Struct image::codecs::jpeg::JpegEncoder

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pub struct JpegEncoder<W> { /* private fields */ }
Expand description

The representation of a JPEG encoder

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impl<W: Write> JpegEncoder<W>

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pub fn new(w: W) -> JpegEncoder<W>

Create a new encoder that writes its output to w

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pub fn new_with_quality(w: W, quality: u8) -> JpegEncoder<W>

Create a new encoder that writes its output to w, and has the quality parameter quality with a value in the range 1-100 where 1 is the worst and 100 is the best.

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pub fn set_pixel_density(&mut self, pixel_density: PixelDensity)

Set the pixel density of the images the encoder will encode. If this method is not called, then a default pixel aspect ratio of 1x1 will be applied, and no DPI information will be stored in the image.

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pub fn encode( &mut self, image: &[u8], width: u32, height: u32, color_type: ColorType ) -> ImageResult<()>

Encodes the image stored in the raw byte buffer image that has dimensions width and height and ColorType c

The Image in encoded with subsampling ratio 4:2:2

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pub fn encode_image<I: GenericImageView>( &mut self, image: &I ) -> ImageResult<()>where I::Pixel: PixelWithColorType,

Encodes the given image.

As a special feature this does not require the whole image to be present in memory at the same time such that it may be computed on the fly, which is why this method exists on this encoder but not on others. Instead the encoder will iterate over 8-by-8 blocks of pixels at a time, inspecting each pixel exactly once. You can rely on this behaviour when calling this method.

The Image in encoded with subsampling ratio 4:2:2

Trait Implementations§

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impl<W: Write> ImageEncoder for JpegEncoder<W>

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fn write_image( self, buf: &[u8], width: u32, height: u32, color_type: ColorType ) -> ImageResult<()>

Writes all the bytes in an image to the encoder. Read more

Auto Trait Implementations§

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impl<W> RefUnwindSafe for JpegEncoder<W>where W: RefUnwindSafe,

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impl<W> Send for JpegEncoder<W>where W: Send,

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impl<W> Sync for JpegEncoder<W>where W: Sync,

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impl<W> Unpin for JpegEncoder<W>where W: Unpin,

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impl<W> UnwindSafe for JpegEncoder<W>where W: UnwindSafe,

Blanket Implementations§

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impl<T> Any for Twhere T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for Twhere T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for Twhere T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for Twhere U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> Pointable for T

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const ALIGN: usize = _

The alignment of pointer.
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type Init = T

The type for initializers.
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unsafe fn init(init: <T as Pointable>::Init) -> usize

Initializes a with the given initializer. Read more
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unsafe fn deref<'a>(ptr: usize) -> &'a T

Dereferences the given pointer. Read more
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unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

Mutably dereferences the given pointer. Read more
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unsafe fn drop(ptr: usize)

Drops the object pointed to by the given pointer. Read more
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impl<T, U> TryFrom<U> for Twhere U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.