We at Blue Sky Analytics are building several large environmental raster datasets. By large, we mean really really large ~ 50TB. We began by hosting these raster files on an S3, from where they were clipped and coloured on the frontend. This gave us more control on the ability to stylize raster tiles the way we wanted them. But this client side rendering meant sluggish user experience on the browser and no one likes waiting for things to load, right?

We thought why not stylize and colour the rasters on the backend itself? This would help speed up the loading times of the rasters on the UI - no more heavy lifting for your device. The only challenge with this was that it was not possible to iterate with various colour schemes like it was possible to do on the frontend. We had to take a dummy raster into QGIS, stylize it using a colour palette and then see how the render looks like. And if you did not like what you saw, you had to repeat the process till you found something you did. This process of testing on QGIS also slowed down deployment of the rasters. We wanted the ability to test out colour palettes quickly.

Meet Raster Playground - an open source tool we at BSA have developed that lets you input a set of raster tiles, shapefiles (optional) and a color palette to visualize how a colourized raster looks like. This is our second open source tool after the AQ Calculator. We hope to build more useful and potent tools for the mapping and climate communities.

A glimpse of Raster Playground in action

A glimpse of Raster Playground in action

Raster Playground uses OpenLayers (an open-source JS library for displaying map data in web browsers as slippy maps) and ReactJS (an open-source JS library for building user interfaces). We load black and white (data) XYZ tiles to the browser and colour it using rainbowvis.js (an open-source JS library for colour data visualisation) on raster source's render time operations. We then clip it with a shapefile to tidy it up.

How it works.

How it works.

The Raster Playground also serves an additional purpose for us. It will also give prospective employees and interns an idea of the work we do at Blue Sky. We do a lot of map-heavy work and a familiarity/comfort with mapping tools and libraries is necessary.

Help us make this tool better. Start by contributing to this project. There are quite a few issues and forks made already. Why not go ahead and fix one of its issues? Or suggest new ones?

If you are someone who wants to work with us, there is no better way to catch our attention than contribute to this project.

You can check out our Workable profile and see if something fits to your liking.


We've made our first hire using Raster Playground! Meet Hanumanth, a recent graduate from Bengaluru, who has now joined us as a Frontend Developer at Blue Sky. He was selected among several hundred applicants across India for his contributions to Raster Playground. Just look at his pull requests!

We are still on the lookout for one Frontend Developer and one Web Developer. So what are you waiting for? Send in that pull request!

We are very keen on diversifying our team, so women candidates are highly encouraged to apply. And also, please, please__, apply with your portfolios or links to your work!