That seems to be something wrong in the algorithm or configuration, as it
is not "ignoring" the pixels with nodata value.
Could you dump the output of "gdalinfo" of the original file, and the exact
command line you are using with gdalwarp ?
.___ ._ ..._ .. . ._. .___ .. __ . _. . __.. ... ._
Hi All,
Thanks for your comments. I replaced the no data value (which previously was
-200) with zero and then it all seemed to work!
Best wishes,
Ainslie
> On 1 Jul 2022, at 20:39, Andrew C Aitchison wrote:
>
> On Fri, 1 Jul 2022, Ainslie Johnstone wrote:
>
>> Hi there,
>>
>> I am trying
On Fri, 1 Jul 2022, Ainslie Johnstone wrote:
Hi there,
I am trying to downsample a high-resolution file of gridded
population estimates (1km res over the whole world). I want the
downsampled version to give the total population in the new
lower-resolution grid. However, whenever I downsample us
Hi there,
I am trying to downsample a high-resolution file of gridded population
estimates (1km res over the whole world). I want the downsampled version to
give the total population in the new lower-resolution grid. However, whenever I
downsample using gdalwarp -r sum, I don’t seem to be gett
I've got a slightly older version of the data you're using (OS 10k B&W,
but with 2 bits per pixel rather than four), and I've used a two-stage
process to achieve what you want.
First, I used gdal_translate to expand the image to 8-bit greyscale:
gdal_translate -co "TFW=YES" -co "TILED=YES" -expan
Thanks for the replies so far, but I'm obviously missing a trick as it
doesnt seem to be working.
The gdalinfo on my TIF looks like this.
E:\rasters>gdalinfo tq00ne.tif
Driver: GTiff/GeoTIFF
Files: tq00ne.tif
tq00ne.tfw
Size is 7874, 7874
Coordinate System is `'
Origin = (505000.00
Rob,
You can try the -dstalpha option in gdalwarp to create an alpha band. (
http://www.gdal.org/gdalwarp.html)
On Fri, Jun 18, 2010 at 7:22 PM, Rob wrote:
> Hi Guys
>
> I'm reprojecting some rasters from OSGB (EPSG:27700) to WGS84 (EPSG:4326)
> and am running into a problem.
>
> The rasters ar
Hi Guys
I'm reprojecting some rasters from OSGB (EPSG:27700) to WGS84 (EPSG:4326)
and am running into a problem.
The rasters are reprojecting nicely, but I am left with black pixels around
the image where the reprojected image doesnt fit squarely within the
rectangular dimensions of the file.
I
