'paste' an image over another + transparent

[myspacee]

Hello,
i must script a tool that takes some white symbols over an image:


I've post symbol and image here:
http://static.repubblica.it/laprovincia ... xx/fog.bmp
http://static.repubblica.it/laprovincia ... x/back.bmp

How i can join these 2 image, convert 'green' color in transparent, and obtain final image ?
(arrow show my final wish; green is converted in trasparent color)

thank you for any help,
m.

[snibgo]

Windows syntax:

Code: Select all

convert ^
  back.bmp ^
  ( fog.bmp +transparent White -resize 100x100 ) ^
  -geometry +150+230 ^
  -composite ^
  bf.bmp

Adjust resize and geometry as required.

[myspacee]

thank you!
m.