Trait image::ImageDecoderExt

pub trait ImageDecoderExt<'a>: ImageDecoder<'a> + Sized {
    fn read_rect_with_progress<F: Fn(Progress)>(
        &mut self,
        x: u32,
        y: u32,
        width: u32,
        height: u32,
        buf: &mut [u8],
        progress_callback: F
    ) -> ImageResult<()>;

    fn read_rect(
        &mut self,
        x: u32,
        y: u32,
        width: u32,
        height: u32,
        buf: &mut [u8]
    ) -> ImageResult<()> { ... }
}

Specialized image decoding not be supported by all formats

Required Methods

fn read_rect_with_progress<F: Fn(Progress)>(
    &mut self,
    x: u32,
    y: u32,
    width: u32,
    height: u32,
    buf: &mut [u8],
    progress_callback: F
) -> ImageResult<()>

Decode a rectangular section of the image, periodically reporting progress.

The output buffer will be filled with fields specified by ImageDecoder::color_type(), in that order, each field represented in native-endian.

The progress callback will be called at least once at the start and the end of decoding, implementations are encouraged to call this more often, with a frequency meaningful for display to the end-user.

This function will panic if the output buffer isn’t at least color_type().bytes_per_pixel() * color_type().channel_count() * width * height bytes long.

Provided Methods

fn read_rect(
    &mut self,
    x: u32,
    y: u32,
    width: u32,
    height: u32,
    buf: &mut [u8]
) -> ImageResult<()>

Decode a rectangular section of the image; see read_rect_with_progress().

Implementors