Struct PngEnvelope 

pub struct PngEnvelope { /* private fields */ }

The shape of the file a container arrived in.

Travels with the samples it was read from — see crate::image_io::buffer::ImageBuffer::envelope — so that the writing side can reproduce it without any intermediate layer having to carry it.

Implementations

impl PngEnvelope

pub fn preserved_chunks(&self) -> &[PreservedChunk]

The whitelisted chunks, in the order they will be written.

pub fn idat_chunk_size(&self) -> usize

Bytes of compressed pixel data per IDAT chunk.

pub fn idat_chunk_count(&self) -> usize

How many IDAT chunks the container was read from.

Zero for an envelope that was chosen rather than observed, which is the case for every container this crate draws itself.

pub fn discarded_chunks(&self) -> usize

Ancillary chunks that were present and will not be reproduced.

The size of the residue, in the only unit that can be counted without keeping the chunks themselves: this is what a reader would notice missing from the file, and most of it is the metadata that is dropped on purpose.

Trait Implementations

impl Clone for PngEnvelope

fn clone(&self) -> PngEnvelope

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PngEnvelope

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

Formats the value using the given formatter.