I imported my image with three bands (RGB) with 100*100 tiles using raster2pgsql into the DB. Now, I need to export those tiles separately. I used the following code but it produces a table

 select st_aspng(st_reclass(rast,1,'0-100:0-100','8BUI',0)) from myraster.test where rid=1;

So I need some help to improve this code or even revise it to a suitable form.

1 Answer 1


I found the solution to this question:

Using gdalwarp and PG was worked:

gdalwarp -t_srs EPSG:4326 -tr 100 100 -of PNG -r bilinear PG:"host=localhost port=5432 dbname='postgis' user='***' password='***' schema='chp01' table='raster_table' mode='1'" rast_name.png

mode - option is used to know the expected arrangement of the raster table. There are 2 possible values

mode=1 - ONE_RASTER_PER_ROW mode. In this case, a raster table is considered as a bunch of different raster files. This mode is intended for raster tables storing different raster files. It’s the default mode if you don’t provide this field in connection string.

mode=2 - ONE_RASTER_PER_TABLE mode. In this case, a raster table is considered as a unique raster file, even if the table has more than one row. This mode is intended for reading tiled rasters from database.

In my case since I imported the image in different tiles, number 1 can provide suitable result

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