Struct TransformOptions 

#[non_exhaustive]
pub struct TransformOptions {

    pub width: Option<u32>,
    pub height: Option<u32>,
    pub fit: Option<Fit>,
    pub position: Option<Position>,
    pub format: Option<MediaType>,
    pub quality: Option<u8>,
    pub optimize: OptimizeMode,
    pub target_quality: Option<TargetQuality>,
    pub background: Option<Rgba8>,
    pub rotate: Rotation,
    pub auto_orient: bool,
    pub strip_metadata: bool,
    pub preserve_exif: bool,
    pub blur: Option<f32>,
    pub sharpen: Option<f32>,
    pub grayscale: bool,
    pub without_enlargement: bool,
    pub crop: Option<CropRegion>,
    pub deadline: Option<Duration>,
}

Raw transform options before defaulting and validation has completed.

Start from TransformOptions::default() and assign the fields you need. Validation and the resolution of the rest happen inside transform, which reports what it refuses through TransformError. The struct is #[non_exhaustive], so a field a later version of truss adds is a minor change rather than a breaking one, and a struct literal is not available from outside the crate.

Examples

use truss::{TransformOptions, MediaType, Rotation};

let mut opts = TransformOptions::default();
opts.width = Some(800);
opts.height = Some(600);
opts.format = Some(MediaType::Webp);
opts.quality = Some(80);
opts.rotate = Rotation::DEG_90;
assert_eq!(opts.width, Some(800));
assert_eq!(opts.quality, Some(80));
assert_eq!(opts.rotate, Rotation::DEG_90);
// strip_metadata defaults to true
assert!(opts.strip_metadata);

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.

width: Option<u32>

The desired output width in pixels.

height: Option<u32>

The desired output height in pixels.

fit: Option<Fit>

The requested resize fit mode.

position: Option<Position>

The requested positioning mode.

format: Option<MediaType>

The requested output format.

quality: Option<u8>

The requested lossy quality.

optimize: OptimizeMode

The requested optimization mode.

target_quality: Option<TargetQuality>

Optional perceptual target used by lossy optimization.

background: Option<Rgba8>

The requested background color.

rotate: Rotation

The requested extra rotation.

auto_orient: bool

Whether EXIF-based auto-orientation should run.

strip_metadata: bool

Whether metadata should be stripped from the output.

preserve_exif: bool

Whether EXIF metadata should be preserved.

blur: Option<f32>

Gaussian blur sigma.

When set, a Gaussian blur with the given sigma is applied after resizing and before encoding. Valid range is 0.1–100.0.

sharpen: Option<f32>

Unsharp-mask (sharpen) sigma.

When set, an unsharp mask with the given sigma is applied after resizing and before encoding. Valid range is 0.1–100.0. The sharpening threshold is fixed at 1.

grayscale: bool

Whether the image should be desaturated to grayscale.

When true, the image is converted to grayscale after resizing, blur, and sharpening, and before any watermark is composited, so a watermark keeps its own colors. Luminance is computed with the Rec. 601 weights the image crate uses, and the alpha channel is preserved.

without_enlargement: bool

Whether a source smaller than the requested size may be scaled up.

When true, the resize never enlarges: an image already within the requested bounds is left at its own size. This is a separate question from Fit, which decides how the image is arranged relative to the box, so the two combine freely. contain still pads out to the full requested box; only the content inside it stops growing.

crop: Option<CropRegion>

Optional explicit crop region applied before resize.

When set, the image is cropped to the specified rectangle before any resize operation. The crop region is validated at runtime against the decoded image dimensions.

deadline: Option<Duration>

Optional wall-clock deadline for the transform pipeline.

When set, the transform checks elapsed time at each pipeline stage and returns TransformError::LimitExceeded if the deadline is exceeded. Adapters inject this value based on their operational requirements — for example, the HTTP server sets a 30-second deadline while the CLI leaves it as None (unlimited).

The check happens between stages, not inside one. A stage that is already running runs to its end, so a transform can return after the deadline rather than at it, by however long its slowest single step takes. Encoding is the step where that matters, since no encoder truss calls can be interrupted part way.

Trait Implementations

impl Clone for TransformOptions

fn clone(&self) -> TransformOptions

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TransformOptions

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

Formats the value using the given formatter.

impl Default for TransformOptions

fn default() -> Self

Returns the “default value” for a type.

impl PartialEq for TransformOptions

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for TransformOptions