libimagequant/src/attr.rs at main · ImageOptim/libimagequant · GitHub

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use crate::error::Error;

use crate::hist::Histogram;

use crate::image::Image;

use crate::pal::{PalLen, MAX_COLORS, RGBA};

use crate::quant::{mse_to_quality, quality_to_mse, QuantizationResult};

use crate::remap::DitherMapMode;

use std::sync::Arc;

#[cfg(all(not(feature = "std"), feature = "no_std"))]

use crate::no_std_compat::*;

/// Starting point and settings for the quantization process

#[derive(Clone)]

#[cfg_attr(all(feature = "std", feature = "no_std"), deprecated(note = "Cargo features configuration issue: both std and no_std features are enabled in imagequant\nYou must disable default features to use no_std."))]

pub struct Attributes {

pub(crate) max_colors: PalLen,

target_mse: f64,

max_mse: Option<f64>,

kmeans_iteration_limit: f64,

kmeans_iterations: u16,

feedback_loop_trials: u16,

pub(crate) max_histogram_entries: u32,

min_posterization_output: u8,

min_posterization_input: u8,

pub(crate) last_index_transparent: bool,

pub(crate) use_contrast_maps: bool,

pub(crate) single_threaded_dithering: bool,

pub(crate) use_dither_map: DitherMapMode,

speed: u8,

pub(crate) progress_stage1: u8,

pub(crate) progress_stage2: u8,

pub(crate) progress_stage3: u8,

progress_callback: Option<Arc<dyn Fn(f32) -> ControlFlow + Send + Sync>>,

log_callback: Option<Arc<dyn Fn(&Attributes, &str) + Send + Sync>>,

log_flush_callback: Option<Arc<dyn Fn(&Attributes) + Send + Sync>>,

}

impl Attributes {

/// New handle for library configuration

///

/// See also [`Attributes::new_image()`]

#[inline]

#[must_use]

pub fn new() -> Self {

let mut attr = Self {

target_mse: 0.,

max_mse: None,

max_colors: MAX_COLORS as PalLen,

last_index_transparent: false,

kmeans_iteration_limit: 0.,

max_histogram_entries: 0,

min_posterization_output: 0,

min_posterization_input: 0,

kmeans_iterations: 0,

feedback_loop_trials: 0,

use_contrast_maps: false,

use_dither_map: DitherMapMode::None,

single_threaded_dithering: false,

speed: 0,

progress_stage1: 0,

progress_stage2: 0,

progress_stage3: 0,

progress_callback: None,

log_callback: None,

log_flush_callback: None,

};

let _ = attr.set_speed(4);

attr

}

/// Make an image from RGBA pixels.

///

/// The `pixels` argument can be `Vec<RGBA>`, or `Box<[RGBA]>` or `&[RGBA]`.

/// See [`Attributes::new_image_borrowed`] for a non-copying alternative.

///

/// Use 0.0 for gamma if the image is sRGB (most images are).

#[inline]

pub fn new_image<VecRGBA>(&self, pixels: VecRGBA, width: usize, height: usize, gamma: f64) -> Result<Image<'static>, Error> where VecRGBA: Into<Box<[RGBA]>> {

Image::new(self, pixels, width, height, gamma)

}

/// Generate palette for the image

pub fn quantize(&self, image: &mut Image<'_>) -> Result<QuantizationResult, Error> {

let mut hist = Histogram::new(self);

hist.add_image(self, image)?;

hist.quantize_internal(self, false)

}

/// It's better to use `set_quality()`

#[inline]

pub fn set_max_colors(&mut self, colors: u32) -> Result<(), Error> {

if !(2..=256).contains(&colors) {

return Err(Error::ValueOutOfRange);

}

self.max_colors = colors as PalLen;

Ok(())

}

/// Range 0-100, roughly like JPEG.

///

/// If the minimum quality can't be met, the quantization will be aborted with an error.

///

/// Default is min 0, max 100, which means best effort, and never aborts the process.

///

/// If max is less than 100, the library will try to use fewer colors.

/// Images with fewer colors are not always smaller, due to increased dithering it causes.

pub fn set_quality(&mut self, minimum: u8, target: u8) -> Result<(), Error> {

if !(0..=100).contains(&target) || target < minimum {

return Err(Error::ValueOutOfRange);

}

if target < 30 {

self.verbose_print(" warning: quality set too low");

}

self.target_mse = quality_to_mse(target);

self.max_mse = Some(quality_to_mse(minimum));

Ok(())

}

/// 1-10.

///

/// Faster speeds generate images of lower quality, but may be useful

/// for real-time generation of images.

///

/// The default is 4.

#[inline]

pub fn set_speed(&mut self, value: i32) -> Result<(), Error> {

if !(1..=10).contains(&value) {

return Err(Error::ValueOutOfRange);

}

let mut iterations = (8 - value).max(0) as u16;

iterations += iterations * iterations / 2;

self.kmeans_iterations = iterations;

self.kmeans_iteration_limit = 1. / f64::from(1 << (23 - value));

self.feedback_loop_trials = (56 - 9 * value).max(0) as _;

self.max_histogram_entries = ((1 << 17) + (1 << 18) * (10 - value)) as _;

self.min_posterization_input = if value >= 8 { 1 } else { 0 };

self.use_dither_map = if value <= 6 { DitherMapMode::Enabled } else { DitherMapMode::None };

if self.use_dither_map != DitherMapMode::None && value < 3 {

self.use_dither_map = DitherMapMode::Always;

}

self.use_contrast_maps = (value <= 7) || self.use_dither_map != DitherMapMode::None;

self.single_threaded_dithering = value == 1;

self.speed = value as u8;

self.progress_stage1 = if self.use_contrast_maps { 20 } else { 8 };

if self.feedback_loop_trials < 2 {

self.progress_stage1 += 30;

}

self.progress_stage3 = (50 / (1 + value)) as u8;

self.progress_stage2 = 100 - self.progress_stage1 - self.progress_stage3;

Ok(())

}

/// Number of least significant bits to ignore.

///

/// Useful for generating palettes for VGA, 15-bit textures, or other retro platforms.

#[inline]

pub fn set_min_posterization(&mut self, value: u8) -> Result<(), Error> {

if !(0..=4).contains(&value) {

return Err(Error::ValueOutOfRange);

}

self.min_posterization_output = value;

Ok(())

}

/// Returns number of bits of precision truncated

#[inline(always)]

#[must_use]

pub fn min_posterization(&self) -> u8 {

self.min_posterization_output

}

/// Return currently set speed/quality trade-off setting

#[inline(always)]

#[must_use]

pub fn speed(&self) -> u32 {

self.speed.into()

}

/// Return max number of colors set

#[inline(always)]

#[must_use]

pub fn max_colors(&self) -> u32 {

self.max_colors.into()

}

/// Reads values set with `set_quality`

#[must_use]

pub fn quality(&self) -> (u8, u8) {

(

self.max_mse.map_or(0, mse_to_quality),

mse_to_quality(self.target_mse),

)

}

/// Describe dimensions of a slice of RGBA pixels

///

/// Use 0.0 for gamma if the image is sRGB (most images are).

#[inline]

pub fn new_image_borrowed<'pixels>(&self, bitmap: &'pixels [RGBA], width: usize, height: usize, gamma: f64) -> Result<Image<'pixels>, Error> {

Image::new_borrowed(self, bitmap, width, height, gamma)

}

/// Like `new_image_stride_borrowed`, but makes a copy of the pixels.

///

/// The `pixels` argument can be `Vec<RGBA>`, or `Box<[RGBA]>` or `&[RGBA]`.

#[inline]

pub fn new_image_stride<VecRGBA>(&self, pixels: VecRGBA, width: usize, height: usize, stride: usize, gamma: f64) -> Result<Image<'static>, Error> where VecRGBA: Into<Box<[RGBA]>> {

Image::new_stride(self, pixels, width, height, stride, gamma)

}

#[doc(hidden)]

#[deprecated(note = "use new_image_stride")]

#[cold]

pub fn new_image_stride_copy(&self, bitmap: &[RGBA], width: usize, height: usize, stride: usize, gamma: f64) -> Result<Image<'static>, Error> {

self.new_image_stride(bitmap, width, height, stride, gamma)

}

/// Set callback function to be called every time the library wants to print a message.

///

/// To share data with the callback, use `Arc` or `Atomic*` types and `move ||` closures.

#[inline]

pub fn set_log_callback<F: Fn(&Self, &str) + Send + Sync + 'static>(&mut self, callback: F) {

self.verbose_printf_flush();

self.log_callback = Some(Arc::new(callback));

}

/// Drop callback from `set_log_callback`

pub fn clear_log_callback(&mut self) {

self.log_callback = None;

}

/// Callback for flushing output (if you buffer messages, that's the time to flush those buffers)

#[inline]

pub fn set_log_flush_callback<F: Fn(&Self) + Send + Sync + 'static>(&mut self, callback: F) {

self.verbose_printf_flush();

self.log_flush_callback = Some(Arc::new(callback));

}

/// Drop callback from `set_log_flush_callback`

#[inline]

pub fn clear_log_flush_callback(&mut self) {

self.verbose_printf_flush();

self.log_flush_callback = None;

}

/// Set callback function to be called every time the library makes a progress.

/// It can be used to cancel operation early.

///

/// To share data with the callback, use `Arc` or `Atomic*` types and `move ||` closures.

#[inline]

pub fn set_progress_callback<F: Fn(f32) -> ControlFlow + Send + Sync + 'static>(&mut self, callback: F) {

self.progress_callback = Some(Arc::new(callback));

}

/// Drop callback from `set_progress_callback`

pub fn clear_progress_callback(&mut self) {

self.progress_callback = None;

}

/// Move transparent color to the last entry in the palette

///

/// This is less efficient for PNG, but required by some broken software

#[inline(always)]

pub fn set_last_index_transparent(&mut self, is_last: bool) {

self.last_index_transparent = is_last;

}

// true == abort

#[inline]

#[must_use]

pub(crate) fn progress(&self, percent: f32) -> bool {

if let Some(f) = &self.progress_callback {

f(percent) == ControlFlow::Break

} else {

false

}

#[inline(always)]

pub(crate) fn verbose_print(&self, msg: impl AsRef<str>) {

fn print_(a: &Attributes, msg: &str) {

if let Some(f) = &a.log_callback {

f(a, msg);

}

print_(self, msg.as_ref());

}

#[inline]

pub(crate) fn verbose_printf_flush(&self) {

if let Some(f) = &self.log_flush_callback {

f(self);

}

#[must_use]

pub(crate) fn feedback_loop_trials(&self, hist_items: usize) -> u16 {

let mut feedback_loop_trials = self.feedback_loop_trials;

if hist_items > 5000 {

feedback_loop_trials = (feedback_loop_trials * 3 + 3) / 4;

}

if hist_items > 25000 {

feedback_loop_trials = (feedback_loop_trials * 3 + 3) / 4;

}

if hist_items > 50000 {

feedback_loop_trials = (feedback_loop_trials * 3 + 3) / 4;

}

if hist_items > 100_000 {

feedback_loop_trials = (feedback_loop_trials * 3 + 3) / 4;

}

feedback_loop_trials

}

/// `max_mse`, `target_mse`, user asked for perfect quality

pub(crate) fn target_mse(&self, hist_items_len: usize) -> (Option<f64>, f64, bool) {

let max_mse = self.max_mse.map(|mse| mse * if hist_items_len <= MAX_COLORS { 0.33 } else { 1. });

let aim_for_perfect_quality = self.target_mse == 0.;

let mut target_mse = self.target_mse.max((f64::from(1 << self.min_posterization_output) / 1024.).powi(2));

if let Some(max_mse) = max_mse {

target_mse = target_mse.min(max_mse);

}

(max_mse, target_mse, aim_for_perfect_quality)

}

/// returns iterations, `iteration_limit`

#[must_use]

pub(crate) fn kmeans_iterations(&self, hist_items_len: usize, palette_error_is_known: bool) -> (u16, f64) {

let mut iteration_limit = self.kmeans_iteration_limit;

let mut iterations = self.kmeans_iterations;

if hist_items_len > 5000 {

iterations = (iterations * 3 + 3) / 4;

}

if hist_items_len > 25000 {

iterations = (iterations * 3 + 3) / 4;

}

if hist_items_len > 50000 {

iterations = (iterations * 3 + 3) / 4;

}

if hist_items_len > 100_000 {

iterations = (iterations * 3 + 3) / 4;

iteration_limit *= 2.;

}

if iterations == 0 && !palette_error_is_known && self.max_mse.is_some() {

iterations = 1;

}

(iterations, iteration_limit)

}

#[inline]

#[must_use]

pub(crate) fn posterize_bits(&self) -> u8 {

self.min_posterization_output.max(self.min_posterization_input)

}

impl Drop for Attributes {

fn drop(&mut self) {

self.verbose_printf_flush();

}

impl Default for Attributes {

#[inline(always)]

fn default() -> Self {

Self::new()

}

/// Result of callback in [`Attributes::set_progress_callback`]

#[derive(Clone, Copy, Debug, Eq, PartialEq)]

#[repr(C)]

pub enum ControlFlow {

/// Continue processing as normal

Continue = 1,

/// Abort processing and fail

Break = 0,

}

#[test]

fn counters() {

let mut a = Attributes::new();

a.set_speed(10).unwrap();

let (iter, _) = a.kmeans_iterations(1000, false);

assert_eq!(iter, 0);

a.set_quality(80, 90).unwrap();

let (iter, limit) = a.kmeans_iterations(1000, false);

assert_eq!(iter, 1);

assert!(limit > 0. && limit < 0.01);

let (iter, _) = a.kmeans_iterations(1000, true);

assert_eq!(iter, 0);

let mut a = Attributes::new();

a.set_quality(50, 80).unwrap();

let (max_mse, target_mse, aim_perfect) = a.target_mse(10000);

let max_mse = max_mse.unwrap();

assert!(!aim_perfect);

assert!(target_mse > 0. && target_mse < 0.01);

assert!(max_mse > 0. && max_mse > target_mse && max_mse < 0.01);

}

#[test]

fn getset() {

let mut a = Attributes::new();

assert!(a.set_quality(0, 101).is_err());

assert!(a.set_quality(50, 49).is_err());

assert!(a.feedback_loop_trials(1000) > 0);

let (max_mse, target_mse, aim_perfect) = a.target_mse(10000);

assert!(aim_perfect);

assert!(target_mse < 0.0001);

assert_eq!(max_mse, None);

a.set_speed(5).unwrap();

assert_eq!(5, a.speed());

assert!(a.set_speed(99).is_err());

assert!(a.set_speed(0).is_err());

a.set_max_colors(5).unwrap();

assert_eq!(5, a.max_colors());

assert!(a.set_max_colors(0).is_err());

a.set_min_posterization(2).unwrap();

assert_eq!(2, a.min_posterization());

assert_eq!(2, a.posterize_bits());

assert!(a.set_min_posterization(8).is_err());

let mut a = Attributes::new();

a.set_speed(10).unwrap();

assert_eq!(1, a.posterize_bits());

}

libimagequant/src/attr.rs at main · ImageOptim/libimagequant · GitHub

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