compressing TIFF without loosing the layers

[lriou]

hello everyone,
I'm very new to this. I'm trying to gain space on a HD by compressing every tiff file on the drive. I've allready spent hours fixing the recursive dos script and make everything work, but now I'm lost. Output files are compressed as I need, but I loose layers : the file is flattened : only the background is left.

I use this command :
convert -compress lzw [filename] [filename]

If there is there any simple switch to prevent the merging, I can't find it.

Has anyone any clue about this ?
thanks.

[fmw42]

have you tried

convert filename -compress lzw filename

see http://www.imagemagick.org/Usage/formats/#tiff

for further info about Tiff