use set_type add other custom meta data

[chengdonglin]

I am trying to add custom metadata to an existing TIFF file using pyvips. However, after adding the metadata, the file size increases significantly (from 50MB to 700MB), and the resulting TIFF file becomes unreadable by OpenSlide.

import pyvips
#
image = pyvips.Image.new_from_file("D:\\data\\example.tif")

image.set_type(pyvips.GValue.gstr_type, "hello", "xxx")

image.write_to_file("output.tif")

any some method to complete this feature?

[jcupitt]

Hello @chengdonglin,

libtiff does not support custom metadata, you'll need to think of some other way to do what you want. For example, OME-TIFF uses a block of XML in the IMAGEDESCRIPTION tag, perhaps you could add something to that.

image.write_to_file("output.tif")

libvips does not keep track of format settings, so if you want to write as an OME-TIFF, you need to set all the flags yourself.