Scanning charts for SeaClear

[nigelmercier]

I've just bought an A3 scanner to make it easy to scan charts into SeaClear. I note that the scanning instructions are a bit dated, when PC memory was more limited. My scanner can do about 300-600 dpi native, so is it worth using say 300 dpi?

Any other tips would be appreciated.

BTW, it occurs to me that a lot of people are going to be scanning the same charts (mine are the Admiralty Croatia Folio). There must be a way to share these scans that doesn't infringe copyright?

 

[st599]

Scanning them in in the first place infringes copyright, So I can't see how sharing them wouldn't.

 

[shmoo]

300 pdi works fine for seaclear. A3 300 dpi bmp files are pretty big though - about 55Mb. By the time they are converted to WCI they get much smaller: just a few Mb. MAKE SURE THE SCANNER PRESERVES ASPECT RATIO: there may be an option.

Sharing would violate copyright, as would scanning, so this is not an incitement to do either.

 

[Guest]

Technically - scanning is infringing copyright ... but it is generally accepted that if you possess the originals the scans / copies are taken from - you will be ignored. I know this from DVD's, cassettes etc. and Customs actions when found in my bags .. BUT as Customs told me - I must be able to produce the originals !

As to sharing - NO NO NO ... having been involved in a sharing ring some time ago - I can say that UKHO and other Charting people are not amused !!

OK - onto scanning .... so many people adbvise Panavue and other programs ... after all the years I've done - using A4 scanners - I prefer Photoimpact - this combines both scanning and stitching into one program ... no watermarks ... no fiddling about ... you can have a sheet up to cut and paste to as well the scanned sections as you scan in etc. Makes the whole process so much more easier.

If I can help in anyway ... PM me .. Seaclear is a good program and serves well.

As to resolution ... in fact going up too high in resolution does not give anything really except increased file size .. when you convert to WCI - it converts to default Seaclear res. effectively.

 

[nigelmercier]

Thanks for the tips. What is the SeaClear resolution?

As to "sharing", I was envisaging a situation where somebody sends their charts, or a copy thereof with a newspaper front page, to someone who has already scanned them.

 

[Guest]

the res is relative ... it's not actual in terms like the scanned jpg etc.

EG - try - it scan a bit of chart and do it at 2 different levels ... say 150 and then 300 .. convert both to WCI - using different names of course ... and see if any difference - you will likely find very slight if any.

Sharing is a no-no ...

What people do behind closed doors is another matter ......

 

[Guest]

Before scanning ... mark crosses on the chart with Lat and Long written by side ..... also if you know the actual scan borders - you can also draw on alignment lines ..

Then when you scan and calibrate you have instant points to use without reference back to paper original. The alignment lines help you stitch sections back to larger coverage ... etc.

 

[nigelmercier]

Thanks for the tips, but I'm rather hoping that Auto Align in Photoshop CS3 will stitch them together for me. It certainly worked when I did a test - almost spooky!

It would even distort them to fit (not needed) and create a gradient mask to blend them, but I think I'll draw this myself.

Have a look here: http://www.adobe.com/go/vid0014 and prepare to be a bit scared!

 

[KCS]

You can only copy up A4 size any bigger and it breaks the copyright rules.

No sharing either I'm afraid

 

[Ruffles]

[ QUOTE ]
Have a look here: http://www.adobe.com/go/vid0014 and prepare to be a bit scared!

[/ QUOTE ]

That is indeed scary. Real life is no longer to be trusted.

 

[Robin2]

Its very unlikely that the chart is printed at 300dpi. According to a photo-editing book that I have high quality magazine art is only at 175 dpi.

The resolution of your scan is not really important. Try some low res scans at, say, 100dpi and see how it looks when you zoom in using SeaClear. Use the lowest resolution that gives you satisfactory visual detail.

The accuracy of navigation depends only on the "square-ness" of the scan - in other words does a 10x10 square cover the same area everywhere on the chart. Your A3 scanner should work perfectly. And, of course, the care you take in calibrating the charts - very easy to make mistakes.

I haven't used SeaClear - I was using OziExplorer which would automatically move on to the next chart. That meant I did not have to stitch the charts together.

One of the advantages I found from scanned charts was that I could zoom them up to a level where I could read the fine detail.

I gave up on scanned charts mainly because it was a real pain to scan a large area such as the south coast of Ireland because the coastline extends diagonally southwards as you move west.

And I gave up on bought raster charts because they are so expensive compared with C-map.

 

[TheBoatman]

Nigel
I never did get seaclear to work for me despite your considerable efforts.

Peter.

 

[nigelmercier]

OK, I've done all the scans. I've got 3 scans of each chart (the ends, plus an overlap). I have another question.

Although I can stitch them in CS3, something occoured to me: why do they need to be stitched at all? Each image is calibrated in MapCal, so is there a reason they need to be stitched?

 

[Guest]

Stitched ... none whatsoever if the area is reasonable .. just saves loading up next chartlet when you reach end of one ..

It is actually better to have smaller sections than one large job - as load up time is substantially reduced ...

 

[Guest]

We can try again ? It really is simple once you get it sorted - then you wonder what all the fuss was about !

 

[Guest]

[ QUOTE ]
You can only copy up A4 size any bigger and it breaks the copyright rules.

No sharing either I'm afraid

[/ QUOTE ]

Never heard that one ... about only A4 ...

Strange that Maptech and various wiull allow you to print charts of from the charting s/ware at size your printer can handle .. so if you are lucky and have an A3 printer - how can that be ?

As I have been told when a group I was in was involved in dispute over chart sharing / scanning etc. - it was accepted that if you had the original chart you could copy it for PERSONAL use only and no mention was ever made of size. But it was said that Copyright technically allows NO copy or scans.

 

[nigelmercier]

I've actually found a reason to stitch them! When calibrating, the approximate positions are pre-entered, so you don't have to enter so much manually if you only have one image to deal with.

OK, more questions:

I've done a test chart, copied it to the default folder, and updated the database. However, I don't know how to select it (remember I'm not actually "there").

Eventually I would like to export the WCI charts to BSB4 format, or another format that can be read by Maptech Chart Navigator. Any suggestions how to do this?

 

[shmoo]

(at least) two ways:

File | Chart | List all and select the chart you want or

Scan an atlas page of, say, whole of Europe, turn on outlines (with File | Chart | Outlines). You will be "on" the Europe chart wherever you are (in Europe, obviously) and the area of your other charts show up as red outlines

 

[Guest]

[ QUOTE ]
I've actually found a reason to stitch them! When calibrating, the approximate positions are pre-entered, so you don't have to enter so much manually if you only have one image to deal with.

<span style="color:blue"> True - fair point. </span>

OK, more questions:

I've done a test chart, copied it to the default folder, and updated the database. However, I don't know how to select it (remember I'm not actually "there").

<span style="color:blue"> In chart window in Seaclear - right click and then via chart ... choose the one you wish to display ... </span>

Eventually I would like to export the WCI charts to BSB4 format, or another format that can be read by Maptech Chart Navigator. Any suggestions how to do this?

<span style="color:blue"> Sorry - not possible ... not even to BSB earlier versions either ... </span>


[/ QUOTE ]

 

[nigelmercier]

[ QUOTE ]

Eventually I would like to export the WCI charts to BSB4 format, or another format that can be read by Maptech Chart Navigator. Any suggestions how to do this?

<span style="color:blue"> Sorry - not possible ... not even to BSB earlier versions either ... </span>


[/ QUOTE ]
Rats! I kind of assumed this would be possible.

OK, so is there any chart calibration software that will allow me to create BSB charts?