[Qgis-user] How do I register a Google Map?

[Mike Keelan]

Thanks James,

I got through the geo-referencing operation and  it did generate a new 
modified layer based on my .jpg.  However the new layer is badly 
distorted/stretched, (I used 4 coordinate Garmin GPS reference points), 
and it is not in the right location.  I can only find it by zooming to 
that layer extent.  I'm wondering if my coordinate data from my Garmin 
is consistent with what the geo-referencing program uses?  My Garmin 
data is xx.xxxxxx and it uses negative numbers to represent East instead 
of West.  Or, might there be an accuracy issue?

I know my Garmin way-point data is good because it overlays on my Ortho 
almost perfectly as a separate layer.

Mike K

On 2/3/2014 8:28 PM, James Wood wrote:
> Mike,
> Here is a good tutorial overview of the georeferencing tool in QGIS:
> http://qgis.spatialthoughts.com/2012/02/tutorial-georeferencing-topo-sheets.html
>
> If the image is not in coordinate space, it will not line up with your 
> other data. so this operation will be necessary.
>
> Also, just as a side, I would think that an export from Powerpoint 
> would degrade image quality (depending on the original). I would look 
> at and maybe try for future use The Gimp (which is an open source, 
> free Photoshop-type application). It will give you more control on 
> export of not only various output formats but also pixel and color 
> depth, and the like. The official site is http://www.gimp.org/.
>
> Best Regards,
> James
>
>
> ------------------------------------------------------------------------
> Date: Mon, 3 Feb 2014 19:59:14 -0500
> From: tmike.elhoa at comcast.net
> To: tech at wildintellect.com; etourigny.dev at gmail.com
> CC: qgis-user at lists.osgeo.org
> Subject: Re: [Qgis-user] How do I register a Google Map?
>
> OK, I installed the Open Layers plugin and it works very nice but it 
> won't do what I need, so let me be more specific and see if there 
> might be a remedy.
>
> The contour lines that I want were actually obtained using a hand held 
> Garman GPS.  The Garman data was overlaid on the Google map, (with 
> water depths),  special integration,  then that map was exported as a 
> Jpeg, then imported to PowerPoint where a visual interpolation was 
> done to make the final set of contour lines for the various lake water 
> depths.
>
> My desire is the _digitize_ these contour lines as a set of separate 
> layers. ie 5' deep, 10' deep, etc.  There are many good uses for these 
> layers,  but they must be accurate as to location and size.  I don't 
> think I necessarily need spacial info on the "map"/Jpeg if I can get 
> the whole map in the right position, and size, so I can do the 
> digitizing (which would then have the spacial info). Then I can 
> discard the Jpeg.
>
> Is it hopeless?
>
> Mike K
>
>
>

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