XnView Software

In writing the post I answered my own question - use the -32bits flag...

"C:\Program Files (x86)\XnView\nconvert.exe" -overwrite -add_alpha 255 -merge_alpha -ctype rgba -32bits -out png -clevel 8 -o out.png in.png

I have an indexed PNG, where index 25 is transparent.

Using nconvert, is there a way to convert this to RGBA, where the alpha for the pixels that were index 25 now have an alpha of zero?
-- basically just the image/32bits menu option from XnView

I'm looking for a way to take a RGBA file, where alpha=0 or 255, and make it an indexed PNG where the A=0 values are an index value whose transparency is set to "use transparency".

OK - I feel like I'm missing something. I have a 24-bit PNG that has a background value of 254,254,254 that needs to be made transparent.

I haven't had luck with any combination of the flags below (using nconvert 5.60):L

-ctype rgba
-add_alpha "value" (what is "value" supposed to represent? Can't ...

I'm looking for a way to change a floating point TIFF to an indexed PNG. I need this done in a batch way, so that all input TIFFs are indexed with the same output values. The input images are all single-band.

Is there a way to use a lookup table in nconvert that provides min/max input values, along ...

I've been using nconvert's transpcolor and it has been great - but I can't find the same function/feature within XnView's batch processing dialog/transformations.

I'm using "-transpcolor 254 254 254"

Any suggestions?