Steve, first, if your data is non lossy you need to nearblack -nb 0 -near 15
however your DOQQ's dont have a collar so there is no reason to nearblack gdalwarp -dstalpha will crate an alpha band to mask out the collar after gdalwarp rotates the image. no nead to nearblack the output of gdal warp. when using gdal_translate to create a tiff with a mask band, and you warped file has a alpha band, gdal_translate -b 1 -b 2 -b 3 -mask 4 this will crate a mask band from the alpha band brian On Sat, 2017-02-11 at 18:18 -0500, Stephen Woodbridge wrote: > Hi All, > > I need your wisdom. I'm downloading NAIP DOQQs in GTiff format and I > have a processing chain something like the following: > > gdalwarp -t_srs EPSG:4326 -dstalpha -r "bilinear -multi -co TILED=YES > -dstnodata '0 0 0' srctiff tmpfile > > nearblack -nb 15 -q tmpfile > > gdal_translate -co TILED=YES -co JPEG_QUALITY=90 -co COMPRESS=JPEG -co > PHOTOMETRIC=YCBCR -b 1 -b 2 -b 3 -mask auto --config > GDAL_TIFF_INTERNAL_MASK YES tmpfile, target > > nearblack -nb 5 -q target > > gdaladdo -clean -r bilinear target 2 4 8 16 32 64 128 512 > > And create a tileindex for mapserver of all the tiffs > > If I skip the gdal_translate (ie: JPEG compression) and the 2nd > nearblack, the doqq tiles are perfect with no nearblack edges between > the doqq tiles. But when a JPEG compress them, I get edges between the > doqqs like this: > > http://imaptools.com:8080/dl/doqq-issue.jpg > > I've never used the JPEG in tiff compression and I'm very impressed by > the amount of size reduction there and how good the image remains, but I > have not been able to figure out the magic trick to clearing the edge > artifacts. > > Any help would be appreciated. > > Thanks, > -Steve > > --- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus > > _______________________________________________ > gdal-dev mailing list > gdal-dev@lists.osgeo.org > https://lists.osgeo.org/mailman/listinfo/gdal-dev _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org https://lists.osgeo.org/mailman/listinfo/gdal-dev
