add background image to multiple images

[mentose457]

Thanks in advance for the help. Ive been going nuts over this for a few hours.

What I want to do is add a background image to a bunch of images while preserving the file name of the image that gets the background. So I'd like to use mogrify.

The image I want to use as the background image is simply called 'bg.png'. Note that parts of the image are transparent and semi-transparent.

The images I want to add the background to have a transparent background. They are named ic_*.png. Again I'd like to preserve the name of these images.

All of the images are the same dimensions, 128x128.

There is a bunch of fantastic info on convert but not too much on mogrify.

The version of ImageMagick im on is 6.7.7-10 2014-03-06 Q16

Again, thanks for any help.

Brent

[fmw42]

you will need to use alpha compositing via -draw with mogrify as described at http://www.imagemagick.org/Usage/basics ... fy_compose

You just need to find the correct compose method. See http://www.imagemagick.org/Usage/compose/#duff-porter

If you cannot figure it out, post one pair of images to dropbox.com and put the URLs here. Then we can try to help.

Note that IM 6.7.7.10 is rather old and right when IM was undergoing major changes. It is about 130 versions old. You should consider upgrading.

[snibgo]

"convert" can do the job in a single command, but the output filename will usually be wrong.

Code: Select all

convert ic_*.png null: bg.png -composite out_%06.png

Output files will be named out_000000.png, out_000001.png, etc.

We can use a bit of magic:

Code: Select all

convert *.png -set filename:myname %t null: red.tiff -layers composite %[filename:myname].jpg

Now the outputs will have the same name as the inputs, but jpg instead of png. If I used png outputs, they would overwrite the inputs.

[mentose457]

Thanks fmw42. I got it. this is what ended up with:

Code: Select all

mogrify -alpha Set -draw 'image Dst_Over 0,0 0,0 "bg.png"' *.png

I also found out some of my images were not the correct size so I did this as well:

Code: Select all

mogrify -gravity center -background transparent -extent 128x128  *.png

The annoying thing is I tried something like that the other day when attempting to modify the info from a tutorial on how to add a watermark to an image.

[fmw42]

try putting them together as

Code: Select all

mogrify -gravity center -background transparent -extent 128x128 -alpha Set -draw 'image Dst_Over 0,0 0,0 "bg.png"' *.png

does that work?

[mentose457]

try putting them together as

Code: Select all

mogrify -gravity center -background transparent -extent 128x128 -alpha Set -draw 'image Dst_Over 0,0 0,0 "bg.png"' *.png

does that work?

Thanks that also worked.