IM 7 -background transparent

[dognose]

Was using this in IM 6

How do i get a transparent background?

flower.jpg


convert flower.jpg -background transparent -shear 12x0 png:output.png

im 6.7.2


img 7.0.8

[snibgo]

You need to enable alpha:

Code: Select all

magick flower.jpg -alpha set -background transparent -shear 12x0 out.png

[dognose]

Ok, that works, but it's weird that in other places I use -background transparent it works without -set alpha!?

[snibgo]

I suppose in those other cases alpha is already enabled. If the input image has any transparency, alpha will certainly be enabled.

[dognose]

for example

convert flower.jpg -background transparent -rotate 45 out.png

will have a transparent background

you'd think setting a color to transparent would enable alpha.. or some consistency.

Anyway thanks for tip!