WhatsApp Images

One thing I’ve noticed since sharing images across a range of formats/websites, is that image compression algorithms on various platforms vary noticeably. This is most evident, from my experience, with WhatsApp, where images tend to be resized without even an anti-aliasing filter. The results are images with huge amounts of speckle in them when they are not resized before uploading.

Obviously the target market for WhatsApp and its user base isn’t people using high end cameras to share their images on the application, but it still seems like a couple of functions could fix a lot of the visual problems that I see, which would save me having to do it locally.

It seems astounding to me that such a big company wouldn’t put more time into sensible image compression/resizing, or perhaps they have and I am catching exceptions. The blocky artifacts I’ve written about being associated with the algorithm on this blog before are evident. Even with the third example included, where the image was resized to 20% of it’s sized before compression applied produces a much better result qualitatively, even with the smaller pixel count upon redownload of the latter.

Whilst whatever algorithm they are using is likely directed towards smartphone camera users it still seems like an oversight by the developers. Hopefully WordPress doesn’t apply a similar type of compression when I post this now!

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Reflecting on Wavelength

Two years ago I agreed to join the committee of a professional body known as the Remote Sensing and Photogrammetry Society (RSPSoc), a professional body whose remit is to promote and educate its members and the public on advancements in Remote Sensing Science. When I signed up to join as the Wavelength representative, I admittedly knew very little about not only how this society operated, but societies in general, and what their function was in the greater scope of progress of Science. I took on the role knowing I’d have to learn fast, and, after a two year lead period, host a conference focusing on Remote Sensing and Photogrammetry, which would serve to bring early career researchers from both academia and industry together to discuss the latest advancements in RSP Science.

The first Wavelength conference I attended way back in 2015 was at Newcastle, a few months after my first conference experience at the 2014 GRSG meeting in London, just two months after starting my project.

The difference was apparent, with the GRSG attracting the old guard from all over the world to contribute to the conference. I distinctly remember Nigel Press, a veteran Remote Sensor and founder of NPA satellite mapping, turning around to the crowd during a Q and A session pleading with people to start taking risks funding/supporting hyperspectral satellite missions, as their contributions to geological research was so apparent. I didn’t mention it in my write up from that conference, but it really stuck with me as, at least for that minute, it all seemed so human. But apart from that, it was all quite formal and difficult to tell how I, as a novice, could really play a part.

With Wavelength, however, this humanity is what it’s all about! When everyone’s a novice, you can afford to be a bit more gung-ho with your opinions. As someone who tries to always ask, or at least dream up, a question during Q and A portions of talks, I loved it so much. Rich bluesky discussions have kept me motivated around the inevitable slower portions of writing and finicky data processing of my project, and Wavelength had them in buckets! The fact that I got so much out of it was part of my reason for volunteering to host it, as I felt like it would be a way for me to contribute back to the community, and get more involved in RSPSoc.

After an extremely enjoyable and well-run conference at MSSL during the spring of 2016, it was up to me to deliver a conference in Kingston in March 2017, while coordinating the final run in to my PhD project. While things could definitely have been done better, and I should have maybe been a bit more ruthless about advertising the conference to a wider audience, I have to say I think it ran quite smoothly, and the delegates got a lot out of it, as did I! I’ll include a summary of each day below, and my favourite parts throughout the three day agenda, including a longer description of one delegate presentation.

Monday 13th March

Delegates arrived at Kingston train station at around 11.30 am. I had enlisted the help of my colleague Paddy to go and meet the delegates, as I had to run up the poster boards to the conference room. After lunch and a quick roll call, things kicked off with 6 talks spanning image processing and Remote Sensing of vegetation.

Andrew Cunliffe, eventual winner of best speaker, showed some captivating UAV footage of Qikiqtaruk, a site where arctic ecology is being furtively researched to try to gain insight into differences between observations at different scales, both the changing ecological and geomorphological landscapes. I was interested in his hesitance in saying what he was doing for UAVs was not ‘ground truthing’ of satellite images, but more ‘evaluation’ thereof, as ground truth was never really acquired (outside of GCPs for a few of the 3D models). You can check out his profile on google scholar, which lists some pretty interesting research!

Monday wrapped up with a meal at a local Thai food restaurant, the Cocoanut, a staple with the Kingston Research folk!

Tuesday 14th March

After a tour of Kingston’s town centre in the morning, we returned to the conference venue to listen to Alastair Graham, of geoger fame, give an insightful and extremely helpful talk about career options for Remote Sensing scientists. I felt really lucky to have had the opportunity to host him – truth be told it was a bit of a fluke we crossed paths at all! He had been retweeting some of the tweets from the @sentinel_bot twitter account I had made, which caused me to look at his twitter and subsequently his website. Realising he was organising an RS meeting in Oxford the month before Wavelength (Rasters Revealed), I jumped at the chance to get him onboard, and I’m glad I did! I won’t go into his use of sli.do, but only mention that it’s worth looking into.

On Tuesday, James Brennan’s talk about the next generation of MODIS burnt area products brought me back to my Masters’ days at UCL, and my time spent with the JRCTIP products. James’ talk was focused on the binary nature of classification, and how he was looking into using a DCT to model behaviours of fires, something like a fuzzy land classification. It was really engaging and I enjoyed his super-relaxed style of presenting.

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Delegates eye up some posters

Tom Huntley of Geoxphere also came in to give us a talk on recent advancements with their spinout hardware company, which provides high quality cameras for mapping purposes: the XCam series. Wavelength tries to bridge the gap between industry and acamemia, and both Tom and Alastair’s talk brought in the industry element I was hoping for.

After a nice meal at Strada Kingston, we hit the bowling alley before wrapping up day 2.

Wednesday 15th March

Wednesday’s session opened with delegates talking about mainly data processing. Ed Williamson, from the Centre for Environmental Data Analysis (CEDA) gave a very interesting introduction into the supercomputing facilities they provide (JASMIN), as well as services offered to clients choosing to avail of these services. They host the entire Sentinel catalogue, which is such an outrageous amount of data, and so it was interesting to be given a whirlwind tour of how this is even possible, practically speaking.

We also had the pleasure of listening to José Gómez-Dans from NCEO talk to us about integrating multiple data sources into a consistent estimation of land surface parameters using advanced data assimilation techniques. I had done my Masters’ thesis with Jóse, and (somewhat) fondly remember trying to interpret charts where the error bars couldn’t even be plotted in any reasonable way on them. This is the reality of EO though, uncertainty is part and parcel of it!

The poster session featured a wide range of topics, I even put up my one from EGU last year, and participants were extremely interested in drought mapping in Uganda, as well as numerous uses for InSAR data presented. Congrats to Christine Bischoff for winning the best poster award with her investigations of ground deformation in London.

Proceedings wrapped up with deciding on the next incoming Wavlength host (congrats to Luigi Parente, of Loughborough Uni) and a lovely lunch in the sun.

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Sunny group shot

Summary

Wavelength was really fun and interesting to organise, and I hope it’s a tradition we can keep going as a society. I’ve made the conference booklet publicly available here. For those of you who might be reading this blog and aren’t members I suggest you join, the benefits are evident.

For now, for me, it’s EGU and beyond – I’m also aiming to attend the annual RSPSoc conference in Imperial in September with latest developments from my fieldwork data!

Sony a7

I was fortunate enough to track down a Sony a7 within my price range last weekend. I’ve written about it in a number of forms on this blog (UAV cameras, revisited, What camera for a UAV?), and have been trying to hunt one down for the last few months.

It arrived this afternoon, and I’ve had a little play with it just to try and get a feel for it’s operation. Coming from a comparatively stone age Canon 500d, the controls feel slick and the electronic viewfinder also feels very different, but good different. It came with the 28 – 70mm kit lens, which is good news as I think it might have been a pain to track one down separate from the body.

One huge upside I’ve already identified is how easily the photos are to upload via Wi-Fi to my computer. I didn’t think it’d matter much to me, but I can see it being quite useful in general, saves from scrambling for card readers and such.

The only downside I’ve identified so far is the punishingly short battery life. The electronic viewfinder is beautiful, and the real time leveling information is amazing, but it drains the battery like nobody’s business. I’ve already ordered a backup battery, and should look forward to taking more photos in less difficult conditions!

I thought I’d include a few sample images here, including one I took of a building site a few minutes from where I live. I really should have brought down a tripod, but the fact that it came out as clear as it did is remarkable to me.

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A building site near my house

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A different angle, lots of light from street

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My first (and probably last) ever selfie, for a special occasion

The geobusiness show

Last week, ontop of attending the peer review workshop which was the subject of my last post, I was lucky enough to attend the geo business show, a trade fair detailing the latest technologies associated with geomatics and visual environment technologies. It’s become a pretty big event, and I’m happy that I could recognize many familiar faces and companies who were presenting the latest products. I attended about 5 talks during the day, ranging from inspiring to drab, as is often the case in trade fairs error isn’t always the main focus. Nonetheless I’ll detail some of what caught my eye, and stuff I’ll potentially delve into in the future.

Smart planes

A slick presentation from a Swedish company mainly detailing a competition in which they participated which saw several surveying firms trying to get recover the most accurate fit for ground checkpoints from an open pit mine. They used Agisoft Photoscan with which I am very familiar, a Ricoh GR3 with all the settings detailed and a fixed wing platform. Their achieved accuracies given the area being surveyed were phenomenal, and while the sample size was low it was very impressive to see!

English Heritage

English heritage gave a presentation on how they were applying new photogrammetric techniques to monitor assets using a mixture of close range photogrammetry and UAVs. They reckoned that photogrammetric surveys could produce models up to LOD ~ 2.75 in about a third the time as would have taken by traditional means. Considering all the equipment they use is a decent DSLR for close range stuff and a pocket camera for aerial photography it shows just how advanced SfM has become in the last few years.

Ecometrica/Carbomap

A joint presentation by two startups looking to promote ethical management of natural resources. Ecometrica have developed a very nice web GIS for producing reports and statistics on queried areas, their demo involved presentation of Saatchi’s map for the Amazon. Considering very recent reports suggesting deforestation in the Amazon is accelerating contrary to recent investigations, it makes the platform more important than ever. While Saatchi’s map does have its inaccuracies, I was happy to spy a healthy uncertainty in the above-ground biomass estimates, as opposed to many other presentations where uncertainties are often not discussed at length.

Carbomap spoke of a TerraSar-X product which they were using to advise forestry councils on timber recover after storm events. Biomass from RADAR is a concept which will come to fruition in the BIOMASS mission, but does have its detractors. The presentation was great, and made use of a handy web GIS to display results in a handy browser based app.

Tomtom

Tomtom, the car navigation system manufacturer presented on how they query all the data they collect to make useful insights into motorists behaviour. They have over 12 trillion data points which they can data mine to see how traffic flow is changing over time, and with such a big dataset I can imagine city planners would be very interested in this sort of stuff. Some questionable jargon was used (Referring to their model as a ‘fusion engine’), but an interesting talk nonetheless!

Pixalytics

A Plymouth based company which use satellite data to advice on bespoke solutions to seemingly big problems. The presentation detailed a range of products, including mixed algorithm images which were actually pretty cool. Later I visited their stand and they had made prints of some of the images which would be great to hang on your wall, might have to look into having a few made up myself! It was nice to see some satellite remote sensing as I’ve been doing smaller scale stuff recently, will be keeping up with their movements as satellite start-ups are all the rage in the US and seem to have a lot of support in the UK at the minute.

In all it was an interesting experience and I look forward to next years event!