Correct way to read photometric interpretation?

[aconbere]

What's the intended way to access the photometric interpretation tag? By the time I have a decoder it's been parsed and stored in the Image. But the image field is private and the Decoder doesn't offer a method to access it. Should I just fall back on munging about with tags?

        let photometric_interpretation = tag_reader
            .find_tag(Tag::PhotometricInterpretation)?
            .map(Value::into_u16)
            .transpose()?
            .and_then(PhotometricInterpretation::from_u16)
            .ok_or(TiffUnsupportedError::UnknownInterpretation)?;

[fintelia]

That's probably the best way to get the photometric interpretation at the moment. There's also the option of calling Decoder::colortype to get a processed version.

[aconbere]

@fintelia Ah yeah so I'm already using colortype, in this case I have two tiffs with the same colortype but flipped if zero is black or white is black which isn't encoded into the colortype. Thank you!

[fintelia]

That conversion is actually handled internally:

image-tiff/src/decoder/image.rs

Lines 661 to 663 in 96d3a02

	if photometric_interpretation == PhotometricInterpretation::WhiteIsZero {
	super::invert_colors(tile, color_type, self.sample_format);
	}

[aconbere]

Huh! Thanks for taking the time to answer. I must be dealing with some other issue!