Struct image::jpeg::JpegEncoder
source · [−]pub struct JpegEncoder<'a, W: 'a> { /* private fields */ }
Expand description
The representation of a JPEG encoder
Implementations
sourceimpl<'a, W: Write> JpegEncoder<'a, W>
impl<'a, W: Write> JpegEncoder<'a, W>
sourcepub fn new(w: &mut W) -> JpegEncoder<'_, W>
pub fn new(w: &mut W) -> JpegEncoder<'_, W>
Create a new encoder that writes its output to w
sourcepub fn new_with_quality(w: &mut W, quality: u8) -> JpegEncoder<'_, W>
pub fn new_with_quality(w: &mut 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.
sourcepub fn set_pixel_density(&mut self, pixel_density: PixelDensity)
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.
sourcepub fn encode(
&mut self,
image: &[u8],
width: u32,
height: u32,
color_type: ColorType
) -> ImageResult<()>
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
sourcepub fn encode_image<I: GenericImageView>(
&mut self,
image: &I
) -> ImageResult<()>
pub fn encode_image<I: GenericImageView>(
&mut self,
image: &I
) -> ImageResult<()>
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
sourceimpl<'a, W: Write> ImageEncoder for JpegEncoder<'a, W>
impl<'a, W: Write> ImageEncoder for JpegEncoder<'a, W>
Auto Trait Implementations
impl<'a, W> RefUnwindSafe for JpegEncoder<'a, W> where
W: RefUnwindSafe,
impl<'a, W> Send for JpegEncoder<'a, W> where
W: Send,
impl<'a, W> Sync for JpegEncoder<'a, W> where
W: Sync,
impl<'a, W> Unpin for JpegEncoder<'a, W>
impl<'a, W> !UnwindSafe for JpegEncoder<'a, W>
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcepub fn borrow_mut(&mut self) -> &mut T
pub fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more