Extracting information from an aerial UV photo

Also on Youtube. Cesar Harada (http://opensailing.net) and Adam Griffiths (http://www.wcu.edu) for Public Laboratory.

>> Question : How can you extract the % of wetland from an UV aerial picture using photoshop? 

_ Instructions : 

1. isolate the part that you are interested in using the menu/ image/ adjustment/ replace color. There you want to have a quite fuzzy selection and darken the desired part. 

2. after isolating the part you are interested in -black area- apply menu/ image/ adjustment/ threshold

3. use magic wand /untick "contiguous" pixel to select all the black pixels available. Open menu/ window/ histogram/ expanded view. Here you will see how many black pixels are selected.

Now you know how many black pixels there is on this image - corresponding the area of wetland from the original UV picture. You can convert the number of pixels into a % (proportions of wetland) or in surface area for quantifying. 

It is possible to optimize this workflow by creating a script or recording the chain of actions.

Filed under  //  DIY   Grassrootsmapping   Histogram   Image   Mapping   Photoshop   Public Laboratory   Research   Teaching   Tutorial  
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big red thing?

I think, isolated from its context this image is very strange and funny :

Filed under  //  Alabama   Balloon   Blur   Funny   Grassrootsmapping   Joke   Mapping   Photo  
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Mapping River Dog Mouth, Mobile Alabama



Yesterday we went aerial mapping a landscape that is just about to change radically : restoration of the oyster reef in Mobile AlabamaDog river mouth - known as Helen Wood Park beach. In two hours from now (2011 January 22 6AM), hundreds of volunteers will come to install a massive oyster reef here. From 8AM today "Volunteers will be deploying approximately 23,000 bags of oyster shells to create new reefs and habitat at the mouth of Dog River" - see them in action here .

 



Aerial mapping Prof. Dawn McKinney & Prof. Leo Denton of the University of Mobile South Alabama. Thanks to Shannon Dosemagen for organizing the trip. 



These are the different reefs and bags of oyster they are installing. 5 non-profit organizations are working together to accomplish this massive landscaping project. 


We took about 5000 aerial pictures that I turned into 3 very large resolution maps to make one huge map (at the top of the post):



Download these full resolution maps to your computer as .zip file (27mb). If you want to learn how to make one of these map, check this post.


This time, in addition of aerial photography, I also took ground samples (~250x microscopy), sand, sediment, organic material taken at regular interval. The idea is : if we are able to say what is on the ground - sometimes we may find oil spilled still - we can qualify and quantify what we see on the aerial pictures. We will come back in a few weeks to map again and see the effects of installing an artificial oyster reef here : "before and after" :) 
sample -1, 20110121 Anne Wood Park, Mobile, Alabamasample 1, 20110121 Anne Wood Park, Mobile, Alabamasample 2, 20110121 Helen Wood Park, Mobile, Alabamasample 3, 20110121 Helen Wood Park, Mobile, Alabamasample 3b, 20110121 Helen Wood Park, Mobile, Alabamasample 3b, 20110121 Anne Wood Park, Mobile, Alabamasample 4, 20110121 Helen Wood Park, Mobile, Alabamasample 5, 20110121 Helen Wood Park, Mobile, Alabamasample 6, 20110121 Helen Wood Park, Mobile, Alabamasample 8, 20110121 Helen Wood Park, Mobile, Alabamasample 10, 20110121 Helen Wood Park, Mobile, Alabamasample 11, 20110121 Helen Wood Park, Mobile, Alabamasample 12, 20110121 Helen Wood Park, Mobile, Alabamasample 14, 20110121 Helen Wood Park, Mobile, Alabamasample 15, 20110121 Helen Wood Park, Mobile, Alabama

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date : 20110121@15:41, low-tide. 
Location : 30.57562, -88.07847 
Mapping for Grassroots Mapping & LA Bucket Brigade
Photos : Prof. Leo Denton and Prof. Dawn McKinney 
Stitching : Cesar Harada 
Left at 10:45 - return 20:30 
Milleage : start 761963 - end 764803

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Re-Posted on the Grassroots Mapping blog page : http://grassrootsmapping.org/2011/01/mapping-river-dog-mouth-mobile-alabama/

Filed under  //  Aerial   Alabama   Grassrootsmapping   Helium   LA Bucket Brigade   LABB   Mapping   Mobile   Nature   Oyster   Reef   Reserve   Restoration   River  
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How I feel right now

Sometimes, the colors of an image can describe best how I feel.

Filed under  //  Mapping   NOLA   Photography   Road Movie   Road Trip  
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Bay Jimmy, post-oil spill observation

Second post but first large map using the techniques of Grassrootsmapping.org for LA Bucket Brigade – thanks guys for putting this wonderful DIY technology together. So! In the late morning 22nd of July 2010, Hunter Daniel and myself went to map out of Port Sulphur, on these funky boats :

LABB troops, Seen from the ground, Bay Jimmy LA, After the Oil Spill, 20100722

With 2 boats we took this route (see google map) :

20100722 Grassroot-mapping, Bay Jimmy

I traced this route with my mobile phone Google Nexus One and the fantabulous Open GPS tracker for Android – 4 stars rating!
This is what we could see from the boat, kinda boring :

Seen from the ground, Bay Jimmy LA, After the Oil Spill, 20100722

Soon after I launched a balloon and Hunter a kite out there, kinda exciting :

Seen from the Balloon, Seen from the ground, Bay Jimmy LA, After the Oil Spill, 20100722

we captured nice pictures, here 6 details :

Bay Jimmy, Detail 01, 20100722 Bay Jimmy, Detail 02, 20100722 Bay Jimmy, Detail 03, 20100722 Bay Jimmy, Detail 04, 20100722 Bay Jimmy, Detail 05, 20100722 Bay Jimmy, Detail 06, 20100722

These 6 pictures were made using 270 stills… that was a 12 hours work on photoshop sincehugin (an open-source photo mosaic software) didnt do the trick – yet :/ Still working on it to automate the process and spend more time sipping mango juice :)
In addition to what we had a bad GPS trace – my bad, I mean, it is good but I did’nt know where we started taking pictures on that route… Also the GPS time-stamp and the camera time-stamp did not match… So, here is the trick I found:

  • 1. stitch approximately consecutive images with multiple layers on photoshop, when your shape takes shape you may guess where you are on the map. If you only have pictures of water, you can make a great water map … USELESS! BOOO! When your balloon/kite is up  there, make sure it is flying over what you want to see, for us, the coast line – land and water. Wind is crucial, and because of the sun you want to avoid taking pictures when the sun is too high (reflection of the sky in the water).
  • 2. produce a very high resolution map of the area. I didn’t want to do it all manually and I wanted to figure out a hack that would work on every platform (OSX, Windows, Linux), so here we go :
    - find your point of interest on any map system, write down the coordinates of the top left hand corner of the tile you want to produce.
    - go to http://pallit.lhi.is/bigice/bigpic.html , from here enter your Lat and Long (me : 29.468400, -89.911300), the zoom, number of tiles etc… hit “submit”. It will produce a huge map with a static URL. In my case the URL that produced the map (everything is in the URL PHP request) you see here :
    http://pallit.lhi.is/bigice/supergooger.php?lat=29.468400&lon=-89.911300&zoom=18&x_tiles=40&y_tiles=40
  • – now you have this huge picture, you need to capture it from your browser, download theScreenGrab! add-on for firefox only – but working on all platforms (download Firefox NOW if you don’t have it, you…!). Now, grab that huge picture with the tiny ScreenGrab! button at the bottom right corner of your browser, save as png or jpg.
  • 3. Now, it is much easier to map with a support map! just keep adding layers on photoshop of all the pictures you took, adjusting, stretching, so it matches roughly google maps – you will often find that land shape changes, trees, rivers, buildings etc… that’s very exciting, this is why we are mapping : everything changes !
  • Ok, so now we have this huge empty map :

    Bay Jimmy, empty old google map, 20100722

    That’s another 6 hours work adjusting 700 pics layer by layer on photoshop ; hey, 270 images in 12 hours VS 700 images in 6 hours => see, it is much faster with a support map! We got that :

    Bay Jimmy LA, After the Oil Spill, 20100722 _Desaturated

    Don’t forget to put a scale and cardinal orientation + legal mentions.
    So, under your eyes that’s a 17000 x 17000 pixel map, made of 970 pictures taken at 1000ft altitude, depicting about 5 linear km of damaged coastline. Combining the 6 details views and the general map we could observe that the south side was much more exposed to the spill (more dark brown brrrrr). Using this map we could also establish that on the exposed side, even the inland waterways are strongly affected by the spill : we can use these maps to quantify the surface affected by the oil spill, and the mass of crude attached to the surface coastline. Now even cooler, you can see these maps on google earth, download the KMZ file here (dont worry it is a tiny file – all the content is online). FLY !

    Apart from mapping this catastrophe – which is very useful for scientific study and for lawsuits against BP- why am I personally learning aerial photography? Well, because I am currently designing an oil collecting robot called “protei“.

    Protei.org

    Protei is a sailing semi-autonomous robot with a long oil absorbing tail. Surface oil drifts downwind, so Protei sails upwind, taking and taking, intercepting oil sheens. Imagine many many of these cheap machines out there in the ocean collecting oil :)

    Protei.org

    After some research …
    Protei technical drawing

    I built a steampunk test machine that is pretty promising with a flexible hull front-steering :

    Protei.org

    We are also testing at sea the behavior of a long tail, and same, going pretty well …

    Long test for Protei.org

    See these little balloons on the surface of the water? And this is when aerial photography comes handy : to evaluate the efficiency and behavior of Protei, seeing everything from above helps a lot, I can see the trajectory, the movement of the tail, the interaction with oil.  Also having a highly visible “flying flag” in the sky is amazing to optimize safety and long range communication (flying antenna)… Exciting no? And the challenge is here, millions of liters of crude oil gushing in the Gulf of Mexico, in the Niger Delta, in Latin America, the middle east, in Asia… Protei_Oil_Spill has a busy future!

    Of course, just like grassroots mapping, Protei is developed open-source and collaboratively, so I hope that sometimes soon, Protei will come back to land with a lot of amazing pictures for LA Bucket Brigade and its amazing oil  spill map, GrassrootMapping,Cartagen and Open_Sailing! I received most electronic parts for the next prototype of Protei_Oil_Spill this morning (YAY!), I am building in New Orleans, so if you are around, or if you want to help the project remotely, do get in touch – cesar@protei.org – thanks!

    Filed under  //  Balloon   Barataria   Bay   Boat   DIY   Grassrootsmapping   Hacking   Jimmy   LA Bucket Brigade   LABB   Louisiana   Mapping   NOLA   New Orleans   Observation   Oil   Oil Spill   Open_Sailing   Protei   Robot   Science   Sky   TEDxOilSpill  
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    Grassroots mapping

    A couple of days ago, we went with the folks of LA Bucket Brigade (again!) to do some grassroots mapping (aerial photography actually) in the Bay Jimmy & Wilkinson Bayou (29.45193, -89.89812), and it was superb ~ and dystopic :/


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    Seen from up there is so different from what you see from the water :


    We went in those super cool (noisy though) boats :
     
    Boat seen from the balloon (!!!) :
     
    This is how it works :
     
    So we do the same but with a helium Balloon flying at ~1000ft, with a camera attached to it, looking down, taking a picture automatically every 5 seconds or so : 

    I took a chance to try to enhance the "photography cabin" with Sue Stoessel, Bennie Gregory and Hunter Daniel (in a previous mapping trip though): 
     



    You see, it is just a bottle of soda and some duct tape, you can DIY it!
     
    Now you may wonder why we take these pictures :
    - for science study and evaluation of the impact of the oil spill on the coast and the marsh lands.
    - for legal purposes, so we have evidences of the impact of the oil spill at the court of justice ;) 

    I'm in love with this technique Gonzo Earth and Grassrootsmapping keep on improving, also because I really need it to assess the efficiency of the oil spill collecting robot I am working on : protei.org. Here we were testing to see how well we can sail the robot upwind with a long tail : 

     
    that's the robot I am prototyping this week : 
     
    If you want to help on the making of the protei robot, or do some aerial photography of the oil spill, get involved at LA Bucket Brigade, contact Shannon Dosemagen <shannon@labucketbrigade.org>, or Hunter Daniel <hunterdaniel@gmail.com> 901-550-7667 directly by phone to arrange a trip in the sun :)

    Filed under  //  Aerial   Balloon   Barataria   Bay   Grassrootsmapping   Helium   Jimmy   LA Bucket Brigade   LABB   Louisiana   Mapping   NOLA   New Orleans   Oil Spill   Photography   Stitching   TEDxBoston   TEDxOilSpill   Tilling  
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