WeatherFax ...

[nohal]

Hi Windows testers...
Attached is a new DLL built from the latest code available. Get the file, get rid of .doc and copy to your plugin folder. OpenCPN 3.1.x needed

Pavel

[LJH]

Originally Posted by nohal

Hi Windows testers...
Attached is a new DLL built from the latest code available. Get the file, get rid of .doc and copy to your plugin folder. OpenCPN 3.1.x needed

Pavel

I just gave this a quick go using two large TIF files. It worked well.
Set top left coordinates then bottom right with and without scrolling the window.
Chart responded normally to mouse inputs and the redraw was normal.

with OpenGL selected

• both transparency sliders worked well.
• when changing scales the fax layer was visible on all scales.

without Open GL selected

• only lower slider worked.
• when changing scales the fax disappeared when the scale was zoomed closer than 1:2,000,000

OpenCPN 3.1.1328
Win 7 (64bit) SP1
NVIDIA 560M

A couple of additional comments

• The first tiff I tried to load was transmitted with North to the left side of the page! Have to remember to check the orientation next time.
• I liked it when I zoomed in and the fax disappeared as it was not providing much info close in. That said is is easy to make it transparent when you don't want it visible.

Excellent work getting this in working order - Thanks

[rgleason]

Downloaded Pavel's, ( Nohal) wxfax_pi.dll put in plugins file in Opencpn3.1.1405
Tested with OpenGl on and off.
Loaded gif, tif, wxfaxes
Loaded two wav file examples from this thread.
All seemed to work with opengl and not.

Did not test zooming or sliders under both opengl and not.
Went back to test that and the wav, tif, gif file that I had set up were no longer available without going back and setting them up. So did not test that.

OpenCPN 3.1.1405
Win 7 (64bit) SP1
NVIDIA 560M
also Intel Integrated Graphics with and without Opengl

====

Would like to suggest interface improvement for coordinate setup

The user interface for setting coords and lat long is improved. Thankyou.
I have some ideas to make it more intuitive I think.

1. Have the weatherfax image or wav open with the coords (0,0) marked with a "0" at the upper left corner, and an "X" at the (500, 800 -for example) corner. I am pretty sure the program can determine the image size or has that available.

2. Then have a note to drag the "0" and "X" markers to nearest Long Lat and then to complete the respective fields. (Drag and release left button to located the "X" or "O"

3. For Coord Set 1 show an "O" identifier.
4. For Coord Set 2 show an "X" identifier.

====
Liked Leaseonlife's
Calibration and re-projecting sat images would be great. And imagine, overlaying a synaptic chart over a sat image.
======
Responses to Sean:

As far as the next revision goes.. I have planned:

-- Direct audio capture with spectrum analyzer (make tuning frequency and bfo really easy)

- GREAT

-- skew correction -

GREAT

-- polar->mercator conversion. What different formats are most common? This is really not that difficult to do it just requires a little math. Should it be selected with a pole position and curvature coefficient (visually adjust until lines are flat) or some other way? -

Would be very nice, but maybe later?

-- warp button to center of selected current fax (if possible for an opencpn plugin to do this, if not.. another patch to opencpn core will be needed)

-Don't know how difficult.
-

- save fax list images between sessions (note the last update saves the coordinate sets but not the image list) -

YES this would be very nice!!

-- More advanced filters for removing noise from an image and at least making the noise transparent not black

- Ok sound good.

still need to find a suitable library for direct audio capture on all platforms.

Then for the next revision (after that) there are mostly questions to be answered:

Is there any need to display multiple fax images at once?

It might be very nice. Also Leaseonlife satillite over synoptic example. Maybe just highlight multiple files similar to windows using control - left button or something?

Would it be useful to align coordinate sets with image sets? By this I mean.. normally you get a bunch of images in a 6-12 hour period and the order and location of each image is pretty much known.

YES -This would be very helpful.

This way you could have a coordinate set defined for each radio frequency and (assuming phasing is detected and there are not skew problems) you could with
one action grab all the weather fax images at once and have them all placed correctly and aligned.

-Sounds very good.

Then pre-defined coordinate sets for each station could be included (people would have to send them in to add them to the main distribution somehow), and the user interaction minimized. -

This sounds great, we would build a library of available and it would be setup for use..

So opening an audio file captured from the radio would be much like opening a grib file, only you would select the radio frequency you used and the time you started receiving from a list.

Software radio.. Does anyone know of a suitable software radio (that can go low enough) for weather fax? It would be great to support this hardware since the cost is low.. so far the ones I have found go down to 22mhz which is still too high.

-- Software Radio, what is the range we need, low and high, I will help look.

[seandepagnier]

Originally Posted by LJH

without Open GL selected only lower slider worked. when changing scales the fax disappeared when the scale was zoomed closer than 1:2,000,000

That is correct. The top slider is only implemented in opengl.. Maybe I should disable it or something otherwise.. it would be very slow to implement without opengl.

Also without opengl it is very slow to render zoomed in very close, so there is a cut off point to avoid stalling the program too much which is why that happened.. Maybe I should render notice explaining this like grib does?

A couple of additional comments<ul><li>The first tiff I tried to load was transmitted with North to the left side of the page! Have to remember to check the orientation next time.
Excellent work getting this in working order - Thanks

Did you need a 90 degree rotation? This should be a very easy feature to add.

Originally Posted by rgleason

Downloaded Pavel's, ( Nohal) wxfax_pi.dll put in plugins file in Opencpn3.1.1405
Tested with OpenGl on and off.
Loaded gif, tif, wxfaxes
Loaded two wav file examples from this thread.
All seemed to work with opengl and not.

Did not test zooming or sliders under both opengl and not.
Went back to test that and the wav, tif, gif file that I had set up were no longer available without going back and setting them up. So did not test that.

====

Would like to suggest interface improvement for coordinate setup

The user interface for setting coords and lat long is improved. Thankyou.
I have some ideas to make it more intuitive I think.

1. Have the weatherfax image or wav open with the coords (0,0) marked with a "0" at the upper left corner, and an "X" at the (500, 800 -for example) corner. I am pretty sure the program can determine the image size or has that available.

2. Then have a note to drag the "0" and "X" markers to nearest Long Lat and then to complete the respective fields. (Drag and release left button to located the "X" or "O"

3. For Coord Set 1 show an "O" identifier.
4. For Coord Set 2 show an "X" identifier.

Do you think dragging is better than clicking? This is sometimes worse on computers that have trouble dragging things.

====
Liked Leaseonlife's
Calibration and re-projecting sat images would be great. And imagine, overlaying a synaptic chart over a sat image.
======
Responses to Sean:

...
It might be very nice. Also Leaseonlife satillite over synoptic example. Maybe just highlight multiple files similar to windows using control - left button or something?

YES -This would be very helpful.

But then how to change transparency individually for each image? Maybe one of the checked list boxes where many can be checked but a single one is selected?

-Sounds very good.

This sounds great, we would build a library of available and it would be setup for use..

This is certainly part of the plan, but I think I will tackle other things first.

-- Software Radio, what is the range we need, low and high, I will help look.

There are devices like the r820t that cost $11 and go as low as 24mhz and may go lower with modification. The same hardware could decode ais receive vhf, fm, and lots of other stuff. For me weatherfax needs to go down to 10mhz or lower to be really useful, so this would possibly require an upconverter.. Should be possible to build one for $10 or less.

[seandepagnier]

Apparently on the $10 sdr, you can bypass the input filter and do the conversion directly using aliasing. This gives the 0-30mhz range needed for weatherfax, but requires soldering the antenna wire to a small pin on the board.

[LJH]

Originally Posted by boat_alexandra

That is correct. The top slider is only implemented in opengl.. Maybe I should disable it or something otherwise.. it would be very slow to implement without opengl.

Also without opengl it is very slow to render zoomed in very close, so there is a cut off point to avoid stalling the program too much which is why that happened.. Maybe I should render notice explaining this like grib does?
Did you need a 90 degree rotation? This should be a very easy feature to add.

Under stood, then it worked as advertised!
A 90 degree rotation would be great as Boston sends the surface analysis sideways!

Originally Posted by boat_alexandra

Do you think dragging is better than clicking? This is sometimes worse on computers that have trouble dragging things.

I prefer to drag if I am using a mouse, but not if I am using the touchpad. In a moving boat, I use the touchpad. I would think clicking is a better way to do it on a laptop.

[rgleason]

1. Have the weatherfax image or wav open with the coords (0,0) marked with a "0" at the upper left corner, and an "X" at the (500, 800 -for example) corner. I am pretty sure the program can determine the image size or has that available.

2. Then have a note to drag the "0" and "X" markers to nearest Long Lat and then to complete the respective fields. (Drag and release left button to located the "X" or "O"

3. For Coord Set 1 show an "O" identifier.
4. For Coord Set 2 show an "X" identifier.

Do you think dragging is better than clicking? This is sometimes worse on computers that have trouble dragging things.

I think it would be good to have different identifiers show up over the set coord set latlong fax for each of Coord 1 and Coord 2.
I don't know how hard that is to do. The middle of "O" would be the first coord and the middle of the "X" would be the second.

Maybe its an option to be able to drag it? OR you can also enter the values under Set Coord.

I understand it needs to accommodate different hardware, but I think this will make it more intuitive... connecting the Coords values to the "O" and the "x" overlaid on the fax.

Don't want to make it worse for other computers, still keep the direct entry fields.

[rgleason]

How about this alternative for Set Coords:
1. Keep radio buttons.
2. Have a bullseye at the cursor when selecting coord points.
3. When point is selected with a click have a lighter bullseye or other symbol dot land at the point selected.
4. When a point has to be changed, first select SetCoord 1 or SetCoord 2 radio button for point which needs changing. Then move cursor into the fax field and cursor turns to bullseye. User clicks coord spot & leaves another symbol showing location.
5. Then user has to enter the lat longs.
6. Maybe some of the prompts would go away so it is more streamlined?
This way it is still just clicks and not drags.

[seandepagnier]

almost...

[LeaseOnLife]

Originally Posted by boat_alexandra

almost...

way cool!

[seandepagnier]

the trouble is, the polar projection the distance between the curved latitude lines is expanding.. so farther from the pole they get wider. I assumed at first they were constant. I tried with a quadradic fit and it helped a lot to get closer but it isnt actually correct. Maybe I need to use trig and fit it to a sphere.. I'm not actually sure what equation they used. Then the mercator part turns out to be a pain but I solved it.. it has to use arcsin((exp(2*y)-1) / (exp(2*y)+1)) and .5 * log((1+sin(t)) / (1-sin(t)))) to make it work. I might be able to correct for more than just polar projections. Then I project onto a huge image to get the best end result (for the screenshot) and found there is a limit on gl texture size.. so I guess that needs to get fixed. Anyway getting closer...

[seandepagnier]

success! now I need to clean up the mess I made, and figure out a user interface for this. Essentially I need 3 datapoints to convert from polar to mercator. The pixel coordinate of the pole and equator (can be outside the image) and the coordinate of the vertical meridian. Then a 4th coefficient is needed if the parallels are not equally spaced.

So in all, this requires the user to click the map on 2 (or 3) places along the vertical meridian and enter the latitudes at each location.

[rgleason]

Well done. Congratulations.

[Littlechay]

Thanks for all who have been developing this! I have been following with interest for some time.

I downloaded the windows plugin this morning to test.

I would like to use the charts available here which I also receive at sea via HF. The current analysis is in polar stereographic projection which I understand is currently not supported but all the forecast maps are in some kind of rectangular projection; the question is which? and is it supported? I have been unable to successfully calibrate one yet.

One glitch I notice in the calibration dialogue is that when I click on the first calibration point on the map nothing happens except that the selected radio button moves to point 2, a second click (on the first point) enters coordinate data into the second point etc.. so it requires three clicks to enter 2 coordinates and they are out of logical sequence.

on my fairly powerful laptop DELL XPS15 i7 things slow to crawl as soon as I hit 'OK' on the new fax dialogue.

[cagney]

boat_alexandra

B...dy good!

All this fits nicely into another related scenario.
Calibrate chart pictures directly, bypassing the bsb kap files.
It also opens up the possibility to support other projections, as well as, perhaps, better support for Tmercs (in high latitudes) and Polyconicals.



Just a test. Right now it's not possible to enter decimal degrees, and larger pictures quickly slows down the process to near a standstill.

Thomas