Jukka After reading your message assuring me that -dstalpha does work for others, and since what I was doing seemed so basic, I decided to re-boot my computer and try again (I have recently been using some large graphics files). Lo and behold I am now getting the expected result, transparency outside the original image area. :-) Thanks for your response.
Jack On Mon, 2020-02-10 at 02:26 -0700, jratike80 wrote: > Hi, > > It does really work for others. I just verified with GDAL 3.1.0dev and 2.4.2 > on Windows. Could you repeat the test carefully with the bare minimum > > gdalwarp -dstalpha without_alpha.tif with_alpha.tif > > If it does not work please arrange a reproducible test case for us by > telling how to get exactly same GDAL version as you have, and point same > source tiff file as input. > > -Jukka Rahkonen- > > > Jack Glendening wrote > > For gdalwarp (GDAL 2.3.1), using -dstalpha (hoping to get transparent > > pixels outside the original image area) ala > > > > gdalwarp -dstalpha -srcnodata 0 -t_srs EPSG:4326 in.tif out.tif > > > > for an input geotiff RGB image (created by gdal_translate) I get an RGB > > output image, not an RGBA as I expected. From googling, it appears > > -dstalpha works for others. This seems so simple, cannot understand > > what could be going wrong. > > > > Jack > > > > > > _______________________________________________ > > gdal-dev mailing list > > > [email protected] > > > https://lists.osgeo.org/mailman/listinfo/gdal-dev > > > > > > -- > Sent from: http://osgeo-org.1560.x6.nabble.com/GDAL-Dev-f3742093.html > _______________________________________________ > gdal-dev mailing list > [email protected] > https://lists.osgeo.org/mailman/listinfo/gdal-dev -- John W. (Jack) Glendening 831-484-6929 25953 Deer Run Lane Salinas, CA 93908 _______________________________________________ gdal-dev mailing list [email protected] https://lists.osgeo.org/mailman/listinfo/gdal-dev
