How to export to PNG with transparent background

BenoitMetzger

Hi there,

I used the following line of code to export an mxd to PNG 8 bit (i am creating tiles)... BUT i cant seem to set the background to transparent (or No Color)... any clue as to what parameter  i should use?!

arcpy.mapping.ExportToPNG(mxd, pngpath, df, df_export_width = 256, df_export_height = 256, resolution = 70, world_file=False, color_mode = "8-BIT_PALETTE", background_color = "No Color", transparent_color = "No Color")

I read on other forum threads that by setting the background color and transparent color to the same value should do the trick... it does not work in my case.

The data-frame background color is set to Hollow...


Any tips would be great 🙂

markdenil

Feature transparency support in image export has been on the wish list for a long time.
What you seem to want is, also, a partial transparence;
which is even more complicated, and even less likley to be avaliable soon.

You could try using a diagonal line fill over the areas you want partly transparent;
make the lines the color you will set as the transparent background color.
This "should" break up the opaque image into strips, with transparent strips between.

Obviously, the success of this illusion will be zoom dependant.
The trick is to get the line width and spacing right for the zoom you want to optimize.
Thus, you will still see the overlay tile and the underlying base map,
both with enough coherence to make them understandable.

...not, likely, a very good solution.