Heatmaps

[Midgardsormr]

If you can render the paths and overlay them meaningfully, then the heatmap approach still works, but I'm not sure how easy it will be to accomplish in typical graphics software. The process I am about to detail will work in any linear environment where you can use floating point colors and perform meaningful math on them.

Render each of your paths as a white line on black. Then put all of the lines in a layer stack with a simple add blend mode. This will push your color way above white, so now you need to divide the result by the number of layers in your stack. That will normalize the image to put your brightest colors back to no brighter than white. Once you have that, you can use the technique of your choice to make a gradient out of it, adjust the gamma for a pleasing look, or whatever.

Now, about that bit in the first paragraph: A linear, floating point environment is difficult to set up in the Gimp or Photoshop. I'm sure it can be done, but if I were performing this job, I'd probably use Blackmagic Fusion, which was conveniently just released for free. Fusion is a node-based image compositor used to make feature film visual effects. As such, it's ridiculously powerful, and a little difficult to wrap your brain around at first. If you'd like to go for it, though, I can set up a template for you and walk you through how to use it to achieve your goal. You can download the software here: https://www.blackmagicdesign.com/products/fusion

And yes, it really is free.

[nameh]

If you can ... Fusion is a node-based image compositor used to make feature film visual effects. As such, it's ridiculously powerful, and a little difficult to wrap your brain around at first. If you'd like to go for it, though, I can set up a template for you and walk you through how to use it to achieve your goal. You can download the software here: https://www.blackmagicdesign.com/products/fusion

And yes, it really is free.

Man this is awesome piece of software! Unfortunately for my hobby map it would be a huge time-killer. Before I say "thank you, but no", let me summarize the knowledge I gathered so far.

A) I was thinking about a heat map of my rides. Road intersections have GPS coordinates
B) However not being able to set up (in fact I don't know how easy/difficult would it be and what kind of knowledge one should have) GeoServer and GeoTools, I took the approach which was suggested - to use some graphics software instead. I chose Inkscape which I used for other map.
C) I put my tracks on a paper map and divided them in sections (each being restricted by road intersection)
D) Each section I numbered and each number I summed so basically I received the number of times I passed the section in real life
E) These numbers I used to Normalize, to be able to calculate heat map colour (based on this formula: A_minimalist_heatmap_function)
F) Until now everything was fine and made on paper

1) I started drawing it in Inkscape so I made 1st layer which was a copy of a Google map road map
2) the uppermost layer would be left for captions
3) second layer would be used to draw lines = road sections as in D)
3a) first problem occurred: If I run through the same road section once or multiple times it does not need to be divided at each road intersection (for time saving reason). However if in future I used part of the road, I would need to divide it at the intersection where I stepped in. How would I number the sections so I knew where in the map it would be? (some of the roads do not have a number in real life so a naming method would have to be made. For those roads that have numbers, it would be rather difficult t use real life system because they may be more than 60 miles in length). The only option which I was able to figure out, was a number followed by a letter. Still the road section may be split (e.g. 1, divided in 1a and 1b. 1b can still be divided in 1b and 1c, however when I split 1b, I need to name 1b as 1ba and 1bb so that 1c can remain). The new numbers must be maintained and updated in a table for colour normalization (point E)
2b) There is one option how to resolve the issue in 2a) If I painted each track as a separate layer. But there would be problem with the fact that I would need to redraw each track individually but I don't know how it would work with colour merging so that the colours would make "heat map" effect.

I probably wrote more than you are keen to read, but I did it even for me to summarize my work so far, so I could come back and knew what I did and where the dead ends were.

Now comes the time to ask all of you and Midgardsormr especially. Have I put myself in a dead-end direction or am I going just through longer routes than necessary and would there be better tools or processes to use?

Thank you all. And thank you Midgardsormr for your will to give me a hand with Fusion.

BTW: sorry for typos and grammar mistakes as English is not my mother tongue