Multi-resolution raster data access method, apparatus, electronic device, and computer storage medium

An apparatus comprising:

• one or more processors;
• memory;
• a determination module stored in the memory and executable by the one or more processors to execute a corresponding window query input to determine a target pixel resolution corresponding to a query window according to a raster data access request;
• a judging module stored in the memory and executable by the one or more processors to calculate a sampling level according to the target pixel resolution and a stored pixel resolution of a raster object, and determine whether the sampling level is greater than a threshold;
• a first access module stored in the memory and executable by the one or more processors to access raster data corresponding to the query window according to a column-level index if the sampling level is greater than the threshold, the column-level index being an index generated by down-sampling according to raster data of the raster object in a column;
• and
• a column index generation module stored in the memory and executable by the one or more processors to perform a splicing operation on pixel matrices of a root node of a row-level index of the raster object, perform a down-sampling operation on an obtained splicing result matrix, and generate the column-level index according to a down-sampling result, before executing the corresponding window query input to determine the target pixel resolution corresponding to the query window according to the raster data access request.

One or more non-transitory computer readable media storing executable instructions that, when executed by one or more processors, cause the one or more processors to perform acts comprising:

• executing a corresponding window query input to determine a target pixel resolution corresponding to a query window according to a raster data access request;
• calculating a sampling level according to the target pixel resolution and a stored pixel resolution of a raster object, and determining whether the sampling level is greater than a threshold;
• and
• accessing raster data corresponding to the query window according to a column-level index if the sampling level is greater than the threshold, the column-level index being an index generated by down-sampling according to raster data of the raster object in a column, wherein before executing the corresponding window query input to determine the target pixel resolution corresponding to the query window according to the raster data access request, the acts further comprise performing a splicing operation on pixel matrices of a root node of a row-level index of the raster object, performing a down-sampling operation on an obtained splicing result matrix, and generating the column-level index according to a down-sampling result.