Ice Charts via SailDocs Or Other Low-Res Source?

[conachair]

Also saved as jpg & png , same file names with .jpg , .png added >
https://www.pythonanywhere.com/user/...hart_0.pdf.jpg

Tried in the weatherfax opencpn plugin, the polar mapping messed the image to unreadable but the mercator mapping might be useful, so small an area it's not skewed too much.

File sizes are much smaller >

chart_0.pdf
2018-07-08 14:59 275.5 KB
chart_0.pdf.jpg
2018-07-08 14:49 72.0 KB
chart_0.pdf.png
2018-07-08 14:59 126.9 KB

[conachair]

And a few more lines of code, now saving a smaller png and jpg. Not great quality but readable just about if time downloading is too long. PNG file size got bigger!

chart_0.pdf
2018-07-08 15:59 275.5 KB
chart_0.pdf.jpg
2018-07-08 15:59 72.0 KB
chart_0.pdf.png
2018-07-08 15:59 126.9 KB
chart_0.pdf.small.jpg
2018-07-08 15:59 35.3 KB
chart_0.pdf.small.png
2018-07-08 15:59 228.7 KB
chart_1.pdf
2018-07-08 15:59 742.8 KB
chart_1.pdf.jpg
2018-07-08 15:59 186.9 KB
chart_1.pdf.png
2018-07-08 15:59 289.7 KB
chart_1.pdf.small.jpg
2018-07-08 15:59 87.1 KB
chart_1.pdf.small.png
2018-07-08 15:59 626.0 KB
chart_2.pdf
2018-07-08 15:59 271.9 KB
chart_2.pdf.jpg
2018-07-08 15:59 69.7 KB
chart_2.pdf.png
2018-07-08 15:59 124.8 KB
chart_2.pdf.small.jpg
2018-07-08 15:59 34.2 KB
chart_2.pdf.small.png
2018-07-08 15:59 222.4 KB
chart_3.pdf
2018-07-08 15:59 753.8 KB
chart_3.pdf.jpg
2018-07-08 15:59 185.6 KB
chart_3.pdf.png
2018-07-08 15:59 290.0 KB
chart_3.pdf.small.jpg
2018-07-08 15:59 86.5 KB
chart_3.pdf.small.png
2018-07-08 15:59 624.4 KB
chart_4.pdf
2018-07-08 15:59 297.3 KB
chart_4.pdf.jpg
2018-07-08 15:59 75.9 KB
chart_4.pdf.png
2018-07-08 15:59 137.6 KB
chart_4.pdf.small.jpg
2018-07-08 15:59 36.7 KB
chart_4.pdf.small.png
2018-07-08 15:59 244.5 KB
chart_5.pdf
2018-07-08 15:59 844.2 KB
chart_5.pdf.jpg
2018-07-08 15:59 203.3 KB
chart_5.pdf.png
2018-07-08 15:59 314.7 KB
chart_5.pdf.small.jpg
2018-07-08 15:59 91.9 KB
chart_5.pdf.small.png
2018-07-08 15:59 691.7 KB
chart_6.pdf
2018-07-08 15:59 297.0 KB
chart_6.pdf.jpg
2018-07-08 15:59 75.0 KB
chart_6.pdf.png
2018-07-08 15:59 137.8 KB
chart_6.pdf.small.jpg
2018-07-08 15:59 36.4 KB
chart_6.pdf.small.png
2018-07-08 15:59 243.5 KB
chart_7.pdf
2018-07-08 15:59 295.3 KB
chart_7.pdf.jpg
2018-07-08 15:59 73.7 KB
chart_7.pdf.png
2018-07-08 15:59 136.4 KB
chart_7.pdf.small.jpg
2018-07-08 15:59 35.4 KB
chart_7.pdf.small.png
2018-07-08 15:59 238.0 KB
chart_8.pdf
2018-07-08 15:59 331.6 KB
chart_8.pdf.jpg
2018-07-08 15:59 81.6 KB
chart_8.pdf.png
2018-07-08 15:59 147.3 KB
chart_8.pdf.small.jpg
2018-07-08 15:59 38.3 KB
chart_8.pdf.small.png
2018-07-08 15:59 266.2 KB
chart_9.pdf
2018-07-08 15:59 355.5 KB
chart_9.pdf.jpg
2018-07-08 15:59 85.0 KB
chart_9.pdf.png
2018-07-08 15:59 156.9 KB
chart_9.pdf.small.jpg
2018-07-08 15:59 39.7 KB
chart_9.pdf.small.png
2018-07-08 15:59 279.9 KB

[Dockhead]

Originally Posted by conachair

Also saved as jpg & png , same file names with .jpg , .png added >
https://www.pythonanywhere.com/user/...hart_0.pdf.jpg

Tried in the weatherfax opencpn plugin, the polar mapping messed the image to unreadable but the mercator mapping might be useful, so small an area it's not skewed too much.

File sizes are much smaller >

It's very kind of you to do this! I was not able to get on there, but I'll try again tomorrow when I have decent Internet.

[conachair]

Originally Posted by Dockhead

It's very kind of you to do this! I was not able to get on there, but I'll try again tomorrow when I have decent Internet.

Oops, doesn't work!

Hopefully will in a minute when I sort out getting round the log on..

[hellosailor]

I' seeing the usual conflicting results on the web when I ask "Can html use wildcard characters?" but among them is:
https://stackoverflow.com/questions/...card-character

where the last post indicates that you can at least use a wildcard for the contents of a subdirectory. So if those files are being placed in one subdirectory, and it is a matter of simply one file being replaced with a newly named one every time?

Then it would seem that you can use HTML to simply call for whatever is in the directory.

If not, then there are php and other scripts that can search for the incrementing file names, presuming they are based on the numeric timestamps.

I'd also think a suggestion to the agency, letting them know that some folks need to reach out and robotically grab the file, might result in an even simpler change at their end, i.e. they could simply overwrite one particular file/folder every time the new one is posted, and leave that as a resource for mariners.

[conachair]

Originally Posted by conachair

Oops, doesn't work!

Hopefully will in a minute when I sort out getting round the log on..

OK, back in action I think...

All are ...../chart_0.* > .../chart_9.*

jpg might be your best option, lower resolution than the PDF but smaller file.

For the PDF version>
to: query@saildocs.com
send http://paddyb.pythonanywhere.com/static/chart_0.pdf

JPG
send http://paddyb.pythonanywhere.com/static/chart_0.pdf.jpg

PNG
send http://paddyb.pythonanywhere.com/static/chart_0.pdf.png

small JPG
send http://paddyb.pythonanywhere.com/sta....pdf.small.jpg


Guessing you'll be most interested in the chart_0 which is the latest one.

Wrap up warm now


The code should anyone be interested....

#!/usr/bin/python3.6
from __future__ import print_function
from urllib.request import urlretrieve

from wand.image import Image

from bs4 import BeautifulSoup
import urllib.request as urllib2
import re
from datetime import datetime

html_page = urllib2.urlopen("http://www.dmi.dk/en/hav/groenland-og-arktis/iskort/oestgroenland/")
soup = BeautifulSoup(html_page, 'html.parser')

msg = ''
msg = 'Updated at (utc) ' + str(datetime.now()) + '\n'

for i, link in enumerate(soup.findAll('a', attrs={'href': re.compile("^/uploads/tx_dmidatastore/webservice/W/B")})):
    #print(link.get('href'))
    imageLink = 'http://www.dmi.dk' + link.get('href')

    filename = "mysite/templates/green_ice/chart_" + str(i) + ".pdf"
    print(filename, imageLink)
    urlretrieve(imageLink, filename)
    msg += 'http://www.dmi.dk' + link.get('href') + '\n'

    with Image(filename=filename) as img:
        with img.convert('png') as converted:
            filenamepng = filename + ".png"
            converted.save(filename=filenamepng)
            print(filename)
        with img.convert('jpg') as converted:
            filenamejpg = filename + ".jpg"
            converted.save(filename=filenamejpg)
            print(filename)

    with Image(filename=filename) as imgsmall:
        imgsmall.resize(int(imgsmall.width/1.5), int(imgsmall.height/1.5))
        print(imgsmall.width, imgsmall.size)
        with imgsmall.convert('png') as converted:
            filenamepng = filename + ".small.png"
            converted.save(filename=filenamepng)
            print(filenamepng, imgsmall.size)
        with imgsmall.convert('jpg') as converted:
            filenamejpg = filename + ".small.jpg"
            converted.save(filename=filenamejpg)
            print(filenamejpg, imgsmall.size)


with open("mysite/templates/icelinks.txt", "w") as f:
    f.write(msg)

[Dockhead]

It works, and it's brilliant!

[conachair]

Originally Posted by Dockhead

It works, and it's brilliant!

Excellent . That will remain running until your save return

Seen these ones?
NAEFS Probabilistic Wind Speed Guidance

[Dockhead]

Thanks a million to Conachair for the great ice chart utility.


Our volunteer weather router, TeddyDiver (to whom many many thanks!) was sending us satellite pictures, which were extremely useful, but during the 3 weeks we were in Greenland (or on passage to or from there), we used Conachair's utility to get the Danish ice charts with the egg codes! It was a great help to us; thanks!

[Dockhead]

Originally Posted by conachair

Excellent . That will remain running until your save return

Seen these ones?
NAEFS Probabilistic Wind Speed Guidance

That's worth a separate thread!


I've made one here: NOAA Probabilistic Wind Charts - Cruisers & Sailing Forums