Background after waving image using -wave..

[aravs7]

Hi,

Am absolutely new to Imagemagick.

This is what am trying to do:
I am trying to modify and bend an image along a sine wave (to create an arc of that image) and then place it on a cylindrical surface image like a cup, so that the image appears to be printed on the cup.

Problem: I am able to bend the image using -wave and make it an arc. But the displaced pixels, i.e the place above and below the actual image have some color. When i use background -none the background shows up in black. I want no background after waving the image. Want something like a transparent png image which can be used on web pages.

I guess i was clear explainging my point. Need help. Please let me know if something was unclear

Thanks,
Aravind

[fmw42]

be sure to use png or gif for your output. jpg does not support transparency

you may want to look at my unix bash script, cylinderize, see link below

[anthony]

FYI, see also the example in IM examples, Image Mapping Effects
http://www.imagemagick.org/Usage/mappin ... e_cylinder

[fmw42]

When i use background -none the background shows up in black

try -background none

but looks like a bug as it works with any color but "none"

[anthony]

If 'none' turns up as transparency, you need to make sure your image has transparency.
Ass a -matte or -alpha on afetr reading the source image.

You may also need -channel RGBA or -channel All setting for soem operators to handle transparency as well as colors.

[fmw42]

this works fine.

convert koala.gif -background none -wave 10x64 wave.png


Note you have to use png or gif and not jpg as jpg does not support transparency.