I am trying to segment a raster image to get a vector output. I am using OTB 6.6.1 in QGIS 3.4. In the segmentation window, I selected the input raster which is a 3 band (true colour) sentinel 2 image and chose the meanshift under segmentation algorithm and chose an output file name with .shp as output. I left all the other options to default. I am getting the output as a blank rectangle. I am getting a perfectly segmented image if I choose watershed instead of meanshift in segmentation algorithm . Any suggestions ?
Did you try to run the meanshift algorithm from command line, too? Very often the QGIS-connection does not work properly. I never use it. If you are scared by the command line, then use the Monteverdi tool instead. Another reason is that the Sentinel image is too large? I suggest trying a subset instead of using the whole image.
HTH