geotiff tiff - What's the best way to display a huge aerial image using GeoServer

I have an aerial image - almost 1.5 GB , GeoTIFF - and I have been trying to add it as a layer in GeoServer...

Adding the layer went successful, but the performance was very bad.

I tried to cache the layer using GeoWebCache, and the performance is still bad.

Any tips?

Answer

You need to tile the image and add overviews so that the whole image is never read into memory at the same time. GeoServer provides an image pyramid datastore for this purpose.

I wrote these notes describing how I set this up on my machine. The key step is to use GDAL to build the pyramid using the following command:

mkdir bmpyramid
gdal_retile.py -v -r bilinear -levels 8 -ps 2048 2048 -co \
"TILED=YES" -targetDir bmpyramid \

bluemarble.tif

Where-

• -v: verbose output, allows the user to see each file creation scroll by, thus knowing progress is being made (a big pyramid construction can take hours)


• -r bilinear: use bilinear interpolation when building the lower resolution levels. This is key to get good image quality without asking GeoServer to perform expensive interpolations in memory


• -levels 8: the number of levels in the pyramid


• -ps 2048 2048: each tile in the pyramid will be a 2048x2048 GeoTIFF


• -co “TILED=YES”: each GeoTIFF tile in the pyramid will be inner tiled


• (Not used here) -co “COMPRESS=JPEG”: each GeoTIFF tile in the pyramid will be JPEG compressed (trades small size for higher performance, try out it without this parameter too)



• -targetDir bmpyramid: build the pyramid in the bmpyramid directory. The target directory must exist and be empty


• bmreduced.tiff: the source file

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Utility notes for gdal_retile.py.