Struct Ifd 

pub struct Ifd {
    pub index: Option<usize>,
    /* private fields */
}

A parsed Image File Directory (IFD).

Fields

index: Option<usize>

Index of this IFD in the top-level chain (0-based), or None when the IFD was reached directly through an explicit offset such as a SubIFD.

Implementations

impl Ifd

pub fn offset(&self) -> u64

File offset where this IFD starts.

pub fn tag(&self, code: u16) -> Option<&Tag>

Look up a tag by its code.

pub fn tags(&self) -> &[Tag]

Returns all tags in this IFD.

pub fn width(&self) -> u32

Image width in pixels.

pub fn height(&self) -> u32

Image height in pixels.

pub fn bits_per_sample(&self) -> Result<Vec<u16>>

Bits per sample for each channel, validating the tag encoding.

A missing tag defaults to 1 per the TIFF specification. SHORT values are used directly; BYTE and LONG values written by nonconforming writers are coerced when they fit. Any other tag type is rejected instead of silently falling back to the default.

pub fn compression(&self) -> u16

Compression scheme (1 = none, 5 = LZW, 8 = Deflate, …).

pub fn photometric_interpretation(&self) -> Option<u16>

Photometric interpretation.

pub fn photometric_interpretation_enum( &self, ) -> Option<PhotometricInterpretation>

Typed photometric interpretation, defaulting to MinIsBlack when the TIFF tag is omitted.

pub fn samples_per_pixel(&self) -> u16

Number of samples (bands) per pixel.

pub fn is_tiled(&self) -> bool

Returns true if this IFD uses tiled layout.

pub fn tile_width(&self) -> Option<u32>

Tile width (only for tiled IFDs).

pub fn tile_height(&self) -> Option<u32>

Tile height (only for tiled IFDs).

pub fn rows_per_strip(&self) -> u32

Rows per strip. Defaults to the image height when not present.

pub fn sample_format(&self) -> Result<Vec<u16>>

Sample format for each channel, validating the tag encoding.

A missing tag defaults to 1 (unsigned integer) per the TIFF specification. SHORT values are used directly; BYTE and LONG values written by nonconforming writers are coerced when they fit. Any other tag type is rejected instead of silently falling back to the default.

pub fn planar_configuration(&self) -> u16

Planar configuration. Defaults to chunky (1).

pub fn predictor(&self) -> u16

Predictor. Defaults to no predictor (1).

pub fn lerc_parameters(&self) -> Result<Option<LercParameters>>

TIFF-side LERC parameters, when present.

pub fn extra_samples(&self) -> Result<Vec<ExtraSample>>

TIFF ExtraSamples semantics.

pub fn color_map(&self) -> Result<Option<ColorMap>>

TIFF ColorMap values for palette images.

pub fn ink_set(&self) -> Result<Option<InkSet>>

TIFF InkSet semantics for separated photometric data.

pub fn ycbcr_subsampling(&self) -> Result<Option<[u16; 2]>>

TIFF YCbCr chroma subsampling factors.

pub fn ycbcr_positioning(&self) -> Result<Option<YCbCrPositioning>>

TIFF YCbCr sample positioning.

pub fn reference_black_white(&self) -> Result<Option<[f64; 6]>>

TIFF ReferenceBlackWhite values normalized to f64.

pub fn color_model(&self) -> Result<ColorModel>

Structured color-model metadata synthesized from TIFF photometric and ancillary color tags.

pub fn strip_offsets(&self) -> Option<Vec<u64>>

Strip offsets as normalized u64s.

pub fn strip_byte_counts(&self) -> Option<Vec<u64>>

Strip byte counts as normalized u64s.

pub fn tile_offsets(&self) -> Option<Vec<u64>>

Tile offsets as normalized u64s.

pub fn tile_byte_counts(&self) -> Option<Vec<u64>>

Tile byte counts as normalized u64s.

pub fn sub_ifd_offsets(&self) -> Option<Vec<u64>>

SubIFD offsets as normalized u64s.

pub fn raster_layout(&self) -> Result<RasterLayout>

Normalize and validate the raster layout for typed reads.

pub fn decoded_raster_layout(&self) -> Result<RasterLayout>

Normalize the raster layout produced by high-level pixel reads.

This layout reflects color-decoded output rather than the on-disk sample organization. For example, palette and YCbCr rasters decode to RGB pixels, and sub-byte integer rasters expand to 8-bit samples.

Trait Implementations

impl Clone for Ifd

fn clone(&self) -> Ifd

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Ifd

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

Formats the value using the given formatter.