Struct Exif

pub struct Exif { /* private fields */ }

A struct that holds the parsed Exif attributes.

Examples

// Get a specific field.
let xres = exif.get_field(Tag::XResolution, In::PRIMARY)?;
assert_eq!(xres.display_value().with_unit(&exif).to_string(),
           "72 pixels per inch");
// Iterate over all fields.
for f in exif.fields() {
    println!("{} {} {}", f.tag, f.ifd_num, f.display_value());
}

Implementations

impl Exif

pub fn buf(&self) -> &[u8]

Returns the slice that contains the TIFF data.

pub fn fields(&self) -> impl ExactSizeIterator<Item = &Field>

Returns an iterator of Exif fields.

Examples found in repository

examples/dumpexif.rs (line 59)

fn dump_file(path: &Path) -> Result<(), exif::Error> {
    let file = File::open(path)?;

    // To parse strictly:
    // let exif = exif::Reader::new()
    //     .read_from_container(&mut BufReader::new(&file))?;

    // To parse with continue-on-error mode:
    let exif = exif::Reader::new()
        .continue_on_error(true)
        .read_from_container(&mut BufReader::new(&file))
        .or_else(|e| e.distill_partial_result(|errors| {
            eprintln!("{}: {} warning(s)", path.display(), errors.len());
            errors.iter().for_each(|e| eprintln!("  {}", e));
        }))?;

    println!("{}", path.display());
    for f in exif.fields() {
        println!("  {}/{}: {}",
                 f.ifd_num.index(), f.tag,
                 f.display_value().with_unit(&exif));
        println!("      {:?}", f.value);
    }
    Ok(())
}

pub fn little_endian(&self) -> bool

Returns true if the Exif data (TIFF structure) is in the little-endian byte order.

pub fn get_field(&self, tag: Tag, ifd_num: In) -> Option<&Field>

Returns a reference to the Exif field specified by the tag and the IFD number.

Examples found in repository

examples/reading.rs (line 48)

fn main() {
    let file = File::open("tests/exif.jpg").unwrap();
    let exif = Reader::new().read_from_container(
        &mut BufReader::new(&file)).unwrap();

    // To obtain a string representation, `Value::display_as`
    // or `Field::display_value` can be used.  To display a value with its
    // unit, call `with_unit` on the return value of `Field::display_value`.
    let tag_list = [Tag::ExifVersion,
                    Tag::PixelXDimension,
                    Tag::XResolution,
                    Tag::ImageDescription,
                    Tag::DateTime];
    for tag in tag_list {
        if let Some(field) = exif.get_field(tag, In::PRIMARY) {
            println!("{}: {}",
                     field.tag, field.display_value().with_unit(&exif));
        }
    }

    // To get unsigned integer value(s) from either of BYTE, SHORT,
    // or LONG, `Value::get_uint` or `Value::iter_uint` can be used.
    if let Some(field) = exif.get_field(Tag::PixelXDimension, In::PRIMARY) {
        if let Some(width) = field.value.get_uint(0) {
            println!("Valid width of the image is {}.", width);
        }
    }

    // To convert a Rational or SRational to an f64, `Rational::to_f64`
    // or `SRational::to_f64` can be used.
    if let Some(field) = exif.get_field(Tag::XResolution, In::PRIMARY) {
        match field.value {
            Value::Rational(ref vec) if !vec.is_empty() =>
                println!("X resolution is {}.", vec[0].to_f64()),
            _ => {},
        }
    }

    // To parse a DateTime-like field, `DateTime::from_ascii` can be used.
    if let Some(field) = exif.get_field(Tag::DateTime, In::PRIMARY) {
        match field.value {
            Value::Ascii(ref vec) if !vec.is_empty() => {
                if let Ok(datetime) = DateTime::from_ascii(&vec[0]) {
                    println!("Year of DateTime is {}.", datetime.year);
                }
            },
            _ => {},
        }
    }
}