Charts II: NGA - 2700 Charts

[cagney]

Originally Posted by Netsurfer

...
Just using the slightly skewed chart with the pixel coordinates and left the rotation to the presenting application (e.g. OpenCPN) or trying to rotate the chart before calibrating it?
My guess would be that the first one will be the better option - but just a guess.

Gunther

If the chart is so skewed, that it is obvious, and it is just a question of turning the picture some degrees, we should do so.
An example of a bad apple is 24385.
I can make the PLY follow the inner border with normal calculation, but the end result is still skewed. This can be corrected to a certain degree by setting SK=3.0, but then the chart can't be quilted.

Thomas

[LeaseOnLife]

Originally Posted by cagney

If the chart is so skewed, that it is obvious, and it is just a question of turning the picture some degrees, we should do so.
An example of a bad apple is 24385.
I can make the PLY follow the inner border with normal calculation, but the end result is still skewed. This can be corrected to a certain degree by setting SK=3.0, but then the chart can't be quilted.

Thomas

24385 looks pretty bad and should be turned a couple of degrees. But since we focus on simple charts, for now, I think we should just flag the skewed charts, to be worked on later, different process. We could detect this automatically: If the x positions don't match for a given latitude by some %, flag it. Same for y.

We could calculate the degrees of rotation needed, and apply this during the resize/color-reduction.


Out of office:
We head out of Port Louis and see some more of Mauritius, not sure about internet in the next anchorage.

• Region 9 is downloaded, stitched, uploaded, complete
• Region 6 is still missing 61601. Ruby and Python script fail. Probably has a missing tile. Maybe Allen's script and adding a white tile manually could do the job.
  .

Cheers

Dirk

[LeaseOnLife]

Originally Posted by LeaseOnLife

Region 9 is downloaded, stitched, uploaded, complete

Nonsense, I meant Region Misc.....

[Surveyor]

We could use some volunteers to help grab charts! I know there are alot of people looking at this thread and I am positive that there are people downloading charts but are not involved with the project.

This is an open invitation for those of you who are downloading at 100% resolution to please get involved with the group and share your data. We could really use the help and would greatly appreciate anything you provide.

For anyone that would like to help but are having a hard time with the scripts, feel free to message me and I will see if I can help. If I can do it, anyone can.

[allanpeda]

FYI,

I'm still chugging away on 5xxxx charts:
4shared folder - charts
If that is not of use, I am open to requests.

[Surveyor]

Allan are you re-grabbing the ones that were done previously at 75% ?

[allanpeda]

Originally Posted by Surveyor

Allan are you re-grabbing the ones that were done previously at 75% ?

No, 100%. I have been grabbing 5xxxx series files for the last few weeks, only recently did I mod my script to do it in a loop.

You prefer other numbers, let me know.

[Surveyor]

No thats not what I meant. Sorry if I confused you...and everyone else.

I am pretty sure that some of the region 5 charts that were uploaded early last week by someone else were grabbed at 75%. I will try to find my clue to why I think this in the thread. I know its there.

It doesnt matter I guess. Gunther can tell what is what by looking at the file size.

[Surveyor]

Originally Posted by bcn

52039 to 52143 are uploaded.

As we are in "stand-by" about compressing/creating the kap:s I will start now to download the 53011 - 53133 range.

In our case download/stitch at 75% Q is about 50min/file

Cheers

Hubert

Found it.

[LeaseOnLife]

Originally Posted by allanpeda

No, 100%. I have been grabbing 5xxxx series files for the last few weeks, only recently did I mod my script to do it in a loop.

You prefer other numbers, let me know.

Allan your pngs at 100% quality, should be OK!

But you will have to change the names before uploading to the ftp server. No prefix, no chart name, just the chart number. Like 53750.png

Thanks to MooseMoney, we now have a common server to store all the files. Gunter has put together instructions on how to upload to the FTP server http://opencpn.info/en/nga-charts-upload-files

Keep downloading and stitching, but also, please upload the files to the ftp server.

oh, one more, please add a comment to
http://opencpn.info/en/nga-charts-status-5
telling us which charts you are getting, to avoid duplicate work. You will have to register first...

Dirk

[jonasaberg]

I had just a limited time to get the ruby script going and gave up...

I downloaded Ruby from Downloads
I downloaded Cagneys hard-coded script from http://www.cruisersforum.com/forums/...tml#post720966

I then clicked on start, choose "start command prompt with ruby"

I tried the script and failed. I then read the script and it seems it needs four add ons.
I managed to install Nokogiri by writing
gem install nokogiri
but I fail to install the other three:
'open-uri'
'rubygems'
and
'fileutils'

The fileutils seem to be a part of the dev kit, here I ran out of time... will be away for two weeks and had some hope of getting a script up and running to have my pc at work while away but it will have to wait.

Could maybe someone write a short "Howto" that includes how to get the ruby script up and running including what and where to download from?
I think that would greatly help to get more contributors.

The "Howto" should preferably be found at
NGA Charts Status at OpenCPN.info (English)
or some other easy to find place. I tried to browse through the thread to find this but is already getting to be too long for this...sorry.

Also, for it to be really usable it would be good to:
- be able to download a text list of the chart numbers in a region.
- use these as an argument in a batch file
to avoid having to feed the charts numbers manually.
It would also be good with a windows versions of the batch file...

The more automated, the easier to find many contributors.

Thanks.

/J

[Surveyor]

Originally Posted by jonasaberg

I had just a limited time to get the ruby script going and gave up...

I downloaded Ruby from Downloads
I downloaded Cagneys hard-coded script from http://www.cruisersforum.com/forums/...tml#post720966

I then clicked on start, choose "start command prompt with ruby"

I tried the script and failed. I then read the script and it seems it needs four add ons.
I managed to install Nokogiri by writing
gem install nokogiri
but I fail to install the other three:
'open-uri'
'rubygems'
and
'fileutils'

The fileutils seem to be a part of the dev kit, here I ran out of time... will be away for two weeks and had some hope of getting a script up and running to have my pc at work while away but it will have to wait.

Could maybe someone write a short "Howto" that includes how to get the ruby script up and running including what and where to download from?
I think that would greatly help to get more contributors.

The "Howto" should preferably be found at
NGA Charts Status at OpenCPN.info (English)
or some other easy to find place. I tried to browse through the thread to find this but is already getting to be too long for this...sorry.

Also, for it to be really usable it would be good to:
- be able to download a text list of the chart numbers in a region.
- use these as an argument in a batch file
to avoid having to feed the charts numbers manually.
It would also be good with a windows versions of the batch file...

The more automated, the easier to find many contributors.

Thanks.

/J

You were very close. Very very close. A bit more google and I think you would have hit the jackpot just like I did. Automated downloads probably isnt going to happen other than the scripts that already exist in one form or another. I could be wrong about that though.

The Python script is fast compared to the others. The batch process breaks often and is a PITA because of the resulting file names. The Ruby script is slow as but very stable and can grab what python cannot in most cases but not all.

If you were not going away for two weeks I would attempt to explain further. Fair winds!

[Surveyor]

Situation;

A 3000+- tile chart is missing a tile.
The tile is within border/map area.
The size of the tile can be determined.
The tile does or does not contain vital nav info.

How should we proceed?

I assume that we would create a tile with a specific color that would be obvious yet not create a "color burden". It would be a shame for a chart with 0.003 of its total area in question to be cast aside. What are your thoughts?

[LeaseOnLife]

Originally Posted by jonasaberg

Could maybe someone write a short "Howto" that includes how to get the ruby script up and running including what and where to download from?
I think that would greatly help to get more contributors.

Agreed, 100%

I started here, on the ngacharts wiki (can be moved later to opencpn.info):
https://github.com/ngacharts/ngacharts/wiki

How to use the ruby script and how to feed chart numbers from a text file:
https://github.com/ngacharts/ngachar...fy-ruby-script

Listings with chart numbers per region:
https://github.com/ngacharts/ngachar...mber-by-Region

Make sure you announce the block you are downloading, stitching and uploading on
http://opencpn.info/en/

Can the other contributors please add content to:
https://github.com/ngacharts/ngachar...stitch-scripts
for the other scripts (php, python, perl....)

Also add any installation help, pre-requisites, etc

[LeaseOnLife]

Originally Posted by Surveyor

Situation;

A 3000+- tile chart is missing a tile.
The tile is within border/map area.
The size of the tile can be determined.
The tile does or does not contain vital nav info.

How should we proceed?

I assume that we would create a tile with a specific color that would be obvious yet not create a "color burden". It would be a shame for a chart with 0.003 of its total area in question to be cast aside. What are your thoughts?

I suggest an all black tile to identify/show a missing piece. I think allen's perl script would be best to pick up pieces like this, the stitching can be re-run on previously downloaded tiles.