Struct PngDecoder 

pub struct PngDecoder<S>
where
    S: Source,
{ /* private fields */ }

Decodes a PNG stream.

Implementations

impl<S> PngDecoder<S>

where S: Source,

pub fn new(source: S, limits: Limits) -> Result<PngDecoder<S>, PixelsError>

Parse the signature, IHDR and every chunk before the image data.

Errors

Returns PixelsError::Malformed for a bad signature, header or pre-IDAT chunk, or PixelsError::LimitExceeded if the dimensions exceed limits.

pub const fn header(&self) -> Header

The parsed header.

Trait Implementations

impl<S> Debug for PngDecoder<S>

where S: Debug + Source,

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

Formats the value using the given formatter.

impl<S> Decoder for PngDecoder<S>

where S: Source + Debug,

fn orientation(&self) -> Orientation

From an eXIf chunk before the image data. One after it is not seen: by then the pipeline has been built, and §5.6 puts eXIf first.

fn icc_profile(&self) -> Option<&[u8]>

From an iCCP chunk before the image data.

fn descriptor(&self) -> ImageDescriptor

The shape of the image, known after the header is parsed.

fn capability(&self) -> DecodeCapability

What this decoder can produce without a full decode.

fn read_row(&mut self, out: &mut [u8]) -> Result<(), PixelsError>

Decode the next row, top to bottom, into out.

fn animation(&self) -> Option<Animation>

The source’s animation, if it has more than one frame.

fn read_region( &mut self, region: Region, out: &mut TileMut<'_>, ) -> Result<(), PixelsError>

Decode an arbitrary region into out.

fn reduced_descriptor(&self, target: (u32, u32)) -> Option<ImageDescriptor>

What this decoder would produce if asked for target or larger, when the format lets it reach that size more cheaply than a full decode.

fn reduce_to(&mut self, descriptor: ImageDescriptor) -> Result<(), PixelsError>

Commit to producing descriptor, which Decoder::reduced_descriptor must have returned.