Importing large raster datasets

Importing raster datasets in the range of 10 GB or less can usually be done with the default Map Import settings. The general documentation on importing maps can be found here.

However, if the dataset you are importing is significantly larger - 20 GB or more - the settings become more important to get a good result without using too much processing time and file size. This article will go more in-depth on the different parameters and how they affect the import process and result.

Image Quality

Image quality in this context refers to how similar the output result is to the input data. This can be objectively measured as Structural Similarity (SSIM). We have run a benchmark comparing different compression methods and formats here.

Relevant Map Import parameters:

Resampling

This is the method to use when creating downsampled versions of the main dataset (also called pyramids or overviews). The default resampling method is average. The following table shows a benchmark comparing the different methods. Each row shows the percentage difference in execution time from average

Method	Difference vs. baseline
average	0%
nearest	-9%
bilinear	36%
cubic	46%
cubicspline	43%
lanczos	57%
gauss	28%

Full article here: Comparing resampling methods in massivegeopackage