Struct JpegCoefficients 

pub struct JpegCoefficients {
    pub components: Vec<ComponentCoefficients>,
}

Quantized DCT coefficients for all components in a JPEG image.

Returned by read_coefficients and accepted by write_coefficients.

Fields

components: Vec<ComponentCoefficients>

One entry per component, in the order they appear in the JPEG SOF marker (typically Y, Cb, Cr for colour images).

Implementations

impl JpegCoefficients

pub fn eligible_ac_count(&self) -> usize

Count the number of AC coefficients with |v| >= 2 across all components.

Modifying only these coefficients preserves the zero-run structure of the entropy stream, keeping the output a valid JPEG that is perceptually indistinguishable from the original.

Example

use dct_io::read_coefficients;

let jpeg = std::fs::read("photo.jpg").unwrap();
let coeffs = read_coefficients(&jpeg).unwrap();
println!("Eligible AC positions: {}", coeffs.eligible_ac_count());

Trait Implementations

impl Clone for JpegCoefficients

fn clone(&self) -> JpegCoefficients

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for JpegCoefficients

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

Formats the value using the given formatter.