[Octave-bug-tracker] [bug #43495] Crash when reading large TIFF with imread()

[Carnë Draug]

Follow-up Comment #14, bug #43495 (project octave):

Your build of GraphisMagick may be the limitation here. The way you built it
can change your results. On my case, it's built with quantum 16 so it reads it
as uint16 image (and probably RGB as well). Octave receives it and changes it
back into what it really is, a logical matrix. In your case, it may be reading
it as an uint8 RGB image.

Ideally, you'd implement the missing Tiff class which would simply be a
wrapper to libtiff. This allows for a finer control while reading the image
file. This requires classdef will be released with Octave 4.2.

Alternatively, you can:

1) try using the "PixelRegion" of imread() to read it in blocks and make your
image out of its pieces. Use iminfo to get the image size, and then fill it in
blocks.

2) implement a tiff reader for your files. I've done it before to read very
special Tiffs. It's not that hard and there's plenty of examples on the
internet written as m files (writing a general tiff is hard, but writing for a
very specific subset can be really easy).

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