Struct image::ImageBuffer

pub struct ImageBuffer<P: Pixel, Container> { /* fields omitted */ }

Generic image buffer

This is an image parameterised by its Pixel types, represented by a width and height and a container of channel data. It provides direct access to its pixels and implements the GenericImageView and GenericImage traits. In many ways, this is the standard buffer implementing those traits. Using this concrete type instead of a generic type parameter has been shown to improve performance.

The crate defines a few type aliases with regularly used pixel types for your convenience, such as RgbImage, GrayImage etc.

To convert between images of different Pixel types use DynamicImage.

You can retrieve a complete description of the buffer’s layout and contents through as_flat_samples and as_flat_samples_mut. This can be handy to also use the contents in a foreign language, map it as a GPU host buffer or other similar tasks.

Examples

Create a simple canvas and paint a small cross.

use image::{RgbImage, Rgb};

let mut img = RgbImage::new(32, 32);

for x in 15..=17 {
    for y in 8..24 {
        img.put_pixel(x, y, Rgb([255, 0, 0]));
        img.put_pixel(y, x, Rgb([255, 0, 0]));
    }
}

Overlays an image on top of a larger background raster.

use image::{GenericImage, GenericImageView, ImageBuffer, open};

let on_top = open("path/to/some.png").unwrap().into_rgb();
let mut img = ImageBuffer::from_fn(512, 512, |x, y| {
    if (x + y) % 2 == 0 {
        image::Rgb([0, 0, 0])
    } else {
        image::Rgb([255, 255, 255])
    }
});

image::imageops::overlay(&mut img, &on_top, 128, 128);

Convert an RgbaImage to a GrayImage.

use image::{open, DynamicImage};

let rgba = open("path/to/some.png").unwrap().into_rgba();
let gray = DynamicImage::ImageRgba8(rgba).into_luma();

Implementations

impl<P, Container> ImageBuffer<P, Container> where
    P: Pixel + 'static,
    P::Subpixel: 'static,
    Container: Deref<Target = [P::Subpixel]>, 

pub fn from_raw(
    width: u32,
    height: u32,
    buf: Container
) -> Option<ImageBuffer<P, Container>>

Contructs a buffer from a generic container (for example a Vec or a slice)

Returns None if the container is not big enough (including when the image dimensions necessitate an allocation of more bytes than supported by the container).

pub fn into_raw(self) -> Container

Returns the underlying raw buffer

pub fn as_raw(&self) -> &Container

Returns the underlying raw buffer

pub fn dimensions(&self) -> (u32, u32)

The width and height of this image.

pub fn width(&self) -> u32

The width of this image.

pub fn height(&self) -> u32

The height of this image.

pub fn pixels(&self) -> Pixels<'_, P>

Returns an iterator over the pixels of this image. The iteration order is x = 0 to width then y = 0 to height

pub fn rows(&self) -> Rows<'_, P>

Returns an iterator over the rows of this image.

Only non-empty rows can be iterated in this manner. In particular the iterator will not yield any item when the width of the image is 0 or a pixel type without any channels is used. This ensures that its length can always be represented by usize.

pub fn enumerate_pixels(&self) -> EnumeratePixels<'_, P>

Enumerates over the pixels of the image. The iterator yields the coordinates of each pixel along with a reference to them. The iteration order is x = 0 to width then y = 0 to height Starting from the top left.

pub fn enumerate_rows(&self) -> EnumerateRows<'_, P>

Enumerates over the rows of the image. The iterator yields the y-coordinate of each row along with a reference to them.

pub fn get_pixel(&self, x: u32, y: u32) -> &P

Gets a reference to the pixel at location (x, y)

Panics

Panics if (x, y) is out of the bounds (width, height).

pub fn sample_layout(&self) -> SampleLayout

Get the format of the buffer when viewed as a matrix of samples.

pub fn into_flat_samples(self) -> FlatSamples<Container> where
    Container: AsRef<[P::Subpixel]>, 

Return the raw sample buffer with its stride an dimension information.

The returned buffer is guaranteed to be well formed in all cases. It is layed out by colors, width then height, meaning channel_stride <= width_stride <= height_stride. All strides are in numbers of elements but those are mostly u8 in which case the strides are also byte strides.

pub fn as_flat_samples(&self) -> FlatSamples<&[P::Subpixel]> where
    Container: AsRef<[P::Subpixel]>, 

Return a view on the raw sample buffer.

See into_flat_samples for more details.

pub fn as_flat_samples_mut(&mut self) -> FlatSamples<&mut [P::Subpixel]> where
    Container: AsMut<[P::Subpixel]>, 

Return a mutable view on the raw sample buffer.

See into_flat_samples for more details.

impl<P, Container> ImageBuffer<P, Container> where
    P: Pixel + 'static,
    P::Subpixel: 'static,
    Container: Deref<Target = [P::Subpixel]> + DerefMut, 

pub fn pixels_mut(&mut self) -> PixelsMut<'_, P>

Returns an iterator over the mutable pixels of this image.

pub fn rows_mut(&mut self) -> RowsMut<'_, P>

Returns an iterator over the mutable rows of this image.

Only non-empty rows can be iterated in this manner. In particular the iterator will not yield any item when the width of the image is 0 or a pixel type without any channels is used. This ensures that its length can always be represented by usize.

pub fn enumerate_pixels_mut(&mut self) -> EnumeratePixelsMut<'_, P>

Enumerates over the pixels of the image. The iterator yields the coordinates of each pixel along with a mutable reference to them.

pub fn enumerate_rows_mut(&mut self) -> EnumerateRowsMut<'_, P>

Enumerates over the rows of the image. The iterator yields the y-coordinate of each row along with a mutable reference to them.

pub fn get_pixel_mut(&mut self, x: u32, y: u32) -> &mut P

Gets a reference to the mutable pixel at location (x, y)

Panics

Panics if (x, y) is out of the bounds (width, height).

pub fn put_pixel(&mut self, x: u32, y: u32, pixel: P)

Puts a pixel at location (x, y)

Panics

Panics if (x, y) is out of the bounds (width, height).

impl<P, Container> ImageBuffer<P, Container> where
    P: Pixel + 'static,
    [P::Subpixel]: EncodableLayout,
    Container: Deref<Target = [P::Subpixel]>, 

pub fn save<Q>(&self, path: Q) -> ImageResult<()> where
    Q: AsRef<Path>, 

Saves the buffer to a file at the path specified.

The image format is derived from the file extension. Currently only jpeg and png files are supported.

impl<P, Container> ImageBuffer<P, Container> where
    P: Pixel + 'static,
    [P::Subpixel]: EncodableLayout,
    Container: Deref<Target = [P::Subpixel]>, 

pub fn save_with_format<Q>(
    &self,
    path: Q,
    format: ImageFormat
) -> ImageResult<()> where
    Q: AsRef<Path>, 

Saves the buffer to a file at the specified path in the specified format.

See save_buffer_with_format for supported types.

impl<P: Pixel + 'static> ImageBuffer<P, Vec<P::Subpixel>> where
    P::Subpixel: 'static, 

pub fn new(width: u32, height: u32) -> ImageBuffer<P, Vec<P::Subpixel>>

Creates a new image buffer based on a Vec<P::Subpixel>.

Panics

Panics when the resulting image is larger the the maximum size of a vector.

pub fn from_pixel(
    width: u32,
    height: u32,
    pixel: P
) -> ImageBuffer<P, Vec<P::Subpixel>>

Constructs a new ImageBuffer by copying a pixel

Panics

Panics when the resulting image is larger the the maximum size of a vector.

pub fn from_fn<F>(
    width: u32,
    height: u32,
    f: F
) -> ImageBuffer<P, Vec<P::Subpixel>> where
    F: FnMut(u32, u32) -> P, 

Constructs a new ImageBuffer by repeated application of the supplied function.

The arguments to the function are the pixel’s x and y coordinates.

Panics

Panics when the resulting image is larger the the maximum size of a vector.

pub fn from_vec(
    width: u32,
    height: u32,
    buf: Vec<P::Subpixel>
) -> Option<ImageBuffer<P, Vec<P::Subpixel>>>

Creates an image buffer out of an existing buffer. Returns None if the buffer is not big enough.

pub fn into_vec(self) -> Vec<P::Subpixel>

Consumes the image buffer and returns the underlying data as an owned buffer

impl ImageBuffer<Luma<u8>, Vec<u8, Global>>

pub fn expand_palette(
    self,
    palette: &[(u8, u8, u8)],
    transparent_idx: Option<u8>
) -> RgbaImage

Expands a color palette by re-using the existing buffer. Assumes 8 bit per pixel. Uses an optionally transparent index to adjust it’s alpha value accordingly.

Trait Implementations

impl<P, Container> Clone for ImageBuffer<P, Container> where
    P: Pixel,
    Container: Deref<Target = [P::Subpixel]> + Clone, 

fn clone(&self) -> ImageBuffer<P, Container>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a, 'b, Container, FromType: Pixel + 'static, ToType: Pixel + 'static> ConvertBuffer<ImageBuffer<ToType, Vec<<ToType as Pixel>::Subpixel, Global>>> for ImageBuffer<FromType, Container> where
    Container: Deref<Target = [FromType::Subpixel]>,
    ToType: FromColor<FromType>,
    FromType::Subpixel: 'static,
    ToType::Subpixel: 'static, 

fn convert(&self) -> ImageBuffer<ToType, Vec<ToType::Subpixel>>

Examples

Convert RGB image to gray image.

use image::buffer::ConvertBuffer;
use image::GrayImage;
 
let image_path = "examples/fractal.png";
let image = image::open(&image_path)
    .expect("Open file failed")
    .to_rgba();
 
let gray_image: GrayImage = image.convert();

impl<P: Debug + Pixel, Container: Debug> Debug for ImageBuffer<P, Container>

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

Formats the value using the given formatter.

impl<P, Container> Default for ImageBuffer<P, Container> where
    P: Pixel,
    Container: Default, 

fn default() -> Self

Returns the “default value” for a type.

impl<P, Container> Deref for ImageBuffer<P, Container> where
    P: Pixel + 'static,
    P::Subpixel: 'static,
    Container: Deref<Target = [P::Subpixel]>, 

type Target = [P::Subpixel]

The resulting type after dereferencing.

fn deref(&self) -> &<Self as Deref>::Target

Dereferences the value.

impl<P, Container> DerefMut for ImageBuffer<P, Container> where
    P: Pixel + 'static,
    P::Subpixel: 'static,
    Container: Deref<Target = [P::Subpixel]> + DerefMut, 

fn deref_mut(&mut self) -> &mut <Self as Deref>::Target

Mutably dereferences the value.

impl<P, Container> GenericImage for ImageBuffer<P, Container> where
    P: Pixel + 'static,
    Container: Deref<Target = [P::Subpixel]> + DerefMut,
    P::Subpixel: 'static, 

unsafe fn unsafe_put_pixel(&mut self, x: u32, y: u32, pixel: P)

Puts a pixel at location (x, y), ignoring bounds checking.

fn blend_pixel(&mut self, x: u32, y: u32, p: P)

Put a pixel at location (x, y), taking into account alpha channels

DEPRECATED: This method will be removed. Blend the pixel directly instead.

type InnerImage = Self

Underlying image type. This is mainly used by SubImages in order to always have a reference to the original image. This allows for less indirections and it eases the use of nested SubImages.

fn get_pixel_mut(&mut self, x: u32, y: u32) -> &mut P

Gets a reference to the mutable pixel at location (x, y). Indexed from top left.

fn put_pixel(&mut self, x: u32, y: u32, pixel: P)

Put a pixel at location (x, y). Indexed from top left.

fn copy_within(&mut self, source: Rect, x: u32, y: u32) -> bool

Copies all of the pixels from one part of this image to another part of this image.

fn inner_mut(&mut self) -> &mut Self::InnerImage

Returns a mutable reference to the underlying image.

fn copy_from<O>(&mut self, other: &O, x: u32, y: u32) -> ImageResult<()> where
    O: GenericImageView<Pixel = Self::Pixel>, 

Copies all of the pixels from another image into this image.

fn sub_image(
    &mut self,
    x: u32,
    y: u32,
    width: u32,
    height: u32
) -> SubImage<&mut Self::InnerImage>

Returns a mutable subimage that is a view into this image. If you want an immutable subimage instead, use GenericImageView::view The coordinates set the position of the top left corner of the SubImage.

impl<P, Container> GenericImageView for ImageBuffer<P, Container> where
    P: Pixel + 'static,
    Container: Deref<Target = [P::Subpixel]> + Deref,
    P::Subpixel: 'static, 

unsafe fn unsafe_get_pixel(&self, x: u32, y: u32) -> P

Returns the pixel located at (x, y), ignoring bounds checking.

type Pixel = P

The type of pixel.

type InnerImageView = Self

Underlying image type. This is mainly used by SubImages in order to always have a reference to the original image. This allows for less indirections and it eases the use of nested SubImages.

fn dimensions(&self) -> (u32, u32)

The width and height of this image.

fn bounds(&self) -> (u32, u32, u32, u32)

The bounding rectangle of this image.

fn get_pixel(&self, x: u32, y: u32) -> P

Returns the pixel located at (x, y). Indexed from top left.

fn inner(&self) -> &Self::InnerImageView

Returns a reference to the underlying image.

fn width(&self) -> u32

The width of this image.

fn height(&self) -> u32

The height of this image.

fn in_bounds(&self, x: u32, y: u32) -> bool

Returns true if this x, y coordinate is contained inside the image.

fn pixels(&self) -> Pixels<'_, Self>

Returns an Iterator over the pixels of this image. The iterator yields the coordinates of each pixel along with their value

fn view(
    &self,
    x: u32,
    y: u32,
    width: u32,
    height: u32
) -> SubImage<&Self::InnerImageView>

Returns an subimage that is an immutable view into this image. You can use GenericImage::sub_image if you need a mutable view instead. The coordinates set the position of the top left corner of the view.

impl<P: Hash + Pixel, Container: Hash> Hash for ImageBuffer<P, Container>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl<P, Container> Index<(u32, u32)> for ImageBuffer<P, Container> where
    P: Pixel + 'static,
    P::Subpixel: 'static,
    Container: Deref<Target = [P::Subpixel]>, 

type Output = P

The returned type after indexing.

fn index(&self, (x, y): (u32, u32)) -> &P

Performs the indexing (container[index]) operation.

impl<P, Container> IndexMut<(u32, u32)> for ImageBuffer<P, Container> where
    P: Pixel + 'static,
    P::Subpixel: 'static,
    Container: Deref<Target = [P::Subpixel]> + DerefMut, 

fn index_mut(&mut self, (x, y): (u32, u32)) -> &mut P

Performs the mutable indexing (container[index]) operation.

impl<P: PartialEq + Pixel, Container: PartialEq> PartialEq<ImageBuffer<P, Container>> for ImageBuffer<P, Container>

fn eq(&self, other: &ImageBuffer<P, Container>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &ImageBuffer<P, Container>) -> bool

This method tests for !=.

impl<P: Eq + Pixel, Container: Eq> Eq for ImageBuffer<P, Container>

impl<P: Pixel, Container> StructuralEq for ImageBuffer<P, Container>

impl<P: Pixel, Container> StructuralPartialEq for ImageBuffer<P, Container>