<div dir="ltr">Hey John,<div><br></div><div>That's a lot of information to process :)</div><div>So your conclusion would be that gdal2tiles does not handle TIF "Byte" files properly?</div><div><br></div><div>Would you be able to submit some samples of working TIF + VRT and non-working ones so that I might have a look in the future if it's a bug?</div></div><div class="gmail_extra"><br clear="all"><div><div class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><font color="#999999"><br></font></div><div><font color="#999999">---</font></div><div><font color="#999999">Gregory Bataille</font><br></div></div></div></div>
<br><div class="gmail_quote">On Tue, Apr 25, 2017 at 3:41 AM, John W. Glendening <span dir="ltr"><<a href="mailto:glendening@drjack.net" target="_blank">glendening@drjack.net</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Finally having some success using ImageMagick convert, I backed up by<br>
not using its -Truecolor flag, i.e. using only a -depth 8 flag, which<br>
produced a 4 band RGBA. Creating a .vrt and running gdal2tiles.py<br>
produced successful results, _without_ needing the -a 0,0,0,0<br>
argument. I then pushed things further by adding the partial opacity<br>
polygons back in. That did produce partial opacity polygons in the<br>
tiles, but instead of being magenta they were gray. Don't know how to<br>
explain that, probably a limitation in gdal2tiles.py - but it is at<br>
least partial success.<br>
<br>
Summary: IM convert produced a "UInt16" format TIF when lines are<br>
drawn on its blank transparent canvas, whereas drawing them on a<br>
pre-created background map image produced "Byte" format TIFs. The<br>
gdalbuildvrt understood that and so indicated in the .vrt file it<br>
produced. But gdal2tiles.py apparently only understands "Byte" format<br>
files. The IM convert requires a "-depth 8" flag to produce such<br>
files.<br>
<span class="HOEnZb"><font color="#888888"><br>
John Glendening<br>
<br>
<br>
--<br>
</font></span><div class="HOEnZb"><div class="h5">John W. (Jack) Glendening 831-484-6929<br>
25953 Deer Run Lane Salinas, CA 93908<br>
<br>
</div></div></blockquote></div><br></div>