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Index › Programming Questions & Help › Syntax Questions › Looking for advices (heat-map creation) !
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Looking for advices (heat-map creation) ! (Read 1731 times)
thbar
Looking for advices (heat-map creation) !
Mar 6th, 2008, 10:21am  
Hello,

I'm new to Processing and I like it so far ! I'm seeking some advice here.

I have a series of "weighted plots" (x,y,weight) from which I'd like to create a heat-map with processing, on top of a map (similar to http://www.heatmapapi.com or http://www.labsmedia.com/clickheat/index.html).

Here is what I think I'll be doing:
- create a transparent image (8 bits shades of gray)
- for each plot, blend (multiply) a alpha-gradient disc on the transparent image
- once all plots are blended, colorize the image (translate the shades of gray to a palette)
- add a background map taken from google maps.

As I'm very new to Processing, I'd be interested in other users opinion: is there an easier or more elegant way to create something like heat maps ?

any hint welcome!

best regards,

Thibaut Barrère / LoGeek
--
http://blog.logeek.fr - learning content for developers
http://evolvingworker.com - tools for a better day
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toxi
Re: Looking for advices (heat-map creation) !
Reply #1 - Mar 6th, 2008, 7:09pm  
Maps like this are done like this: for every pixel in the image calculate the average distance to all sample points of your dataset. Then use this distance as a lookup index in a gradient map to get the colour for this pixel.

Here's an example made with an ancient version of Processing. It's a totally different context, but utilizes the exact same principle:

http://toxi.co.uk/p5/blobsInterlace/

Hope that helps!
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