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background changes colour

Jul 16, 2014, 04:12
Post: #1
background changes colour
I’d like to know what I am doing wrong in preparing these animations: http://weathercharts.wordpress.com/2014/...m-reports/

When so much as one dot appears on a chart the colour changes for that chart. The first occurrence is with the report for the 4th but it occurs on every chart that has a wind or storm reported.
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Jul 16, 2014, 08:50
Post: #2
RE: background changes colour
As ofnuts said the animation does not look like it passed through Gimp. Are you using an on-line tool to produce these? Who is automattic_inc?

[Image: DibNgGy.jpg]

You can get a result using Gimp, probably many ways, but as a gif animation, change the mode to indexed. The original has 230-something colours but I think you can get away with maybe 16 in indexed mode.

Then it is a matter of editing the colormap, and only 4 colours required a change.
Here is a before/after comparison composite showing the changes.

[Image: UiaMNbP.jpg]

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Jul 16, 2014, 11:49 (This post was last modified: Jul 16, 2014 12:15 by Weatherlawyer.)
Post: #3
RE: background changes colour
The images are from the NWS storm reports:
http://www.spc.noaa.gov/climo/reports/140203_rpts.html (one without any reports.)
http://www.spc.noaa.gov/climo/reports/140204_rpts.html (one with.)

The latter is the first one that turns blue in the animation. It shows three reports of wind damage in Missiissippi. Not a lot of data to choke on.

I am using updated Mageia, a KDE version of Linux. The method I used was/is to save the images which come over as something like:
file:///###NWS Reports 2014/2 February 2014/140206_rpts.gif.png.
This bit:
140206_rpts.gif.png.
comes with "Save image as" from the website.

I save them in a file 1 month long ie, 30 or 31 charts apiece. Highlight and right click to convert them with > Actions > Convert to -and choose Gif.
I can then delete the highlighted files and change the names of the new ones from:
##2014/140206_rpts.gif.gif to ##2014/140206_rpts.gif

All very time consuming (any help on that would be gratefully recieved.)
Then I open Gimp and open the file "As Layers" (select all and open.) Export (change the file name to suit and make sure it is a .gif extension) click export again and the animation diologue opens. I set the menu options in animation to:
As animation
Loop forever
2000 milliseconds
One frame per layer (replace) (I am not sure what choices I have with that but it sounds the safets to go with.)
Use delay on all frames
Use disposal entered above for all frames
Export

Its there I have to hit export twice. The Gif comment box (I don't tick) has the comment default of Created with GIMP. I don't really know what I am doing and am pretty sure I have the settings overloaded somehow. No idea how. Most weather charts are no more than three or four colours. These are the least colourful of the charts I collect.

Some of them turn out horrible. But since even the really bad ones still manage to show the data I am interested in, I am willing to accept it. The less work I need to do on them the better I like it.

Thanks for the prompt responses and in advance for any further help.

Mike.

2nd edit:
That ".gif.png" thing is an American website problem peculiar to US government agencies. Linux recognises they are .png images but I think they have been converted from .gif by the Adobe back-ends that seems to be de rigueur with US agencies these days. (I am just guessing but try saving the volcano archive in Linux from the Smithsonian. Dreadful! Absolutely dreadful.)
If I save them with Microsoft Windows they come across as .gif images and only break down when I try to work on them in Linux.
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Jul 16, 2014, 12:13
Post: #4
RE: background changes colour
Using PClinuxOS KDE here and for a browser SRware Iron (same as Chrome).

A right click and and a save image as screenshot http://i.imgur.com/e4WyHSL.jpg gets quite a decent image, as a gif, without an overlay, but I notice the image size is different 582x408 than your animation 520x365. That animation does look a bit 'jaggy'

Quote:...The less work I need to do on them the better I like it...

That is the crux of the matter, you do not want to have to change colours by whatever method. Try a different browser (KDE will have konqueror in there somewhere) and different method(s) of capture.

FWIW the tweaked gif attached. exported in Gimp to an animation then again to optimise it.


Attached File(s) Thumbnail(s)
   

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Jul 16, 2014, 12:33 (This post was last modified: Jul 16, 2014 12:46 by rich2005.)
Post: #5
RE: background changes colour
A better way of getting those daily images. It looks like that is a fairly simple web site and the images are numbered sequentially.

You should have wget ( or curl) installed, comes with most linux distros, if not it will be in your Magia repo.

fire up a terminal and use the command

Code:
wget  http://www.spc.noaa.gov/climo/reports/140204_rpts.gif

This is the same as the web page url with the html suffix replaced by gif

Here are 3 days captured in a couple of seconds. http://i.imgur.com/7kVAKKf.jpg

edit: I assume that is US date convention Feb - 2 ( -3 -4) 2014

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Jul 16, 2014, 14:50
Post: #6
RE: background changes colour
(Jul 16, 2014 12:13)rich2005 Wrote:  Using PClinuxOS KDE here and for a browser SRware Iron (same as Chrome).

A right click and and a save image as screenshot http://i.imgur.com/e4WyHSL.jpg gets quite a decent image, as a gif, without an overlay, but I notice the image size is different 582x408 than your animation 520x365. That animation does look a bit 'jaggy'

Try a different browser (KDE will have konqueror in there somewhere) and different method(s) of capture.

FWIW the tweaked gif attached. exported in Gimp to an animation then again to optimise it.

I'm using Firefox as I have had trouble collecting the charts in Konqueror. I'll give both a try now though. IIRC I pulled the image to a larger size the Word Press account only gives a small image initially but it opens to a larger size if you click on it.

The possible derecho on the 20th and 21st should have had any number of tornadoes in but they don't show up as red dots in your animation. None the less your idea trumps mine easily. All you did was export it twice?
I think I did that with January for some reason.

I will have to have a look at it but tornadoes are thin on the ground in January.
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Jul 16, 2014, 15:08 (This post was last modified: Jul 16, 2014 15:11 by Weatherlawyer.)
Post: #7
RE: background changes colour
(Jul 16, 2014 12:47)ofnuts Wrote:  Why convert the PNG to GIFs before opening them in GIMP?
If you load all the PNGs in Gimp, you can export the "stack" as an animation with consistent colors across the frames.

A fully automated process something can be cooked around ImageMagick: http://www.imagemagick.org/Usage/anim_basics/
(imagemagick is in your repository).
It is simple to retrieve all the files directly using wget or curl, a short script (10-20 lines) can retrieve all the files and create the animation.

I am amazed. All the more so when you consider the efforts I used to go to.
I had a mixture of stuff saved from NWS and the MetO as was in 2009 and wanted to show what the North Atlantic looked like the day before a tornado spell, so I was put to great pains collating the different file types one after the other.

Mistakenly (as it turns out) I converted them all to gifs; renumbering them (odd numbers for the Atlantic charts and even numbers for the Tornado charts.) But since I had no idea how to make an animation it worked fine.

But now I have to convert them to png to get a decent animation of all 730 charts?
OK.
If that works it will be my first YouTube presentation.
Eyes and fingers crossed.

I'm going to try each of these code tricks and become a nextpert (a next to expert).
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Jul 17, 2014, 03:14 (This post was last modified: Jul 17, 2014 03:22 by Weatherlawyer.)
Post: #8
RE: background changes colour
My problem is that that site is one of the few that stores archived data. I work with forecasts anyway. Those sites that DO store archived charts store them as compiled actual data called analaysis charts.

What I have to have are the forecasts as I am using the errors to cross over into other earth sciences. (Sorry about the long winded explanation but I don't know what is helpful and what you don't need to know.) Anyway I have a few years of stuff composed of various file types. What is the best image to work with?
Changing them from one to another is a piece of cake with Linux.

(Jul 16, 2014 15:15)ofnuts Wrote:  You are not lazy enough. If it's repetitive and boring, it can be automated.

You don't have to convert them back... you just need to redownload them, using wget makes it a snap.

Kicking myself now. I knew I was being an ass. I feel like I just got out of prison. I hate being tied down collecting them one at a time.

Now I have these insights I can start learning about GIMP. I obviously have to start with the beginners guide and just think of the last 20 years as wasted and start again. Once I get over that loss I will be fine.

Thanks once again for all the help. Wish I could buy a bottle of goback.
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Jul 19, 2014, 00:26
Post: #9
RE: background changes colour
(Jul 17, 2014 07:52)ofnuts Wrote:  Gimp isn't really involved here. It's mostly shell scripting.

But yes, this is the major sin of these very graphic User Interfaces, making whole generations think that there is no solution other than endless clicking, because you cannot evolve your clicking into something that can be automated. By contrast individual console commands can some day be chained together in a script file, then some loop/text logic added...

Thanks once again for the help and advice.

That NWS site was a seriously easy one compared to some of the other charts I get. I wonder why every website has a totally different set up. There has to be an ideal presentation, how come they are so disparate?

Anyway I have messed around with a few file extensions and find the best one to convert them to is .jpg. Here is an example, maybe I should have left the previous wonky one in place for comparison but I am made up with these:
https://weathercharts.files.wordpress.co...pc_pac.gif

Now I am going to have to learn shell scripting. Any suggestions?
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