Closes #778

With Claude (bedrock)

• TiTiler tile layer support band math expressions
• As does the IdentifierTool
• User can, if configured to permit them to, modify the expression within the given layer's LayersTool settings.
• The Admin can configure the default band math expression for COG raster layers
• The Admin can also configure whether users will be able to customize the band math expression in the LayersTool raster layer settings or not.
• The COG settings for tile layers in the configure page has moved the Core Tab to a new COG tab.

Expression Syntax

Expressions seem to be mainly a standard math expression ()+-/* where bX (or BX) (where X is the band number) are the variables for bands. I'm not sure if you'll need to worry about this part but, when constructing an RGB image from an expression, it would use ; to denote each output band (so red_expression;green_expression;blue_expression). To represent a different asset within the STAC item, use a _ between the asset name and band: assetname_bX

Example: asset1_b1 + asset2_b1 / assest3_b1 + 50

Images