Struct JxlImage

pub struct JxlImage { /* private fields */ }

JPEG XL image.

Implementations

impl JxlImage

Constructors and data-feeding methods

pub fn builder() -> JxlImageBuilder

Creates a decoder builder with default options.

pub fn read_with_defaults(reader: impl Read) -> Result<JxlImage>

Reads an image from the reader with default options.

pub fn open_with_defaults(path: impl AsRef<Path>) -> Result<JxlImage>

Opens an image in the filesystem with default options.

pub fn feed_bytes(&mut self, buf: &[u8]) -> Result<usize>

Feeds more data into the decoder.

Returns total consumed bytes from the buffer.

pub fn finalize(&mut self) -> Result<()>

Signals the end of bitstream.

This is automatically done if open() or read() is used to decode the image.

impl JxlImage

Image and decoder metadata accessors

pub fn image_header(&self) -> &ImageHeader

Returns the image header.

pub fn width(&self) -> u32

Returns the image width with orientation applied.

pub fn height(&self) -> u32

Returns the image height with orientation applied.

pub fn original_icc(&self) -> Option<&[u8]>

Returns the original ICC profile embedded in the image.

pub fn rendered_icc(&self) -> Vec<u8>

Returns the ICC profile that describes rendered images.

The returned profile will change if different color encoding is specified using request_icc or request_color_encoding.

pub fn rendered_cicp(&self) -> Option<[u8; 4]>

Returns the CICP tag of the color encoding of rendered images, if there’s any.

pub fn pixel_format(&self) -> PixelFormat

Returns the pixel format of the rendered image.

pub fn hdr_type(&self) -> Option<HdrType>

Returns what HDR transfer function the image uses, if there’s any.

Returns None if the image is not HDR one.

pub fn render_spot_color(&self) -> bool

Returns whether the spot color channels will be rendered.

pub fn set_render_spot_color(&mut self, render_spot_color: bool) -> &mut Self

Sets whether the spot colour channels will be rendered.

pub fn aux_boxes(&self) -> &AuxBoxList

Returns the list of auxiliary boxes in the JPEG XL container.

The list may contain Exif and XMP metadata.

pub fn num_loaded_keyframes(&self) -> usize

Returns the number of currently loaded keyframes.

pub fn num_loaded_frames(&self) -> usize

Returns the number of currently loaded frames, including frames that are not displayed directly.

pub fn is_loading_done(&self) -> bool

Returns whether the image is loaded completely, without missing animation keyframes or partially loaded frames.

pub fn frame_by_keyframe(&self, keyframe_index: usize) -> Option<&IndexedFrame>

Returns frame data by keyframe index.

pub fn frame_header(&self, keyframe_index: usize) -> Option<&FrameHeader>

Returns the frame header for the given keyframe index, or None if the keyframe does not exist.

pub fn frame(&self, frame_idx: usize) -> Option<&IndexedFrame>

Returns frame data by frame index, including frames that are not displayed directly.

There are some situations where a frame is not displayed directly:

• It may be marked as reference only, and meant to be only used by other frames.
• It may contain LF image (which is 8x downsampled version) of another VarDCT frame.
• Zero duration frame that is not the last frame of image is blended with following frames and displayed together.

pub fn frame_offset(&self, frame_index: usize) -> Option<usize>

Returns the offset of frame within codestream, in bytes.

pub fn pool(&self) -> &JxlThreadPool

Returns the thread pool used by the renderer.

pub fn reader(&self) -> &ContainerDetectingReader

Returns the internal reader.

impl JxlImage

Color management methods

pub fn set_cms( &mut self, cms: impl ColorManagementSystem + Send + Sync + 'static, )

Sets color management system implementation to be used by the renderer.

pub fn request_icc(&mut self, icc_profile: &[u8]) -> Result<()>

Requests the decoder to render in specific color encoding, described by an ICC profile.

Errors

This function will return an error if it cannot parse the ICC profile.

pub fn request_color_encoding(&mut self, color_encoding: EnumColourEncoding)

Requests the decoder to render in specific color encoding, described by EnumColourEncoding.

impl JxlImage

Rendering to image buffers

pub fn render_frame(&self, keyframe_index: usize) -> Result<Render>

Renders the given keyframe.

pub fn render_frame_cropped(&self, keyframe_index: usize) -> Result<Render>

Renders the given keyframe with optional cropping region.

pub fn render_loading_frame(&mut self) -> Result<Render>

Renders the currently loading keyframe.

pub fn render_loading_frame_cropped(&mut self) -> Result<Render>

Renders the currently loading keyframe with optional cropping region.

pub fn set_image_region(&mut self, region: CropInfo) -> &mut Self

Sets the cropping region (region of interest).

Subsequent rendering methods will crop the image buffer according to the region.

impl JxlImage

JPEG bitstream reconstruction

pub fn jpeg_reconstruction_status(&self) -> JpegReconstructionStatus

Returns availability and validity of JPEG bitstream reconstruction data.

pub fn reconstruct_jpeg(&self, jpeg_output: impl Write) -> Result<()>

Reconstructs JPEG bitstream and writes the image to writer.

Errors

Returns an error if the reconstruction data is not available, incomplete or invalid, or if there was an error writing the image.

Note that reconstruction may fail even if jpeg_reconstruction_status returned Available.

Trait Implementations

impl Debug for JxlImage

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

Formats the value using the given formatter.