Struct SubImage

pub struct SubImage<I> { /* private fields */ }

A View into another image

Instances of this struct can be created using:

• GenericImage::sub_image to create a mutable view,
• GenericImageView::view to create an immutable view,
• SubImage::new to instantiate the struct directly.

Note that this does not implement GenericImage, but it dereferences to one which allows you to use it as if it did. See Design Considerations below for details.

Design Considerations

For reasons relating to coherence, this is not itself a GenericImage or a GenericImageView. In short, we want to reserve the ability of adding traits implemented for all generic images but in a different manner for SubImage. This may be required to ensure that stacking sub-images comes at no double indirect cost.

If, ultimately, this is not needed then a directly implementation of GenericImage can and will get added. This inconvenience may alternatively get resolved if Rust allows some forms of specialization, which might make this trick unnecessary and thus also allows for a direct implementation.

Implementations

impl<I> SubImage<I>

pub fn new(image: I, x: u32, y: u32, width: u32, height: u32) -> SubImage<I>

Construct a new subimage The coordinates set the position of the top left corner of the SubImage.

pub fn change_bounds(&mut self, x: u32, y: u32, width: u32, height: u32)

Change the coordinates of this subimage.

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

The offsets of this subimage relative to the underlying image.

pub fn to_image( &self, ) -> ImageBuffer<<<I as Deref>::Target as GenericImageView>::Pixel, Vec<<<<I as Deref>::Target as GenericImageView>::Pixel as Pixel>::Subpixel>>

where I: Deref, I::Target: GenericImageView + 'static,

Convert this subimage to an ImageBuffer

impl<I> SubImage<I>

where I: Deref, I::Target: GenericImageView,

Methods for readable images.

pub fn view( &self, x: u32, y: u32, width: u32, height: u32, ) -> SubImage<&I::Target>

Create a sub-view of the image.

The coordinates given are relative to the current view on the underlying image.

Note that this method is preferred to the one from GenericImageView. This is accessible with the explicit method call syntax but it should rarely be needed due to causing an extra level of indirection.

use image::{GenericImageView, RgbImage, SubImage};
let buffer = RgbImage::new(10, 10);

let subimage: SubImage<&RgbImage> = buffer.view(0, 0, 10, 10);
let subview: SubImage<&RgbImage> = subimage.view(0, 0, 10, 10);

// Less efficient and NOT &RgbImage
let _: SubImage<&_> = GenericImageView::view(&*subimage, 0, 0, 10, 10);

pub fn inner(&self) -> &I::Target

Get a reference to the underlying image.

impl<I> SubImage<I>

where I: DerefMut, I::Target: GenericImage,

pub fn sub_image( &mut self, x: u32, y: u32, width: u32, height: u32, ) -> SubImage<&mut I::Target>

Create a mutable sub-view of the image.

The coordinates given are relative to the current view on the underlying image.

pub fn inner_mut(&mut self) -> &mut I::Target

Get a mutable reference to the underlying image.

Trait Implementations

impl<I: Clone> Clone for SubImage<I>

fn clone(&self) -> SubImage<I>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<I> Deref for SubImage<I>

where I: Deref,

type Target = SubImageInner<I>

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<I> DerefMut for SubImage<I>

where I: DerefMut,

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

Mutably dereferences the value.

impl<I: Copy> Copy for SubImage<I>