Scanning and calibrating paper maps for Oziexplorer
Submitted: Saturday, Apr 19, 2008 at 22:46
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Member - Tim - Stratford (VIC)
Evening all,
I'm after a few tips regarding the scanning of paper maps to digital format with the intention of calibrating them and using them on OziExplorerCE (PDA).
I've done quite a few - started out photocopying them, then scanning at A4. I had a few
grid lines out by a fair margin and a few roads/tracks wouldn't align.
Plan B - photocopying the maps but reducing the size from A3 to A4, then scanning them. The idea being less scanning required - hence less errors. This 'sort' of worked but some scans ended up being approx 1% out - ie gridlines and tracks wouldn't match up.
Has anyone successfully scanned large paper maps and had a seamless end product? I'm still looking out for a large scanner at a printing business that could do a map in one pass - but so far I've only found A3 and the cost is prohibitive.
Any suggestions appreciated!
Tim.
Reply By: Member - joc45 (WA) - Saturday, Apr 19, 2008 at 23:15
Saturday, Apr 19, 2008 at 23:15
Hi Tim, I haven't tried OziMapmerge, but I did some A1-sized maps a few years back.
I tried my Canon Photostitch software, which merges photos, and it got totally confused, so gave up on that. I ended up using a conventional photo-editor program, making each scanned A4 page overlap, and putting a faded edge on each page. Using the rotate function, I managed to align each page quite
well, with minimum error. An A1 map used about 10 A4 scanned pages. I made sure that all 10 were on the final page and aligned before merging the lot.
Geez, it took some nights though!
Gerry
AnswerID:
299369
Reply By: The Explorer - Sunday, Apr 20, 2008 at 02:23
Sunday, Apr 20, 2008 at 02:23
Hello
One method is describe here
Scanning Maps
Before proceeding too far would suggest seeking out other options as it can be very time consuming to get good result. Maps of Vic, ready to go with Oziexplorer are available free from the gps australia
forum...and other maps for various areas are available at cost, see exploroz
shop. Suppose it depends how much spare time you have and if the map/maps you want are already done.
If the map you want is not around in digital fromat next best option is to get it scanned properly. You can get full size maps scanned in
Perth for ~$30 a pop, suspect other cities would have similar
services. Sure beats stuffing around for hours at
home for maybe second rate result.
Cheers
Greg
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AnswerID:
299382
Reply By: chocolate teapot - Sunday, Apr 20, 2008 at 07:02
Sunday, Apr 20, 2008 at 07:02
Hi Tim
like jock45 I scanned the maps in a4 chunks and merged them using - bit of a fiddle and a few brain spasms - but it works.
You end up with a large digital map you then align in the normal way in a number of points with ozi.
Please don't be offended but I would suggest that your way would introduce too many errors - remember that when you photocopy there are al sorts of distortions from each stage - the optics, the electronics and then putting them all back together - the merge is pretty simple with.
Having done it I would suggest that if you can buy the maps of interest in digital form at a reasonable price that is the way I would go.
Overall assessment of my method - possible but difficult and time consuming.
Hope this helps
AnswerID:
299388
Follow Up By: Member - joc45 (WA) - Sunday, Apr 20, 2008 at 11:20
Sunday, Apr 20, 2008 at 11:20
Hi Choc Teapot,
Yes, I found that the edges of the scan were the worst for distortion, usually where the map curls up on the edge of the scanner. So I used a smaller part of the scan, discarding the edges, and fuzzing the new edges. This way, the overlaps of the individual maps looked seamless.
I eventually got
mine pretty error-free, with usually only about a mm error on the merges. Took some trial and error, tho.
Panavue program stitches them
well, but it costs. The trial version leaves a "Panavue" watermark on the image.
But if, as Greg (Explorer) says, you can get an A1 map scanned for $30, this looks like a better way than spending an evening per map scanning the damn thing.
Gerry
FollowupID:
565579
Reply By: Member - Roscoe ET (QLD) - Sunday, Apr 20, 2008 at 09:49
Sunday, Apr 20, 2008 at 09:49
Hi Tim,
I take it that the end result of what you are doing is to use the maps on a laptop with GPS input using OziExplorer?
If this is the case it seems to me you are going about this in a laborious way with all this photocopying and scanning.
Have you thought about purchasing the Natmap Raster Premuim disc. These maps are exact digital copies Geoscience Australia's Natmap topographic maps and can be used for real-time navigation with GPS.
The OziExplorer program will allow you to work with these digital maps.
I have both the Natmap Raster Premium disc and the OziExplorer program. I haven't seriously created anything yet just had a bit of a play around but I'm pretty sure that what you are trying to do can be achieved by using Natmap digital mapping. I'm sure you won't have any issues with
grid lines etc misaligning.
AnswerID:
299403
Follow Up By: Member - joc45 (WA) - Sunday, Apr 20, 2008 at 11:29
Sunday, Apr 20, 2008 at 11:29
Hi Roscoe,
it depends on what you want and what's available. While a lot of hi-res maps are available commercially (or free) for eastern states, in WA, you can buy the digitized DOLA 50k maps ok (thanks to Explorer), but the excellent CALM 50k maps of the SW of WA are only available in paper form, not digitized (or were when last I checked).
I spent many weeks of nights scanning my large collection of CALM maps, but it was worth it.
Gerry.
FollowupID:
565581
Follow Up By: Member - Roscoe ET (QLD) - Sunday, Apr 20, 2008 at 13:47
Sunday, Apr 20, 2008 at 13:47
Gerry,
The Rasta mapping I have was last updated on 06.03.07. I take it from what you are saying the CALM maps show more or better detail than the topographic Raster map?
Mate I'm not disputing what you're saying I'm just curious as to the difference between the two as the Raster map does show extensive detail. I've been printing off hard copies of areas that I have travelled and used them last year when I was over your way.
As an example I went across from Mt Augustus to Paraburdoo and it was spot on I knew exactly where I was at all times.
Eventually I want to get a laptop with GPS software and I was going to use Raster maps but if there's something better then I'd consider it.
Surely there's got to be a better way than spending hours of scanning in this day and age but I suppose in due course more and more mapping will become available on disc.
FollowupID:
565593
Follow Up By: Member - joc45 (WA) - Sunday, Apr 20, 2008 at 23:25
Sunday, Apr 20, 2008 at 23:25
Hi Roscoe,
I'm assuming you are referring to the Natmap 250 Mosaic map. My version is about 3 years old. This has pretty good detail, but the 50k CALM maps of the SW show every fire trail, tree blaze, etc, which the Natmap, or even the 50k DOLA maps don't show.
But I wouldn't be using a 50k map out in the country you describe.
Actually, I was using the 250k Natmap driving from Minilya to Mt Augustus (WA), and in one place, for several kilometres, the map showed the road going where it had never gone before. Thought it might have shown the old road, but there were thick trees where the map showed - never ever was a road there.
Interestingly, I have old army maps of the Nullarbor dating around 1960 which are more accurate for some tracks than the current Natmap 250k!
cheers,
Gerry
FollowupID:
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Follow Up By: Member - Roscoe ET (QLD) - Monday, Apr 21, 2008 at 09:09
Monday, Apr 21, 2008 at 09:09
Thanks for that Gerry had a feeling the extra detail might have been fire
trails and the like. Those old army maps are pretty good if you can get hold of them.
Same with the marine ones from the navy, a friend of
mine in
Gladstone got hold of one for the area out off the coast there, showed a few drop offs and small reefs that weren't on the normal chart...suffice to say we kept them to ourselves!!!
FollowupID:
565766
Reply By: Member - Jim R (ACT) - Monday, Apr 21, 2008 at 09:22
Monday, Apr 21, 2008 at 09:22
For what its worth, I have tried most of the approaches described in previous responses with varying degrees of success. MapMerge is a very ggod tool but the end result depends VERY heavily on the accuracy with which the component maps have been calibrated.
The best results I have achieved, which really did result in a seamless join between portions was to use a product called Panvue Image Assembler which was not terribly expensive but gives EXCELLENT results. It readily takes account of slight misalighnments in your scanning (a problem with most normal image editing software) and can even cope with images of different scales.
One important thing is to convert any resulting image (which can be VERY large) into OZF3 format so that it will page into memory with OziExplorer rather than try and load in totality as many image formats do.
AnswerID:
299587
Follow Up By: Member - joc45 (WA) - Monday, Apr 21, 2008 at 12:48
Monday, Apr 21, 2008 at 12:48
Hi Jim,
Yes, I've tried the trial version of Panavue, and it works
well, warping the image slightly if necessary to match the adjoining page to be merged, so that the end result is a seamless join. Would recommend it.
My Canon Photostich software which came with my digital camera does a similar thing (in fact it does a brilliant job in merging photos, including warping and shifting the colours to match) but it seemed to get totally confused using maps with just a few colours. The end result was a mangled mess!
Gerry
FollowupID:
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Follow Up By: Member - Jim R (ACT) - Monday, Apr 21, 2008 at 14:10
Monday, Apr 21, 2008 at 14:10
Gerry,
The thing I like about panavue was the ability to help it out by desgnating points on overlapping maps that coincide. By doing this I have found all joins to be totally invisible.
Jim
FollowupID:
565806
Follow Up By: Member - joc45 (WA) - Monday, Apr 21, 2008 at 22:54
Monday, Apr 21, 2008 at 22:54
Yes, even Panavue gets it wrong occasionally, but being able to designate points that coincide allows Panavue to pull the scans together properly. Something that Canon's Photostitch couldn't do.
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