OSX Software to use for Photo Collage in a large poster size I need a very large poster of pictures of kids collage.

Here is a sample

I'm not a graphic designer and so I'm not necessarily very familiar with the Vector design tools that people often use to make these kinds of posters.

I came up with this from a free tool, but that only allows exporting of sizes below 172" and my requirement is to edit and export this for size 298" X 121"

Can anyone recommend me a good collaging poster export tool that exports to this size?
Vector graphics won't help for this kind of task. All your images are in raster format.
Your limit will really be the number of pixels [WxH] rather than 'print size', though you will need at least 150 dpi to print this at a large poster size.

Gimp can apparently save images up to 45,000 x 45,000 pixels [though I can't find citation for this] which should be just inside your range - though bear in mind this will be a colossal size in RAM.

The clarity of your output image is also very dependant on you input sizes. If you need to enlarge the photos to fit this size you will lose definition.



Alternatively, if your existing package will let you export at 300dpi or higher, then you can just ask your print service to re-scale.