Struct pix::Palette

pub struct Palette<F> where
    F: Format<Chan = Ch8>,  { /* fields omitted */ }

Color table for use with indexed Rasters.

Methods

impl<F> Palette<F> where
    F: Format<Chan = Ch8>, 

pub fn new(capacity: usize) -> Self

Create a new color Palette.

• capacity Maximum number of entries.

pub fn len(&self) -> usize

Get the number of entries.

pub fn set_threshold_fn(&mut self, threshold_fn: fn(_: usize) -> F)

Set the threshold function for matching entries.

• threshold_fn Called when checking whether a color matches an existing entry. The parameter is the palette table size. Returns the maximum Channel-wise difference to match.

pub fn as_u8_slice(&self) -> &[u8]

Get view of Palette as a u8 slice.

pub fn entry(&self, i: usize) -> Option<F>

Get a Palette entry.

• i Index of entry.

pub fn set_entry(&mut self, clr: F) -> Option<usize>

Set a Palette entry.

The table is searched for the best matching color within the threshold. If none found, a new entry is added.

• clr Color to lookup or add.

Returns

Index of best matching or added entry if successful. Otherwise, when no matches are found and the table is full, None is returned.

pub fn replace_entry(&mut self, i: usize, clr: F) -> Option<F>

Replace a Palette entry.

• i Index of entry.
• clr Color to replace entry with.

Returns

Previous entry, or None if index is larger than table size.

pub fn histogram<T>(&self, ent: &[T]) -> Option<Vec<usize>> where
    T: Copy,
    usize: From<T>, 

Create a histogram of Palette entries.

• ent Slice of entry indices (pixel values).

Trait Implementations

impl<F: Clone> Clone for Palette<F> where
    F: Format<Chan = Ch8>, 

fn clone(&self) -> Palette<F>

Returns a copy of the value.

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

Performs copy-assignment from source.