how to set the opecity when composimg png files?

[linjuming]

how to set the top png file's opacity when it is composed on top to the background png file? like the same work in PS.

[linjuming]

the command line below can set the opacity for top png when "-compose dissolve" :
convert 1.png 2.png -alpha on -compose dissolve -define compose:args=50 -composite hello.png

but there is no use when "-compose overlay" :
convert 1.png 2.png -alpha on -compose overlay -define compose:args=50 -composite hello.png

[linjuming]

refer to this post:
viewtopic.php?f=1&t=17503&p=65756&hilit=opacity#p65756

source psd file description:


source png files:



my code:

Code: Select all

convert 1.png ( 2.png -alpha set -channel A -evaluate set 40% ) -compose overlay -composite hello.png

result: hello.png


the result is the same with the 1.png? why

[linjuming]

[fmw42]

On windows you do not escape the ( ) with \, just use the parenthesis alone. Please read http://www.imagemagick.org/Usage/windows/

[linjuming]

Thanks ,and why can not i create the right result using this code?

Code: Select all

convert 1.png ( 2.png -alpha set -channel A -evaluate set 40% ) -compose overlay -composite hello.png

[fmw42]

convert 1.png ( 2.png -alpha set -channel A -evaluate set 40% ) -compose overlay -composite hello.png

try

convert 1.png ( 2.png -alpha set -channel A -evaluate set 40% ) -compose over -composite hello.png

You must have a space after ( and before ).


This works for me on my Mac/Unix system and looks similar to your PS result:

convert 1.png \( 2.png -alpha set -channel A -evaluate set 40% \) -compose over -composite result.png

[linjuming]

convert 1.png ( 2.png -alpha set -channel A -evaluate set 40% ) -compose over -composite hello.png

result still as the same as 1.png
I made sure that space before and after ( ) ,the code is compeletely copyed from your code.

seems many problem running at my end ....

[linjuming]

[fmw42]

what version of IM are you using?

identify -version

[fmw42]

run the command line in a command window by typing or pasting and not from a Bat file.

[linjuming]

[linjuming]

So,finally, it must be the problem with my text editor "notepad++".
by the way, what is the time at your end now? for sometimes i post probems at daytime but no one reply.

[fmw42]

I am on the west coast of the US and the time now is 9 PM (GMT-8).

[linjuming]

Thanks a million , now is 1 pm at my end.