Struct EncodeOptions 

#[non_exhaustive]
pub struct EncodeOptions {

    pub quality: u8,
    pub lossless: bool,
    pub effort: Option<u8>,
    pub compression_level: Option<u8>,
    pub palette: bool,
    pub colours: Option<u16>,
    pub dither: Option<f32>,
    pub alpha_quality: u8,
    pub near_lossless: bool,
    pub chroma_subsampling: Option<ChromaSubsampling>,
    pub keep_exif: bool,
    pub keep_xmp: bool,
    pub progressive: bool,
}

Encoder tuning shared across formats.

Fields that a format has no notion of are ignored by that format rather than rejected, so the same options value can be handed to any encoder. Every field’s default leaves a format’s output as it was before the field existed.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

quality: u8

Lossy quality, 1–100. Ignored by lossless formats, and by a format with both modes when lossless is set.

lossless: bool

For a format that has both a lossy and a lossless mode (WebP), choose lossless. Off by default: such a format encodes lossy at quality, as cwebp and sharp do. Formats with one mode ignore it.

effort: Option<u8>

CPU spent for a smaller file, 0 (fastest) to 10, in each format’s own range as sharp defines it: WebP 0–6 and AVIF 0–9, both with a default of 4. None is the format’s default.

compression_level: Option<u8>

PNG’s DEFLATE level, 0 (store) to 9. None derives it from quality, as before this option existed.

palette: bool

Write PNG as a palette image of at most colours entries (sharp’s palette). Setting colours or dither implies it, as in sharp.

colours: Option<u16>

The palette size for palette PNG and GIF, 2–256. None is 256 for PNG, and for GIF the size quality implies.

dither: Option<f32>

How much of the quantization error a palette image diffuses, 0 (none) to 1 (full Floyd-Steinberg, the default). None is 1.

alpha_quality: u8

Quality of lossy WebP’s alpha channel, 0–100; 100, the default, keeps it lossless.

near_lossless: bool

Lossless WebP that may change pixels a little where it saves bytes, by as much as quality allows (sharp’s nearLossless; 100 changes nothing). Implies lossless.

chroma_subsampling: Option<ChromaSubsampling>

Chroma sampling for JPEG and AVIF. None is each format’s default: for JPEG 4:2:0 below quality 90 and 4:4:4 from it, for AVIF 4:2:0.

keep_exif: bool

Copy the source’s EXIF block into the output (sharp’s keepExif), where the format has a place for one: JPEG, PNG, WebP and AVIF. Off by default, which strips camera data and location from uploads.

keep_xmp: bool

Copy the source’s XMP packet into the output (sharp’s keepXmp), where the format has a place for one: JPEG, PNG, WebP, TIFF, AVIF and JPEG XL. Off by default, as for EXIF.

progressive: bool

Write JPEG as progressive (sharp’s progressive): a coarse picture first, sharpened by later scans, and usually a little smaller. The encoder then holds the image’s coefficients rather than streaming.

Implementations

impl EncodeOptions

pub const DEFAULT_QUALITY: u8 = 80

The default quality used when none is given.

pub fn with_quality(quality: u8) -> Result<EncodeOptions, PixelsError>

Options with the given quality.

Errors

Returns PixelsError::InvalidArgument unless quality is in 1..=100.

pub const fn with_lossless(self, lossless: bool) -> EncodeOptions

These options with lossless replaced.

pub fn with_effort(self, effort: u8) -> Result<EncodeOptions, PixelsError>

These options with an encoding effort, 0..=10 (see EncodeOptions::effort). A value past a format’s own range is clamped to it.

Errors

Returns PixelsError::InvalidArgument above 10.

pub fn with_compression_level( self, level: u8, ) -> Result<EncodeOptions, PixelsError>

These options with a PNG DEFLATE level, 0..=9.

Errors

Returns PixelsError::InvalidArgument above 9.

pub const fn with_palette(self, palette: bool) -> EncodeOptions

These options with palette PNG on or off.

pub fn with_colours(self, colours: u16) -> Result<EncodeOptions, PixelsError>

These options with a palette size, 2..=256, which for PNG implies a palette.

Errors

Returns PixelsError::InvalidArgument outside 2..=256.

pub fn with_dither(self, dither: f32) -> Result<EncodeOptions, PixelsError>

These options with a dithering level, 0..=1, which for PNG implies a palette.

Errors

Returns PixelsError::InvalidArgument outside 0..=1.

pub fn with_alpha_quality( self, quality: u8, ) -> Result<EncodeOptions, PixelsError>

These options with a lossy WebP alpha quality, 0..=100.

Errors

Returns PixelsError::InvalidArgument above 100.

pub const fn with_near_lossless(self, near_lossless: bool) -> EncodeOptions

These options with near-lossless WebP on or off.

pub const fn with_chroma_subsampling( self, subsampling: ChromaSubsampling, ) -> EncodeOptions

These options with an explicit chroma subsampling.

pub const fn with_keep_exif(self, keep: bool) -> EncodeOptions

These options keeping the source’s EXIF, or not.

pub const fn with_keep_xmp(self, keep: bool) -> EncodeOptions

These options with keep_xmp replaced.

pub const fn with_keep_metadata(self, keep: bool) -> EncodeOptions

These options keeping EXIF and XMP both (sharp’s keepMetadata; the ICC profile is always kept).

pub const fn with_progressive(self, progressive: bool) -> EncodeOptions

These options with progressive JPEG on or off.

pub const fn wants_palette(&self) -> bool

Whether a PNG should be written as a palette image.

Trait Implementations

impl Clone for EncodeOptions

fn clone(&self) -> EncodeOptions

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for EncodeOptions

impl Debug for EncodeOptions

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

Formats the value using the given formatter.

impl Default for EncodeOptions

fn default() -> EncodeOptions

Returns the “default value” for a type.

impl PartialEq for EncodeOptions

fn eq(&self, other: &EncodeOptions) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for EncodeOptions