Petascope_Support rasql ready colorPaletteTable from external metadata color palette file

[Bang Pham Huu]

One can add a colorPaletteTable as JSON object in an external file and used it in generalRecipe as global metadata, e.g:

"global": {
              "Title": "'Drought code'"
         	  },
             "colorPaletteTable": "PATH/color_palette_table_rasql_READY.cpt"
          }

And this file should contain 256 RGB color values such as ​https://pastebin.com/iFcqkLGv.

Then, in petascope when encoding as png or tiff, this colorPalette is added implicitly and return the colorful result.