GDAL-RASTER-OVERVIEW-REFRESH(1) GDAL GDAL-RASTER-OVERVIEW-REFRESH(1) NAME gdal-raster-overview-refresh - Refresh overviews Added in version 3.12. SYNOPSIS Usage: gdal raster overview refresh [OPTIONS] Refresh overviews. Positional arguments: -i, --dataset, --input Dataset (to be updated in-place, unless --external) [required] Common Options: -h, --help Display help message and exit --json-usage Display usage as JSON document and exit --config = Configuration option [may be repeated] -q, --quiet Quiet mode (no progress bar or warning message) [not available in pipelines] Options: --external Refresh external overviews -r, --resampling Resampling method. RESAMPLING=nearest|average|cubic|cubicspline|lanczos|bilinear|gauss|average_magphase|rms|mode --levels Levels / decimation factors [may be repeated] --bbox Bounding box to refresh Mutually exclusive with --like, --use-source-timestamp --like Use extent of dataset(s) [may be repeated] Mutually exclusive with --bbox, --use-source-timestamp --use-source-timestamp Use timestamp of VRT or GTI sources as refresh criterion Mutually exclusive with --bbox, --like Advanced Options: --oo, --open-option = Open options [may be repeated] DESCRIPTION gdal raster overview refresh can be used to refresh existing overviews of a dataset. By default all overviews are refreshed, but it is also possible to restrict the refreshed overviews by level and/or extent. PROGRAM-SPECIFIC OPTIONS --bbox ,,,ymax> This option performs a partial refresh of existing overviews, in the region of interest specified by georeferenced coordinates, in CRS units. 'x' is longitude values for geographic CRS and easting for projected CRS. 'y' is latitude values for geographic CRS and northing for projected CRS. --dataset Dataset name, to be updated in-place by default (unless --external is specified). Required. --external Refresh external .ovr overviews. --levels A list of overview levels to build. Each overview level must be an integer value greater or equal to 2. If not specified all existing overviews are refreshed. --like [,]... This option performs a partial refresh of existing overviews, in the region of interest specified by one or several filenames (names separated by comma). Note that the filenames are only used to determine the regions of interest to refresh. The reference source pixels are the one of the main dataset. By default all existing overview levels will be refreshed, unless explicit levels are specified. See Example 2. -r, --resampling {nearest|average|cubic|cubicspline|lanczos|bilinear|gauss|average_magphase|rms|mode} Select a resampling algorithm. The default is nearest, which is generally not appropriate if sub-pixel accuracy is desired. When refreshing existing TIFF overviews, the previously used method, as noted in the RESAMPLING metadata item of the overview, will be used if -r is not specified. The available methods are: nearest applies a nearest neighbour (simple sampling) resampler. average computes the average of all non-NODATA contributing pixels. This is a weighted average taking into account properly the weight of source pixels not contributing fully to the target pixel. bilinear applies a bilinear convolution kernel. cubic applies a cubic convolution kernel. cubicspline applies a B-Spline convolution kernel. lanczos applies a Lanczos windowed sinc convolution kernel. gauss applies a Gaussian kernel before computing the overview, which can lead to better results than simple averaging in e.g case of sharp edges with high contrast or noisy patterns. The advised level values should be 2, 4, 8, ... so that a 3x3 resampling Gaussian kernel is selected. average_magphase averages complex data in mag/phase space. rms computes the root mean squared / quadratic mean of all non-NODATA contributing pixels mode selects the value which appears most often of all the sampled points. --use-source-timestamp This option performs a partial refresh of existing overviews of a VRT -- GDAL Virtual Format or GTI -- GDAL Raster Tile Index file with an external overview. It checks the modification timestamp of all the sources of the VRT and regenerate the overview for areas corresponding to sources whose timestamp is more recent than the external overview of the VRT. By default all existing overview levels will be refreshed, unless explicit levels are specified. See Example 1. STANDARD OPTIONS --oo, --open-option = Dataset open option (format specific). May be repeated. RETURN STATUS CODE The program returns status code 0 in case of success, and non-zero in case of error (non-blocking errors emitted as warnings are considered as a successful execution). EXAMPLES Example 1: Refresh external overviews of a VRT file using timestamp of source files This is needed when for sources have been modified after the .vrt.ovr generation: gdal raster mosaic tile1.tif tile2.tif my.vrt # create VRT gdal raster overview add --external -r cubic my.vrt # initial overview generation touch tile1.tif # simulate update of one of the source tiles gdal raster overview refresh --external -r cubic \ --use-source-timestamp my.vrt # refresh overviews Example 2: Refresh (internal) overviews of a TIFF file gdal raster mosaic tile1.tif tile2.tif mosaic.tif # create mosaic gdal raster overview add -r cubic mosaic.tif # initial overview generation gdalwarp tile1_modif.tif mosaic.tif # update mosaic gdal raster overview refresh --like=tile1.tif my.tif # refresh overviews AUTHOR Even Rouault COPYRIGHT 1998-2026 August 18, 2026 GDAL-RASTER-OVERVIEW-REFRESH(1)