Struct BlockHasher 

pub struct BlockHasher { /* private fields */ }

Block hash for perceptual image comparison.

Block hash divides the image into blocks and computes a hash based on the average brightness of each block compared to the overall image average.

Algorithm

1. Divide image into NxN blocks
2. Compute average brightness for each block
3. Compute overall image average
4. Set bit to 1 if block average > image average, else 0

Example

use figif_core::hashers::BlockHasher;
use figif_core::traits::FrameHasher;

let hasher = BlockHasher::new();
let hash = hasher.hash_frame(&image);

Implementations

impl BlockHasher

pub fn new() -> Self

Create a new block hasher with default 8x8 hash size.

pub fn with_size(width: u32, height: u32) -> Self

Create a block hasher with custom hash dimensions.

The hash size determines the number of blocks (width * height bits).

pub fn hash_width(&self) -> u32

Get the hash width.

pub fn hash_height(&self) -> u32

Get the hash height.

pub fn hash_bits(&self) -> u32

Get the total hash bits.

Trait Implementations

impl Clone for BlockHasher

fn clone(&self) -> BlockHasher

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for BlockHasher

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

Formats the value using the given formatter.

impl Default for BlockHasher

fn default() -> Self

Returns the “default value” for a type.

impl FrameHasher for BlockHasher

type Hash = ImageHash

The hash type produced by this hasher.

fn hash_frame(&self, image: &RgbaImage) -> Self::Hash

Compute the perceptual hash for a single frame.

fn distance(&self, a: &Self::Hash, b: &Self::Hash) -> u32

Compute the distance between two hashes.

fn name(&self) -> &'static str

Get the name of this hasher for logging/debugging.

fn suggested_threshold(&self) -> u32

Suggested threshold for considering frames as duplicates.