Crate exif

Expand description

This is a pure-Rust library to parse Exif data.

This library parses Exif attributes in a raw Exif data block. It can also read Exif data directly from some image formats including TIFF, JPEG, HEIF, PNG, and WebP.

Examples

To parse Exif attributes in an image file, use Reader::read_from_container. To convert a field value to a string, use Field::display_value.

for path in &["tests/exif.jpg", "tests/exif.tif"] {
    let file = std::fs::File::open(path)?;
    let mut bufreader = std::io::BufReader::new(&file);
    let exifreader = exif::Reader::new();
    let exif = exifreader.read_from_container(&mut bufreader)?;
    for f in exif.fields() {
        println!("{} {} {}",
                 f.tag, f.ifd_num, f.display_value().with_unit(&exif));
    }
}

To process a field value programmatically in your application, use the value itself (associated value of enum Value) rather than a stringified one.

// Orientation is stored as a SHORT.  You could match `orientation.value`
// against `Value::Short`, but the standard recommends that readers
// should accept BYTE, SHORT, or LONG values for any unsigned integer
// field.  `Value::get_uint` is provided for that purpose.
match exif.get_field(Tag::Orientation, In::PRIMARY) {
    Some(orientation) =>
        match orientation.value.get_uint(0) {
            Some(v @ 1..=8) => println!("Orientation {}", v),
            _ => eprintln!("Orientation value is broken"),
        },
    None => eprintln!("Orientation tag is missing"),
}
// XResolution is stored as a RATIONAL.
match exif.get_field(Tag::XResolution, In::PRIMARY) {
    Some(xres) =>
        match xres.value {
            Value::Rational(ref v) if !v.is_empty() =>
                println!("XResolution {}", v[0]),
            _ => eprintln!("XResolution value is broken"),
        },
    None => eprintln!("XResolution tag is missing"),
}