appreciate any pointers or brief/detailed outlines of the methodology I should be following to get best results.

Best Regards

--
Gerhardus Geldenhuis

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Re: Creating Geological Maps

Robert Szczepanek-3
Hi Gerhardus,

W dniu 16.10.2011 22:32, Gerhardus Geldenhuis pisze:
> Lastly is there any geological map symbol databases available?

Here is one.
http://freemapsymbols.org/svg/v1.2/simboli_geologici/

regards,
Robert
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Re: Creating Geological Maps

Alex Mandel-2
In reply to this post by Gerhardus Geldenhuis
On 10/16/2011 01:32 PM, Gerhardus Geldenhuis wrote:

>
> My first question is with regards to the png images that I am using. When I
> add these images as a raster layer they appear very dirty and when zooming
> in the detail is obscured as if someone has rubbed over it. At first I
> thought that the issue was jpeg compression which took away detail so I
> resaved the images as png files and double checked using various image
> viewers under Ubuntu that the image quality is up to scratch. So for some
> reason Quantum GIS is not displaying these images correctly how do I fix
> this?
>

Tiff is usually the best format to work with. If you can go back and
scan as tiff, make sure to do as high a dpi as you need (depending on
your needs 300-600 dpi+). You are correct JPEG will compress and ruin
your quality, converting jpeg to png will solve nothing if it's already
JPEG.

Just to check, do you have projection on-the-fly turned on? For best
image quality the image needs to be in it's native projection. Though in
this case it sounds like you just opened the image file to look at it.
How does it look in something like GIMP when you zoom in?

> Second question is how can I "align" this png file with with an actual
> co-ordinate system. I have marked 4 points on my paper maps and lines
> between these points that represent the UTM grid on which I worked and I
> would need to at least roughly align this image with the UTM grid.
>

Georeferencing plugin, this will turn your tiff into a GeoTiff, the same
as what you might get from preprocessed ASTER data. You can mark and
enter known coordinate locations and then warp the image to fit.

> Thirdly I am not sure how to draw on a new layer but still view my image as
> a template for the digitizing.
>
> I am more than happy to read any documentation and work through tutorials.
> What is lacking at the moment is the terminology to search for the correct
> things and experience. I am working through a number of tutorials but are
> still struggling a bit to connect A to B.
>
Read the manual on the QGIS website, create a new vector layer and
editing it can be over anything else you have loaded in the map view.
http://qgis.org/en/documentation/manuals.html

> I will eventually add some ASTER imagery but it is my understanding that
> these are in tiff format and contains extra information like spatial
> referencing. I suspect that if I can master the above then adding ASTER
> imagery will be easy.
>
> Lastly is there any geological map symbol databases available?
>
It's been discussed and some work has been done on it but nothing
comprehensive yet. If you have Images or Fonts of the symbols you want
you can easily convert them for use in QGIS.


> I would appreciate any pointers or brief/detailed outlines of the
> methodology I should be following to get best results.
>
> Best Regards
>
>


Enjoy,
Alex

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Re: Creating Geological Maps

Gerhardus Geldenhuis
On Sun, Oct 16, 2011 at 10:03 PM, Alex Mandel <[hidden email]> wrote:
On 10/16/2011 01:32 PM, Gerhardus Geldenhuis wrote:
Just to check, do you have projection on-the-fly turned on? For best
image quality the image needs to be in it's native projection. Though in
this case it sounds like you just opened the image file to look at it.
How does it look in something like GIMP when you zoom in?

Hi Alex
Many thanks for the reply!

No idea if I have project on-the-fly turned on, I could not see any reference to it in the project properties or options.
Native projection? I scanned the paper images and the scanner saved them as jpeg files. I then opened up the images in The Gimp rotated and aligned the to a drawing grid in Gimp because they were about 1 degree skewed. I had pencilled lines on the paper that represented UTM grid lines. I saved these as both jpg and png format both in lowest compression thus highest quality. Viewing either the jpg or png file in Gimp or Image Viewer is fine and if I zoom in to 1:1 scale the quality is perfect.
 

> Second question is how can I "align" this png file with with an actual
> co-ordinate system. I have marked 4 points on my paper maps and lines
> between these points that represent the UTM grid on which I worked and I
> would need to at least roughly align this image with the UTM grid.
>

Georeferencing plugin, this will turn your tiff into a GeoTiff, the same
as what you might get from preprocessed ASTER data. You can mark and
enter known coordinate locations and then warp the image to fit.

That sounds excellent I am going to try that now.
 

> Thirdly I am not sure how to draw on a new layer but still view my image as
> a template for the digitizing.
>
> I am more than happy to read any documentation and work through tutorials.
> What is lacking at the moment is the terminology to search for the correct
> things and experience. I am working through a number of tutorials but are
> still struggling a bit to connect A to B.
>
Read the manual on the QGIS website, create a new vector layer and
editing it can be over anything else you have loaded in the map view.
http://qgis.org/en/documentation/manuals.html

> I will eventually add some ASTER imagery but it is my understanding that
> these are in tiff format and contains extra information like spatial
> referencing. I suspect that if I can master the above then adding ASTER
> imagery will be easy.
>
> Lastly is there any geological map symbol databases available?
>
It's been discussed and some work has been done on it but nothing
comprehensive yet. If you have Images or Fonts of the symbols you want
you can easily convert them for use in QGIS.


A shame, I have send of an email to the British Geological Survey and see what they come back with. I might have access to the ArcGIS and could load the images database provided by the US Geological Survey. Not sure if ArcGIS would allow me to export it into something more usable. My google results turned up an email thread which suggested that there was some work done on supporting gdb files... 
 
Regards

--
Gerhardus Geldenhuis

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Re: Creating Geological Maps

Alex Mandel-2
On 10/16/2011 02:26 PM, Gerhardus Geldenhuis wrote:

> On Sun, Oct 16, 2011 at 10:03 PM, Alex Mandel <[hidden email]>wrote:
>
>> On 10/16/2011 01:32 PM, Gerhardus Geldenhuis wrote:
>> Just to check, do you have projection on-the-fly turned on? For best
>> image quality the image needs to be in it's native projection. Though in
>> this case it sounds like you just opened the image file to look at it.
>> How does it look in something like GIMP when you zoom in?
>>
>
> Hi Alex
> Many thanks for the reply!
>
> No idea if I have project on-the-fly turned on, I could not see any
> reference to it in the project properties or options.
> Native projection? I scanned the paper images and the scanner saved them as
> jpeg files. I then opened up the images in The Gimp rotated and aligned the
> to a drawing grid in Gimp because they were about 1 degree skewed. I
> had pencilled lines on the paper that represented UTM grid lines. I saved
> these as both jpg and png format both in lowest compression thus highest
> quality. Viewing either the jpg or png file in Gimp or Image Viewer is fine
> and if I zoom in to 1:1 scale the quality is perfect.
>
>
Redo that, and try to get a tiff or png from your scanner. Also there is
no need to manually rotate the image as georeferencing will take care of
that. The fewer saves/conversion along the process the better.

You probably do not have on-the-fly on since it's off by default.

>>
>>> Second question is how can I "align" this png file with with an actual
>>> co-ordinate system. I have marked 4 points on my paper maps and lines
>>> between these points that represent the UTM grid on which I worked and I
>>> would need to at least roughly align this image with the UTM grid.
>>>
>>
>> Georeferencing plugin, this will turn your tiff into a GeoTiff, the same
>> as what you might get from preprocessed ASTER data. You can mark and
>> enter known coordinate locations and then warp the image to fit.
>>
>
> That sounds excellent I am going to try that now.
>
>
>>
>>> Thirdly I am not sure how to draw on a new layer but still view my image
>> as
>>> a template for the digitizing.
>>>
>>> I am more than happy to read any documentation and work through
>> tutorials.
>>> What is lacking at the moment is the terminology to search for the
>> correct
>>> things and experience. I am working through a number of tutorials but are
>>> still struggling a bit to connect A to B.
>>>
>> Read the manual on the QGIS website, create a new vector layer and
>> editing it can be over anything else you have loaded in the map view.
>> http://qgis.org/en/documentation/manuals.html
>>
>>> I will eventually add some ASTER imagery but it is my understanding that
>>> these are in tiff format and contains extra information like spatial
>>> referencing. I suspect that if I can master the above then adding ASTER
>>> imagery will be easy.
>>>
>>> Lastly is there any geological map symbol databases available?
>>>
>> It's been discussed and some work has been done on it but nothing
>> comprehensive yet. If you have Images or Fonts of the symbols you want
>> you can easily convert them for use in QGIS.
>>
>>
> A shame, I have send of an email to the British Geological Survey and see
> what they come back with. I might have access to the ArcGIS and could load
> the images database provided by the US Geological Survey. Not sure if ArcGIS
> would allow me to export it into something more usable. My google results
> turned up an email thread which suggested that there was some work done on
> supporting gdb files...
>
> Regards
>
ESRI icons are all fonts, and can be converted using fontforge to svg.
Though I don't know anything about the licensing.

We are trying to work on more open sets, a preliminary list of things
that might help is here:
http://wiki.osgeo.org/wiki/OSGeo_map_symbol_set

The USGS symbols are available but need to be cut on and converted using
GIMP/Inkscape if you want scalable svg.

Thanks,
Alex

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Re: Creating Geological Maps

Alister Hood
In reply to this post by Gerhardus Geldenhuis
> Date: Sun, 16 Oct 2011 15:29:42 -0700
> From: Alex Mandel <[hidden email]>
> Subject: Re: [Qgis-user] Creating Geological Maps
> To: [hidden email]
> Message-ID: <[hidden email]>
> Content-Type: text/plain; charset=ISO-8859-1
>
> On 10/16/2011 02:26 PM, Gerhardus Geldenhuis wrote:
> > On Sun, Oct 16, 2011 at 10:03 PM, Alex Mandel
> <[hidden email]>wrote:
> >
> >> On 10/16/2011 01:32 PM, Gerhardus Geldenhuis wrote:
> >> Just to check, do you have projection on-the-fly turned on? For
best
> >> image quality the image needs to be in it's native projection.
Though in
> >> this case it sounds like you just opened the image file to look at
it.
> >> How does it look in something like GIMP when you zoom in?
> >>
> >
> > Hi Alex
> > Many thanks for the reply!
> >
> > No idea if I have project on-the-fly turned on, I could not see any
> > reference to it in the project properties or options.
> > Native projection? I scanned the paper images and the scanner saved
them as
> > jpeg files. I then opened up the images in The Gimp rotated and
aligned the
> > to a drawing grid in Gimp because they were about 1 degree skewed. I
> > had pencilled lines on the paper that represented UTM grid lines. I
saved
> > these as both jpg and png format both in lowest compression thus
highest
> > quality. Viewing either the jpg or png file in Gimp or Image Viewer
is fine
> > and if I zoom in to 1:1 scale the quality is perfect.
> >
> >
> Redo that, and try to get a tiff or png from your scanner. Also there
is
> no need to manually rotate the image as georeferencing will take care
of
> that. The fewer saves/conversion along the process the better.

Feel free to try scanning as tiff, but since the image you already have
displays clearly at 100% or in other image viewers, I doubt that will
solve the problem.
I think the problem is that the gdal provider in QGIS (this is what is
used to load raster image files) does not do antialiasing ("smoothing").
Raster antialiasing is particularly important for scanned maps.  I
thought there was an enhancement ticket for it, but I can't find it.
Does anybody else know?  Perhaps it was just discussed on one of the
lists.

> You probably do not have on-the-fly on since it's off by default.
> >>
> >>> Second question is how can I "align" this png file with with an
actual
> >>> co-ordinate system. I have marked 4 points on my paper maps and
lines
> >>> between these points that represent the UTM grid on which I worked
and I
> >>> would need to at least roughly align this image with the UTM grid.
> >>>
> >>
> >> Georeferencing plugin, this will turn your tiff into a GeoTiff, the
same
> >> as what you might get from preprocessed ASTER data. You can mark
and
> >> enter known coordinate locations and then warp the image to fit.
> >>
> >
> > That sounds excellent I am going to try that now.
> >
> >
> >>
> >>> Thirdly I am not sure how to draw on a new layer but still view my
image
> >> as
> >>> a template for the digitizing.
> >>>
> >>> I am more than happy to read any documentation and work through
> >> tutorials.
> >>> What is lacking at the moment is the terminology to search for the
> >> correct
> >>> things and experience. I am working through a number of tutorials
but are
> >>> still struggling a bit to connect A to B.
> >>>
> >> Read the manual on the QGIS website, create a new vector layer and
> >> editing it can be over anything else you have loaded in the map
view.
> >> http://qgis.org/en/documentation/manuals.html
> >>
> >>> I will eventually add some ASTER imagery but it is my
understanding that
> >>> these are in tiff format and contains extra information like
spatial
> >>> referencing. I suspect that if I can master the above then adding
ASTER
> >>> imagery will be easy.
> >>>
> >>> Lastly is there any geological map symbol databases available?
> >>>
> >> It's been discussed and some work has been done on it but nothing
> >> comprehensive yet. If you have Images or Fonts of the symbols you
want
> >> you can easily convert them for use in QGIS.
> >>
> >>
> > A shame, I have send of an email to the British Geological Survey
and see
> > what they come back with. I might have access to the ArcGIS and
could load
> > the images database provided by the US Geological Survey. Not sure
if ArcGIS
> > would allow me to export it into something more usable. My google
results
> > turned up an email thread which suggested that there was some work
done on
> > supporting gdb files...
> >
> > Regards
> >
> ESRI icons are all fonts, and can be converted using fontforge to svg.
> Though I don't know anything about the licensing.

You can use font symbols in QGIS, and the ESRI fonts are probably
installed with their free viewers... using them could well violate the
license though ;)

> We are trying to work on more open sets, a preliminary list of things
> that might help is here:
> http://wiki.osgeo.org/wiki/OSGeo_map_symbol_set
>
> The USGS symbols are available but need to be cut on and converted
using
> GIMP/Inkscape if you want scalable svg.
>
> Thanks,
> Alex

Alister
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Re: Creating Geological Maps

Jean-Claude Repetto-3
In reply to this post by Gerhardus Geldenhuis
Le 16/10/2011 22:32, Gerhardus Geldenhuis a écrit :
>
> Second question is how can I "align" this png file with with an actual
> co-ordinate system. I have marked 4 points on my paper maps and lines
> between these points that represent the UTM grid on which I worked and I
> would need to at least roughly align this image with the UTM grid.
>

Use the georeferencer plugin.

Jean-Claude
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Re: Creating Geological Maps

Jonathan Moules-2
In reply to this post by Gerhardus Geldenhuis
Hi Gerhardus,
        Just to clarify on image file formats a little:

JPEG - Best used with photos. You're correct that it loses quality when compressed. This is called "lossy compression".

PNG - Also commonly used with photos, the compression with this is lossless, so you can set it as high as you like and no quality will be lost.


Generally speaking while good for storing general imagery, the above two formats don't typically hold spatial information so aren't used in a GIS.

TIF (also TIFF) - There's about a trillion different types of TIF file format features. This is the file type that in the GIS world is commonly used to store raster imagery. There are others, but this one is the most supported, even if different aspects are supported by different applications.
By default they're uncompressed, but they can be compressed using a number of methods, LZW compression is a popular choice and is lossless. TIFs themselves don't always store spatial information but may come with a "world file" (tfw or tab format) which is a small text file which contains that information. Some TIFs do store spatial information within the TIF file itself and these are called "GeoTIFFs".
Some (geo)tiffs can also store "pyramids" - these make large rasters display faster when zoomed out.

Hopefully that clears things up a little.
Regards,

Jonathan




From:        Gerhardus Geldenhuis <[hidden email]>
To:        [hidden email]
Cc:        [hidden email]
Date:        16/10/2011 22:26
Subject:        Re: [Qgis-user] Creating Geological Maps
Sent by:        [hidden email]




On Sun, Oct 16, 2011 at 10:03 PM, Alex Mandel <tech_dev@...> wrote:
On 10/16/2011 01:32 PM, Gerhardus Geldenhuis wrote:
Just to check, do you have projection on-the-fly turned on? For best
image quality the image needs to be in it's native projection. Though in
this case it sounds like you just opened the image file to look at it.
How does it look in something like GIMP when you zoom in?


Hi Alex
Many thanks for the reply!

No idea if I have project on-the-fly turned on, I could not see any reference to it in the project properties or options.
Native projection? I scanned the paper images and the scanner saved them as jpeg files. I then opened up the images in The Gimp rotated and aligned the to a drawing grid in Gimp because they were about 1 degree skewed. I had pencilled lines on the paper that represented UTM grid lines. I saved these as both jpg and png format both in lowest compression thus highest quality. Viewing either the jpg or png file in Gimp or Image Viewer is fine and if I zoom in to 1:1 scale the quality is perfect.
 

> Second question is how can I "align" this png file with with an actual
> co-ordinate system. I have marked 4 points on my paper maps and lines
> between these points that represent the UTM grid on which I worked and I
> would need to at least roughly align this image with the UTM grid.
>

Georeferencing plugin, this will turn your tiff into a GeoTiff, the same
as what you might get from preprocessed ASTER data. You can mark and
enter known coordinate locations and then warp the image to fit.


That sounds excellent I am going to try that now.
 

> Thirdly I am not sure how to draw on a new layer but still view my image as
> a template for the digitizing.
>
> I am more than happy to read any documentation and work through tutorials.
> What is lacking at the moment is the terminology to search for the correct
> things and experience. I am working through a number of tutorials but are
> still struggling a bit to connect A to B.
>

Read the manual on the QGIS website, create a new vector layer and
editing it can be over anything else you have loaded in the map view.

http://qgis.org/en/documentation/manuals.html

> I will eventually add some ASTER imagery but it is my understanding that
> these are in tiff format and contains extra information like spatial
> referencing. I suspect that if I can master the above then adding ASTER
> imagery will be easy.
>
> Lastly is there any geological map symbol databases available?
>

It's been discussed and some work has been done on it but nothing
comprehensive yet. If you have Images or Fonts of the symbols you want
you can easily convert them for use in QGIS.



A shame, I have send of an email to the British Geological Survey and see what they come back with. I might have access to the ArcGIS and could load the images database provided by the US Geological Survey. Not sure if ArcGIS would allow me to export it into something more usable. My google results turned up an email thread which suggested that there was some work done on supporting gdb files... 
 
Regards

--
Gerhardus Geldenhuis
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Re: Creating Geological Maps

ves nikos
In reply to this post by Gerhardus Geldenhuis
On 10/16/2011 11:32 PM, Gerhardus Geldenhuis wrote:
> Second question is how can I "align" this png file with with an actual
> co-ordinate system. I have marked 4 points on my paper maps and lines
> between these points that represent the UTM grid on which I worked and I
> would need to at least roughly align this image with the UTM grid.
woo you did some old school job  - its really pain that stage, but after
the initial work the fun starts ;D


Now:
For that you need to georeference the rasters. having sheets (or
rasters) of data I've found the 'MapSheetAutoGenRef' plugin (3rd party
plugin) that supposedly auto georefs the rasters based on SHP files you
create along known grids.

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