Struct MultiHashFingerprint 

pub struct MultiHashFingerprint { /* private fields */ }

A multi-algorithm fingerprint containing hashes from multiple perceptual algorithms.

Provides enhanced similarity detection by combining results from multiple hash algorithms with weighted combination for improved accuracy.

Binary layout

#[repr(C)] with no padding bytes (536 bytes total: 32 + 3 × 168). Implements bytemuck::Pod / bytemuck::Zeroable for zero-copy cast to &[u8]. See ImageFingerprint for an example.

Stable layout is enforced at compile time via a const _ size assertion; any accidental layout drift fails the build.

Copy is derived for bytemuck::Pod compatibility; move-by-value silently memcpys 536 bytes. Prefer borrowing (&MultiHashFingerprint) in hot loops.

Implementations

impl MultiHashFingerprint

pub fn exact_hash(&self) -> &[u8; 32]

Returns the BLAKE3 hash of the original image bytes.

pub const fn format_version() -> u32

Returns the on-disk format version this fingerprint was computed under.

Equal to crate::FORMAT_VERSION. Persist alongside fingerprint bytes (or in a sidecar manifest) and refuse comparison across mismatched versions to guard against algorithm-version drift.

pub fn ahash(&self) -> &ImageFingerprint

Returns the AHash-based fingerprint.

pub fn phash(&self) -> &ImageFingerprint

Returns the PHash-based fingerprint.

pub fn dhash(&self) -> &ImageFingerprint

Returns the DHash-based fingerprint.

pub fn get(&self, algorithm: HashAlgorithm) -> &ImageFingerprint

Returns the fingerprint for a specific algorithm.

pub fn compare(&self, other: &MultiHashFingerprint) -> Similarity

Compares two multi-hash fingerprints using the default weighted combination.

Equivalent to compare_with_config called with MultiHashConfig::default():

• 10% AHash / 60% PHash / 30% DHash per-algorithm blend
• Within each algorithm, 40% global hash + 60% block-level hashes
• Block distance threshold of 32 (Hamming, out of 64)

Use compare_with_config to tune any of these.

pub fn compare_with_threshold( &self, other: &MultiHashFingerprint, block_threshold: u32, ) -> Similarity

Compares two multi-hash fingerprints with a custom block distance threshold.

Arguments

• other - The fingerprint to compare against
• block_threshold - Maximum Hamming distance for a block to count as a match (0-64). Lower = stricter (fewer blocks qualify), higher = looser. Default is 32.

pub fn compare_with_config( &self, other: &MultiHashFingerprint, config: &MultiHashConfig, ) -> Similarity

Compares two multi-hash fingerprints using a fully configurable weight and threshold set.

All knobs from MultiHashConfig are honored; defaults reproduce compare. See MultiHashConfig for examples.

pub fn is_similar(&self, other: &MultiHashFingerprint, threshold: f32) -> bool

Checks if this fingerprint is similar to another within a threshold.

Uses the weighted combination score from compare().

Panics

Panics in debug mode if threshold is not in [0.0, 1.0]. In release mode, out-of-range or NaN thresholds return false.

Trait Implementations

impl Clone for MultiHashFingerprint

fn clone(&self) -> MultiHashFingerprint

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MultiHashFingerprint

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for MultiHashFingerprint

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Hash for MultiHashFingerprint

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for MultiHashFingerprint

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for MultiHashFingerprint

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Zeroable for MultiHashFingerprint

fn zeroed() -> Self

Calls zeroed.

impl Copy for MultiHashFingerprint

impl Eq for MultiHashFingerprint

impl Pod for MultiHashFingerprint

impl StructuralPartialEq for MultiHashFingerprint