2019.03.30 13:43 "Re: [Tiff] combining TIFF images, not multi-page", by Roger Leigh

On 30/03/2019 12:44, Paul Hemmer wrote:

> Thanks Bob.

As to the "low RAM footprint way" - in fact I am hoping to use the hard-drive instead of RAM. This is why I have a folder full of small partial images in the first place.

Even with a pyramidal representation, if I'm talking about a final image that may be several hundred gigabytes (or larger) in size, I could never assemble it all in memory in order to write the bottom layer of that pyramid. Can each resolution level be written in "tile by tile" or even line by line? Does this require a different API (like the ImageMagick API?) I assume as well that BigTIFF can be a tiled pyramid?

BigTIFF can absolutely support tiled pyramid images. Several of us here are using libtiff for exactly this purpose.

You can write each resolution level tile-by-tile. Set the number of SubIFDs on the top-level full size image, then write sequential reductions as the following images. Each resolution level can have its own tile size being a separate IFD, though it's common to keep them the same size.

Kind regards,

Roger