Enum Orientation 

pub enum Orientation {
    Upright,
    FlipHorizontal,
    Rotate180,
    FlipVertical,
    Transpose,
    Rotate90,
    Transverse,
    Rotate270,
}

How the stored pixels must be transformed to be shown the right way up.

The eight EXIF orientation values, named for what they do rather than numbered — Rotate90 is what value 6 means, and nobody remembers that.

Variants

Upright

Value 1: already upright. Also what a file with no EXIF gets.

FlipHorizontal

Value 2.

Rotate180

Value 3.

FlipVertical

Value 4.

Transpose

Value 5.

Rotate90

Value 6 — the common one: a phone held upright.

Transverse

Value 7.

Rotate270

Value 8.

Implementations

impl Orientation

pub fn from_exif(value: u16) -> Orientation

From the raw EXIF value. Anything outside 1..=8 is Orientation::Upright — a corrupt tag must not turn a picture sideways, and “no opinion” is the safe reading of a value nobody defined.

pub fn swaps_axes(self) -> bool

Whether applying this swaps width and height.

The half of orientation that is easy to forget, because it is not about pixels: a fit-to-window computed on the stored dimensions of a phone photograph fits the wrong rectangle, and the picture is letterboxed on the wrong axis before anyone notices it is also sideways.

pub fn applied_size(self, width: u32, height: u32) -> (u32, u32)

The size a picture presents after this orientation is applied.

pub fn as_image(self) -> Orientation

The equivalent image operation, which is what actually moves the pixels. Delegated rather than hand-rolled: image::metadata::Orientation is the same eight cases, and DynamicImage::apply_orientation is tested by people who do only this.

Trait Implementations

impl Clone for Orientation

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for Orientation

impl Debug for Orientation

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Orientation

fn default() -> Self

Returns the “default value” for a type.

impl Eq for Orientation

impl PartialEq for Orientation

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Orientation