Fix regression caused by string param type change in 1e422b43e3a2ad418d2d6080ad8f80192726c98d
Merge pull request #4 from pez4brian/master

Fix regression caused by string param type change in 1e422b43e3a2ad418d2...
Add 'VI' calculation and color component selection
Cairo uses premultiplied alpha, but not frei0r; need to convert.
Merge branch 'master' of github.com:ddennedy/frei0r
Add legend to NDVI filter.
Merge pull request #5 from pez4brian/master

NDVI component selection and legend