Scene from above

I’ve been severely neglecting my blog on account of focusing on writing up my PhD project as well as being sick (don’t underestimate the pain of getting your tonsils out as an adult!).

I wanted to write up a decent post for my 100th entry, but have subsequently realised it’s lead to me posting nothing for the last couple of months! I have a plan for a good entry coming up, though will need to find the time to put it together.

In the meantime, I picked up that Alistair Graham (geoger), who gave a talk at the conference I ran this year, and Andrew Cutts, who I have never met, though I remember worked through the straightforward openCV GUI demo from his website which I thought was great, have started a podcast, scene from above.

Science communication is tricky at the best of times, so I’m excited they’re giving this style of delivery a crack. The demo episode discusses Sentinel 5p and the larger scope of the sentinel project, remap’s webapp and cloud computing more generally, and the launch of a Moroccan satellite.

I think the discussion of the webapp was my favorite part. I appreciated Alistair’s humility in admitting that maybe he was approaching interaction with data from a point of view that was somewhat outdated, as he seems (as am I!) skeptical of the benefits of a sleek interface. Admittedly the app isn’t designed with me or others in the RS community in mind, but I can’t see it being used much in it’s current iteration.

Thinking of my ornithologist friends currently in PhDs/postdocs who would be the target audience for an app like this, they would almost definitely look at it for an hour or two with interest, and never think to use it again. Having consistently tried to get them interested in RS and accurate mapping, the tools need to be unbelievably simple to get people to consider using them seeing as so much of other scientists time is dedicated to learning specialist knowledge and general computing skills. It’s one of the many challenges of interdisciplinary work in science!

I’m looking forward to the next episode of the podcast, and hope a forum opens up for discussion online as I think I’d have something to contribute, and would love to hear other people’s opinions on these ideas!

Keep an eye out for a longer update soon 🙂

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Django greyscales

Access the application here.

I’ve been learning lots about the django web framework recently as I was hoping to take some of the ideas developed in my PhD and make them into public applications that people can apply to their research. One example of something which could be easily distributed as a web application is the code which serves to generate greyscale image blocks from RGB colour images, a theme touched on in my poster at EGU 2016.

Moving from a suggested improvement (as per the poster) using a complicated non-linear transformation to actually applying it to the general SfM workflow is no mean feat. For this contribution I’ve decided to utilise django along with the methods I use (all written in python, the base language of the framework) to make a minimum working example on a public web server (heroku) which takes an RGB image as a user input and returns the same image with a number of greyscaling algorithms (many discussed in Verhoeven, 2015) as an output. These processed files could then be redownloaded and used in a bundle adjustment to test differences of each greyscale image set. While not set up to do bulk processing, the functionality can easily be extended.

web_out

Landing page of the application, not a lot to look at I’ll admit 😉

To make things more intelligible, I’ve uploaded the application to github so people can see it’s inner workings, and potentially clean up any mistakes which might be present within the code. Many of the base methods were collated by Verhoeven in a Matlab script, which I spent some time translating to the equivalent python code. These methods are seen in the support script im_proc.py.

Many of these aim to maximize the objective information within one channel, and are quite similar in design so it can be quite a difficult game of spot the difference. Also, the scale can often get inverted, which shouldn’t really matter to photogrammetric algorithms processes, but does give an interesting effect. Lastly, the second PC gives some really interesting results, and I’ve spent lots of time poring over them. I’ve certainly learned a lot about PCA over the course of the last few years.

web_out.png

Sample result set from the application

You can access the web version here. All photos are resized so they’re <1,000 pixels in the longest dimension, though this can easily be modified, and the results are served up in a grid as per the screengrab. Photos are deleted after upload. There’s pretty much no styling applied, but it’s functional at least! If it crashes I blame the server.

The result is a cheap and cheerful web application which will hopefully introduce people to the visual differences present within greyscaling algorithms if they are investigating image pre-processing. I’ll be looking to make more simple web applications to support current research I’m working on in the near future, as I think public engagement is a key feature which has been lacking from my PhD thus far.

I’ll include a few more examples below for the curious.

 

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MP map

Just a quick entry detailing an interactive map showing MPs’ constituencies and party membership created at the request of a friend. It uses leaflet.js and geojson to draw the map, meaning it’s standalone html code which can be easily moved and modified.

mp_map.png

It’s based largely on the chloropleth example included in the leaflet documentation and was pretty interesting to make!

You can see it at my website here.

Website update

Having spent a little bit of time learning about various web apps and making different models to test their capabilities, I’ve gotten around to slapping together something of a better repository for the research I’m undertaking. The aim will be to host compressed versions of all models that form part of anything I present or discuss in the academic community for reference of whoever may need it. It’s still a work in progress, but the consolidated design can be seen here. Any feedback would be appreciated! I plan to populate it with other things mentioned on this blog, as well as other ideas I have for thematic maps and photoscans!