irregular montage

[anthony]

I think a rough example may be in order.

Note you can leave a 'gap' in the montage grid using a "NULL:" image, but you can't specify an image to fill two cells vertically or horizontally, like you can with HTML.

See IM Examples, Montage for details.

Maybe you can DIY the montage using various type of -append.
See IM Examples, Mosaics of Images.

Those example also show four different technique in which you can even do DIY placement of the image in any position on canvases.