how to create a completely transparent png?

[linjuming]

how to create a completely transparent png?

convert -size 200x100 xc:transparent img/selected_overlay/selected_overlay.png (black color)
convert -size 200x100 xc:none img/selected_overlay/selected_overlay.png (black color)
convert -size 200x100 img/selected_overlay/selected_overlay.png (error)

[anthony]

there was a few versions that had problems in PNG output due to re-development work.

Upgrade to the very latest.

[fmw42]

this works just fine on IM 6.6.8.4 Q16 Mac OSX Tiger

convert -size 200x100 xc:none tmp.png

[linjuming]

thank you , so I will update the vesion ,hope i will help.

[fmw42]

try on your current version

convert -size 200x100 xc:"rgba(0,0,0,0)" PNG32:tmp.png

or

convert -size 200x100 xc:"rgba(0,0,0,0)" -type truecolormatte PNG32:tmp.png

see if that helps before upgrading.

[linjuming]

yes , it works
using "png32:" helps