Struct Kernel 

pub struct Kernel { /* private fields */ }

A convolution kernel: odd-sized, square or rectangular, small.

Implementations

impl Kernel

pub const MAX_SIZE: u32 = 63

The largest kernel accepted, per axis.

“Arbitrary small kernels” (SPEC §Core ops) needs a number attached to it. Beyond this a separable or frequency-domain implementation is the right answer, and silently accepting a 999-tap kernel would be an invitation to a very slow surprise.

pub fn new(width: u32, height: u32, taps: &[f32]) -> Result<Kernel, PixelsError>

Build a kernel from width * height taps in row-major order.

Taps are normalized by their sum, so [1; 9] and [1.0/9.0; 9] are the same blur. A kernel summing to zero — an edge detector — is left unnormalized rather than divided by zero.

Errors

Returns PixelsError::InvalidArgument if the dimensions are even or zero, exceed Kernel::MAX_SIZE, disagree with the tap count, or if any tap is not finite.

pub fn square(size: u32, taps: &[f32]) -> Result<Kernel, PixelsError>

A square kernel of size taps per side.

Errors

As Kernel::new.

pub fn blur(size: u32) -> Result<Kernel, PixelsError>

A box blur of size by size.

Errors

As Kernel::new.

pub fn gaussian(sigma: f32) -> Result<Kernel, PixelsError>

A Gaussian blur approximated at sigma, sized to 3 sigma each way.

Errors

Returns PixelsError::InvalidArgument if sigma is not finite and positive, or if the implied kernel exceeds Kernel::MAX_SIZE.

pub fn sharpen(amount: f32) -> Result<Kernel, PixelsError>

A 3x3 sharpen: the identity plus a Laplacian scaled by amount.

Errors

Returns PixelsError::InvalidArgument if amount is not finite.

pub const fn width(&self) -> u32

The kernel width in taps.

pub const fn height(&self) -> u32

The kernel height in taps.

pub const fn radius_x(&self) -> u32

How far the kernel reaches from its centre, horizontally.

pub const fn radius_y(&self) -> u32

How far the kernel reaches from its centre, vertically.

pub fn taps(&self) -> &[f32]

The normalized taps, row-major.

Trait Implementations

impl Clone for Kernel

fn clone(&self) -> Kernel

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Kernel

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

Formats the value using the given formatter.

impl PartialEq for Kernel

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Kernel