2016.11.14 22:44 "Re: [Tiff] Right way to make a multi-resolution pyramid", by John

Hi Kemp,

On 14 November 2016 at 18:16, Kemp Watson <kemp@objectivepathology.com> wrote: > What is the “correct” or canonical way to make a (tiled) multi-resolution pyramid in TIFF?

Most implementations seen simply chain top-level IFDs together, I’ve

starting with the base or full-res layer, and going smaller from there to

the apex. this seems wrong to me.

Yes, that what vips has done since the mid 90s, and imagemagick as well. It's also the layout used by things like iipimage and most of the virtual microscopy people. The only other thing they do is set FILETYPE_REDUCEDIMAGE.

I remember experimenting with nested images, which does look cleaner, but compatibility problems made it difficult to work with. TIFF is complicated enough already, and really very few readers will be happy with something like that. As Even says, I think there were problems getting libtiff itself to write them, making the easy route even more appealing.

John