PNG and TIFF XMP

[trougnouf]

What did you do?

Download a PNG file with exif data, for example https://commons.wikimedia.org/wiki/File:Ares_Tower_Vienna_from_SW_on_2015-07-10.png (direct link: https://upload.wikimedia.org/wikipedia/commons/5/5c/Ares_Tower_Vienna_from_SW_on_2015-07-10.png )

from PIL import Image
infpath = 'Ares Tower Vienna from SW on 2015-07-10.png'
pilimg = Image.open(infpath)
exifdata = pilimg._getexif()

What did you expect to happen?

exifdata[34855] == 100 # ISO sensitivity

See alse: #3674

What actually happened?

exifdata is None.

pilimg.info has the following keys: ['dpi', 'icc_profile', 'XML:com.adobe.xmp', 'chromaticity']; XML:com.adobe.xmp contains all of the info, but it is a very messy xml string.

What are your OS, Python and Pillow versions?

• OS: Arch Linux
• Python: 3.9.5
• Pillow: 8.2.0

On a side note I can't get exif info directly from a tiff file either, _getexif() then raises an AttributeError. egfile: https://commons.wikimedia.org/wiki/File:Book_of_Hours_(Use_of_Metz)_Fol._27r,_Decorated_Initials.tif (direct: https://upload.wikimedia.org/wikipedia/commons/1/16/Book_of_Hours_%28Use_of_Metz%29_Fol._27r%2C_Decorated_Initials.tif )

[radarhere]

If I run exiftool -v over your PNG, I find that ISO is not within an eXIf chunk, but within a iTXt chunk, 'XMP directory' - as you've already figured out in a different way. So my conclusion is that the information you're after is not technically EXIF.

In 8.2.0 (#5144), we added getxmp() for JPEG images, to present XMP info in a nicer form. If we added that method for PNG as well, does that sound like a good solution?

[radarhere]

As for your TIFF image, as the error says, Pillow doesn't have a _getexif() method for TIFF.
I'm guessing that the information you're after is in the Image.open('sample.tif').tag_v2 dictionary.
You may also be interested in #5416, a pending PR to allow the tag_v2 data to be accessed through getexif().

[trougnouf]

In 8.2.0 (#5144), we added getxmp() for JPEG images, to present XMP info in a nicer form. If we added that method for PNG as well, does that sound like a good solution?

Yes, that would be pretty ideal :) Anything that uniformizes tag access across different formats is a step in the right direction imo.

It would be nice to have it accessible through the same method with tiff tag_v2 data as well.

[radarhere]

I've added getxmp() methods for PNG and TIFF into #5455. See what you think.

[radarhere]

Pillow 8.3.0 has now been released with this new feature.

However, be aware that you will have to install defusedxml to get it to work. See #5565 for more information