pub struct BiLevel;
Expand description

A bi-level color map

Examples

use image::imageops::colorops::{index_colors, BiLevel, ColorMap};
use image::{ImageBuffer, Luma};

let (w, h) = (16, 16);
// Create an image with a smooth horizontal gradient from black (0) to white (255).
let gray = ImageBuffer::from_fn(w, h, |x, y| -> Luma<u8> { [(255 * x / w) as u8].into() });
// Mapping the gray image through the `BiLevel` filter should map gray pixels less than half
// intensity (127) to black (0), and anything greater to white (255).
let cmap = BiLevel;
let palletized = index_colors(&gray, &cmap);
let mapped = ImageBuffer::from_fn(w, h, |x, y| {
    let p = palletized.get_pixel(x, y);
    cmap.lookup(p.0[0] as usize)
        .expect("indexed color out-of-range")
});
// Create an black and white image of expected output.
let bw = ImageBuffer::from_fn(w, h, |x, y| -> Luma<u8> {
    if x <= (w / 2) {
        [0].into()
    } else {
        [255].into()
    }
});
assert_eq!(mapped, bw);

Trait Implementations§

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impl Clone for BiLevel

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fn clone(&self) -> BiLevel

Returns a copy of the value. Read more
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fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
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impl ColorMap for BiLevel

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fn has_lookup(&self) -> bool

Indicate NeuQuant implements lookup.

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type Color = Luma<u8>

The color type on which the map operates on
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fn index_of(&self, color: &Luma<u8>) -> usize

Returns the index of the closest match of color in the color map.
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fn lookup(&self, idx: usize) -> Option<Self::Color>

Looks up color by index in the color map. If idx is out of range for the color map, or ColorMap doesn’t implement lookup None is returned.
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fn map_color(&self, color: &mut Luma<u8>)

Maps color to the closest color in the color map.
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impl Copy for BiLevel

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Blanket Implementations§

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> ToOwned for T
where T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.