I have some tiffs that I'd like to plot interactively in python using folium (or any other package, but I don't know of any). My problem is, that I have many na-values in the raster. At the moment I read in the raster with rasterio, read the data into a 2d-numpy-array, and then I write it back out as .png. Finally I use folium with:

rasterlayer = folium.FeatureGroup(name = "raster")
                        bounds=[[bottom, left], [top, right]],

But I get all the NA-Values printed in some colour. And I didn't find any solution to that problem. I had a look here:


but also did not really help. I also did set all NA-values in the "numpy"-array to 0, but this also was not the solution. The NA-Values always got plotted. Is there some, relatively easy way, to omit the plotting of na values. And more general: What is a good way of plotting raster with folium? It seems that in R it's so easy with packages like mapview or tmap and in python it feels way more complicated...

1 Answer 1


I couldn't find a solution that worked apart from building my own colormap. This function will make the lowest 100 values in the scale transparent

    def cmap(cm, scale=9999):
        from matplotlib.colors import ListedColormap
        ncm = np.zeros((scale, 4))

        pcm = ListedColormap(ncm)

        ncm = np.vstack((pcm(np.linspace(0, 1, 100)), cm(np.linspace(0, 1, 2000)))

        return ListedColormap(ncm)

Worked off this document https://matplotlib.org/3.1.0/tutorials/colors/colormap-manipulation.html

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