Question

PostGIS Raster write overview

  • 18 August 2021
  • 2 replies
  • 3 views

Badge +4

Hi,

I have some problems to write an overview to a raster on a PostGIS-Database. The workflow runs without a problem, but the original raster is reduced in size. It gets the same resolution from the lowest resampler. What is wrong or where is my logic mistake?

Thanks!

FME_Raster


2 replies

Badge +6

The RasterResampler works by comparing your desired resolution to the original resolution and outputs the resampled resolution, this is probably why you're seeing your raster reduced in size.

Could you outline what you are trying to achieve in this workspace? There may be a better set of raster specific transformers that may work better for you :)

Badge +4

Hello @jennaatsafe​ , thanks for you reply. I try to load 3 rasters to a PostGIS server. The first raster is the original one, the second is reduce in size and the third is reduce more in size than the second one. The Overview should speed up the loading (like a rasterpyramider) . You load the first picture (the original one) and the others are linked as an Overview, so the third picture load, because the zoomlevel is zoom out. When you zoom in, the second raster must load and then the original raster come up at the lowest scale. I try this settings from the PostGIS-Writer:

Raster_EinstellungenThere are no error, but the original raster get the same resolution from the third raster. The Overview Factor is 2 and 4 (like you see in the Workflowpicture above).

What is the mistake I did?

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