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Cellular forums Home > Archive > GPS > June 2007 > What software to use to create maps?
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What software to use to create maps?
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| Marcus Fox 2007-05-29, 10:33 am |
| What I want to do is scan in some paper maps - now these are quite large so
I will have to tile the images and drag them into position - what software
will easily work with large jpegs? I can't seem to do this in Irfanview.
Marcus
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| Keith Sheppard 2007-06-01, 7:33 am |
| Marcus
There are two ways to stitch map images. You can do it visually using a
panorama stitcher designed for digital photos. This is quick and easy but
not very accurate for mapping purposes. Also errors are cumulative. If you
stitch several tiles together there is likely to be a significant positional
error between the first and the last.
The second way is to stitch images geographically. To do this you need to
calibrate each image separately then use a mapping program, which is aware
of the calibration, to do the stitching based on each tile's geographical
position. This is more time consuming because you need to calibrate each
image but produces much more accurate results.
My own MapMan application (http://www.mapman.org.uk) has the ability to
stitch calibrated map tiles geographically. MapMan is free for the basic
feature set but map stitching is classified as an advance feature. This
means you can try it free of charge for 30 days. After that, if you decide
you like the product then a small one-off licence payment will provide
permanent access to all licenced features.
Regards
Keith.
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| Marcus Fox 2007-06-01, 3:33 pm |
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"Keith Sheppard" <keith.sheppard@tesco.net> wrote in message
news:LUS7i.15166$xU4.9188@newsfe1-gui.ntli.net...
> Marcus
>
> There are two ways to stitch map images. You can do it visually using a
> panorama stitcher designed for digital photos. This is quick and easy but
> not very accurate for mapping purposes. Also errors are cumulative. If
you
> stitch several tiles together there is likely to be a significant
positional
> error between the first and the last.
>
> The second way is to stitch images geographically. To do this you need to
> calibrate each image separately then use a mapping program, which is aware
> of the calibration, to do the stitching based on each tile's geographical
> position. This is more time consuming because you need to calibrate each
> image but produces much more accurate results.
>
> My own MapMan application (http://www.mapman.org.uk) has the ability to
> stitch calibrated map tiles geographically. MapMan is free for the basic
> feature set but map stitching is classified as an advance feature. This
> means you can try it free of charge for 30 days. After that, if you
decide
> you like the product then a small one-off licence payment will provide
> permanent access to all licenced features.
The map is printed in such a way that each map tile would have only one
calibration point printed on it, the reason for wanting to stitch the tiles
together beforehand is to have a number of calibration points on the
finished image. One of the issues I am having is I cannot get the pages to
lie perfectly flat, even though it is a folded map, rather than one in a
book. Consequently, the images may line up in one axis but not another. Also
in some cases, the images may be slightly rotated, perhaps less than a
degree, in which case the tiles do not line up at all.
Marcus
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| Keith Sheppard 2007-06-04, 4:33 am |
| >>The map is printed in such a way that each map tile would[color=darkred]
MapMan requires a minimum of two calibration points per tile (unless you can
guarantee that the map is perfectly oriented with North up the page). Could
you not extrapolate a second calibration point by careful measuring?
[color=darkred]
If you can get the tiles calibrated, MapMan will handle rotations for you.
[color=darkred]
That I can't help you with. MapMan (and, I suspect, most other mapping
packages) does assume that NS and EW are perpendicular to each other.
Keith
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