pub struct Reader<R: Read> { /* private fields */ }
Expand description
PNG reader (mostly high-level interface)
Provides a high level that iterates over lines or whole images.
Implementations§
source§impl<R: Read> Reader<R>
impl<R: Read> Reader<R>
sourcepub fn info(&self) -> &Info<'_>
pub fn info(&self) -> &Info<'_>
Get information on the image.
The structure will change as new frames of an animated image are decoded.
sourcepub fn next_frame(
&mut self,
buf: &mut [u8]
) -> Result<OutputInfo, DecodingError>
pub fn next_frame( &mut self, buf: &mut [u8] ) -> Result<OutputInfo, DecodingError>
Decodes the next frame into buf
.
Note that this decodes raw subframes that need to be mixed according to blend-op and dispose-op by the caller.
The caller must always provide a buffer large enough to hold a complete frame (the APNG
specification restricts subframes to the dimensions given in the image header). The region
that has been written be checked afterwards by calling info
after a successful call and
inspecting the frame_control
data. This requirement may be lifted in a later version of
png
.
Output lines will be written in row-major, packed matrix with width and height of the read frame (or subframe), all samples are in big endian byte order where this matters.
sourcepub fn next_row(&mut self) -> Result<Option<Row<'_>>, DecodingError>
pub fn next_row(&mut self) -> Result<Option<Row<'_>>, DecodingError>
Returns the next processed row of the image
sourcepub fn next_interlaced_row(
&mut self
) -> Result<Option<InterlacedRow<'_>>, DecodingError>
pub fn next_interlaced_row( &mut self ) -> Result<Option<InterlacedRow<'_>>, DecodingError>
Returns the next processed row of the image
sourcepub fn output_color_type(&self) -> (ColorType, BitDepth)
pub fn output_color_type(&self) -> (ColorType, BitDepth)
Returns the color type and the number of bits per sample
of the data returned by Reader::next_row
and Reader::frames`.
sourcepub fn output_buffer_size(&self) -> usize
pub fn output_buffer_size(&self) -> usize
Returns the number of bytes required to hold a deinterlaced image frame that is decoded using the given input transformations.
sourcepub fn output_line_size(&self, width: u32) -> usize
pub fn output_line_size(&self, width: u32) -> usize
Returns the number of bytes required to hold a deinterlaced row.