Abstract: A depth-first walk of a tree structure is performed to populate nodes of the tree structure with corresponding merged tiles of a merged data pyramid to be generated during the walk from source tiles. At a first visit of a target node, a source tile from a first source data layer corresponding to the target is fetched and stored in memory as a first source-derived tile corresponding to the target. At a last visit of the target, a resampling on source-derived tiles from a second source data layer stored in memory corresponding to children nodes of the target node is performed to generate and store in memory a second source-derived tile corresponding to the target node. Also, at the last visit of the target, at least the first and second source-derived tiles are merged to generate a merged tile of the merged data pyramid corresponding to the target.

Abstract: A depth-first walk of a tree structure is performed to populate nodes of the tree structure with corresponding merged tiles of a merged data pyramid to be generated during the walk from source tiles. At a first visit of a target node, a source tile from a first source data layer corresponding to the target is fetched and stored in memory as a first source-derived tile corresponding to the target. At a last visit of the target, a resampling on source-derived tiles from a second source data layer stored in memory corresponding to children nodes of the target node is performed to generate and store in memory a second source-derived tile corresponding to the target node. Also, at the last visit of the target, at least the first and second source-derived tiles are merged to generate a merged tile of the merged data pyramid corresponding to the target.