[−][src]Struct jpeg_decoder::Decoder
JPEG decoder
Methods
impl<R: Read> Decoder<R>
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pub fn new(reader: R) -> Decoder<R>
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Creates a new Decoder
using the reader reader
.
pub fn info(&self) -> Option<ImageInfo>
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Returns metadata about the image.
The returned value will be None
until a call to either read_info
or decode
has
returned Ok
.
pub fn read_info(&mut self) -> Result<(), Error>
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Tries to read metadata from the image without decoding it.
If successful, the metadata can be obtained using the info
method.
pub fn scale(
&mut self,
requested_width: u16,
requested_height: u16
) -> Result<(u16, u16), Error>
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&mut self,
requested_width: u16,
requested_height: u16
) -> Result<(u16, u16), Error>
Configure the decoder to scale the image during decoding.
This efficiently scales the image by the smallest supported scale factor that produces an image larger than or equal to the requested size in at least one axis. The currently implemented scale factors are 1/8, 1/4, 1/2 and 1.
To generate a thumbnail of an exact size, pass the desired size and then scale to the final size using a traditional resampling algorithm.
pub fn decode(&mut self) -> Result<Vec<u8>, Error>
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Decodes the image and returns the decoded pixels if successful.
Auto Trait Implementations
impl<R> Send for Decoder<R> where
R: Send,
R: Send,
impl<R> Sync for Decoder<R> where
R: Sync,
R: Sync,
impl<R> Unpin for Decoder<R> where
R: Unpin,
R: Unpin,
impl<R> UnwindSafe for Decoder<R> where
R: UnwindSafe,
R: UnwindSafe,
impl<R> RefUnwindSafe for Decoder<R> where
R: RefUnwindSafe,
R: RefUnwindSafe,
Blanket Implementations
impl<T> From<T> for T
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impl<T, U> Into<U> for T where
U: From<T>,
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U: From<T>,
impl<T, U> TryFrom<U> for T where
U: Into<T>,
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U: Into<T>,
type Error = !
The type returned in the event of a conversion error.
fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
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impl<T, U> TryInto<U> for T where
U: TryFrom<T>,
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U: TryFrom<T>,
type Error = <U as TryFrom<T>>::Error
The type returned in the event of a conversion error.
fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>
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impl<T> Borrow<T> for T where
T: ?Sized,
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T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
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T: ?Sized,
fn borrow_mut(&mut self) -> &mut T
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impl<T> Any for T where
T: 'static + ?Sized,
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T: 'static + ?Sized,