convert -transparent didn't work on my server.

[lhjava]

I try to make black color transparent within one png format image.

/usr/bin/convert -transparent black input.png output.png

this command can get what I want on windows computer but it can't on my hosting server(Linux).

any one can help me fill out this problem?
thank you very much.

[anthony]

You need two things to make black transpartent. the operator whcih you have, and the alpha channel in the image, which you presumabky do not.

Try this, which has also been argument order corrected, to read the image BEFORE trying to modify it, (without using the legacy support).

Code: Select all

   convert input.png -matte -transparent black output.png

Enjoy.