search

opengeospatial / geopackage-tiled-gridded-coverage

A GeoPackage extension for tiled, gridded coverage data
Apache License 2.0
5 stars 8 forks source link

Tile Edges to support 3D Display #37

Closed mousebird closed 7 years ago

mousebird commented 8 years ago

This is more in the nature of a question.

Does the standard support an extra row and column of data values at the edge of each tile?

Essentially this is a one row/column overlap of data values between neighboring tiles. It's very useful for loading tiles independently and displaying them in 3D. Without this each individual tile is dependent on its neighbors to generate the right geometry for visual display or interpolation.

bosborn commented 7 years ago

I don't believe this would be supported by the current spec without an additional column stating the overlapping pixel size.

My unreleased implementation had to increase the query size and maintain border information while consecutively processing rows. A bicubic interpolation requires additional overlapping pixels (2 in most cases but 3 on edge cases based upon rounding direction).

mousebird commented 7 years ago

I figured, but it's good to know for sure.

Thanks.