Hello there! All the files mentioned in this message can be found here: https://www.swisstransfer.com/d/0722395d-64a4-48fc-8ac9-534e1444fc43
In my company we are currently developing a software in which a user can input different types of raster images (GTiff/JPG/PNG/etc.). They can have a different band type, source cs, etc. All these different types need to be converted to a specific type (rgba, WGS84, GeoTiff encapsulated in a VRT). We already have an automated process, which does this quite well. This process uses gdal commands. This VRT will then further be processed in another application, which needs exactly this format. But there is a problem with a specific input, which has the format JPG/rgb/etrs89. Ssrs info is in this case provided by a .prj-file (ssrs.prj) by the user. If I look at the end result in QGis (qgis_result.jpg), there is a transparent line where the two raster sets meet. I found out that there is NO transparent line when using one of the following resampling methods: max, min, med, mode, q1, q3, sum. When using one of the following resampling methods, there IS a transparent line: average, bilinear, cubicspline, cubic, lanczos, near, rms. The resampling method can be chosen by the user. The following commands are used (gdal v3.4.3.): #1. Converting to GeoTiff: gdal_translate -r cubic -co COMPRESS=LZW -co PREDICTOR=2 left.jpg left.tif gdal_translate -r cubic -co COMPRESS=LZW -co PREDICTOR=2 right.jpg right.tif #2. Warping to WGS84, adding an alpha band. gdalwarp -r cubic -s_srs ssrs.prj -t_srs EPSG:4326 -dstalpha left.tif left.vrt gdalwarp -r cubic -s_srs ssrs.prj -t_srs EPSG:4326 -dstalpha right.tif right.vrt #3. Bundling the raster sets. gdalbuildvrt -r cubic all.vrt *.vrt (For visualization only) #4. Creating a tif out of the vrt. gdal_translate -r cubic -co COMPRESS=LZW -co PREDICTOR=2 all.vrt all.tif It seems to me that the alpha channel has a nodata value at the overlapping areas. But I'm really not sure what happens here. I really could use some help. Why is there a transparent line between the raster tiles? Thank you and kind regards, Sebastian _______________________________________________ gdal-dev mailing list [email protected] https://lists.osgeo.org/mailman/listinfo/gdal-dev
