Convert to grayscale , keep transparency

[mdibango]

Hi ,

My problem is that i don't see how to convert a png image with a transparent background and keeping it transparent.
With

Code: Select all

convert -type Grayscale "picture.png" "picture_nb.png"

transparency become black background.

If anyone can help.

Thank you

[fmw42]

here is an example

create color image with transparent background

convert logo: -transparent white logot.png

change to gray with transparent background

convert logot.png -colorspace gray logotg.png

or

convert logot.png -channel RGBA -matte -colorspace gray logotg.png

[mdibango]

It's working

thanks a lot

[anthony]

http://imagemagick.org/Usage/color/#grayscale
for many different ways!