colormap questions

[gagecarto]

I am working through a solution for a custom colormap. My datasets is scaled 0-58. I rescale in my titiler requests and then apply a viridis color ramp. This works great.

http://myurl/WebMercatorQuad/9/105/186@1x?
url=myCogUrl
&bidx=1
&nodata=999
&rescale=0,58
&colormap_name=viridis

Questions...
Can I easily reverse/flip the rio-tiler color ramp?

If wanted to apply my own color ramp made up of 3 colors ['#f0ff00', '#ffb000', '#ff0000'], can I do that directly in my tile request urls?

[dvd3v]

Yes this is possible if you add a custom Colormap dependency. There is an example in the documentation: https://devseed.com/titiler/examples/code/tiler_with_custom_colormap/

[gagecarto]

Thanks... How about reversing an existing color ramp?

[vincentsarago]

@gagecarto

Can I easily reverse/flip the rio-tiler color ramp?

most of the Colormap are provided by matplotlib and have both regular and reverse. you can try using viridis_r