Add ImageQuant support

cli/src/codecs.js

@@ -26,14 +26,21 @@ const pngEncDecPromise = pngEncDec.default(
   fsp.readFile(pathify(pngEncDecWasm))
 );
 
+// OxiPNG
 import * as oxipng from "../../codecs/oxipng/pkg/squoosh_oxipng.js";
 import oxipngWasm from "asset-url:../../codecs/oxipng/pkg/squoosh_oxipng_bg.wasm";
 const oxipngPromise = oxipng.default(fsp.readFile(pathify(oxipngWasm)));
 
+// Resize
 import * as resize from "../../codecs/resize/pkg/squoosh_resize.js";
 import resizeWasm from "asset-url:../../codecs/resize/pkg/squoosh_resize_bg.wasm";
 const resizePromise = resize.default(fsp.readFile(pathify(resizeWasm)));
 
+// ImageQuant
+import imageQuant from "../../codecs/imagequant/imagequant.js";
+import imageQuantWasm from "asset-url:../../codecs/imagequant/imagequant.wasm";
+const imageQuantPromise = instantiateEmscriptenWasm(imageQuant, imageQuantWasm);
+
 // Our decoders currently rely on a `ImageData` global.
 import ImageData from "./image_data.js";
 globalThis.ImageData = ImageData;
@@ -114,12 +121,28 @@ export const preprocessors = {
       };
     },
     defaultOptions: {
-      // This will be set to 'vector' if the input is SVG.
       method: "lanczos3",
       fitMethod: "stretch",
       premultiply: true,
       linearRGB: true
     }
+  },
+  quant: {
+    name: "ImageQuant",
+    description: "Reduce the number of colors used (aka. paletting)",
+    instantiate: async () => {
+      const imageQuant = await imageQuantPromise;
+      return (buffer, width, height, { numColors, dither }) =>
+        new ImageData(
+          imageQuant.quantize(buffer, width, height, numColors, dither),
+          width,
+          height
+        );
+    },
+    defaultOptions: {
+      numColors: 255,
+      dither: 1.0
+    }
   }
 };
 

cli/src/index.js

@@ -5,10 +5,10 @@ import { cpus } from "os";
 import { extname, join, basename } from "path";
 import { promises as fsp } from "fs";
 import { version } from "json:../package.json";
-import ora from 'ora';
+import ora from "ora";
-import kleur from 'kleur';
+import kleur from "kleur";
 
-import {codecs as supportedFormats, preprocessors} from "./codecs.js";
+import { codecs as supportedFormats, preprocessors } from "./codecs.js";
 import WorkerPool from "./worker_pool.js";
 import { autoOptimize } from "./auto-optimizer.js";
 
@@ -47,13 +47,14 @@ async function decodeFile(file) {
   };
 }
 
-async function preprocessImage({
+async function preprocessImage({ preprocessorName, options, file }) {
-	preprocessorName,
-	options,
-	file
-}) {
   const preprocessor = await preprocessors[preprocessorName].instantiate();
-	file.bitmap= await preprocessor(file.bitmap.data, file.bitmap.width, file.bitmap.height, options);
+  file.bitmap = await preprocessor(
+    file.bitmap.data,
+    file.bitmap.width,
+    file.bitmap.height,
+    options
+  );
   return file;
 }
 
@@ -120,7 +121,7 @@ async function encodeFile({
 // both decoding and encoding go through the worker pool
 function handleJob(params) {
   const { operation } = params;
-	switch(operation) {
+  switch (operation) {
     case "encode":
       return encodeFile(params);
     case "decode":
@@ -138,37 +139,44 @@ function progressTracker(results) {
   tracker.spinner = spinner;
   tracker.progressOffset = 0;
   tracker.totalOffset = 0;
-  let status = '';
+  let status = "";
-  tracker.setStatus = (text) => {
+  tracker.setStatus = text => {
-    status = text || '';
+    status = text || "";
     update();
   };
-  let progress = '';
+  let progress = "";
   tracker.setProgress = (done, total) => {
     spinner.prefixText = kleur.dim(`${done}/${total}`);
-    const completeness = (tracker.progressOffset + done) / (tracker.totalOffset + total);
+    const completeness =
-    progress = kleur.cyan(`▐${'▨'.repeat(completeness*10|0).padEnd(10, '╌')}▌ `);
+      (tracker.progressOffset + done) / (tracker.totalOffset + total);
+    progress = kleur.cyan(
+      `▐${"▨".repeat((completeness * 10) | 0).padEnd(10, "╌")}▌ `
+    );
     update();
   };
   function update() {
     spinner.text = progress + kleur.bold(status) + getResultsText();
   }
-  tracker.finish = (text) => {
+  tracker.finish = text => {
     spinner.succeed(kleur.bold(text) + getResultsText());
-  }
+  };
   function getResultsText() {
-    let out = '';
+    let out = "";
     for (const [filename, result] of results.entries()) {
       out += `\n ${kleur.cyan(filename)}: ${prettyPrintSize(result.size)}`;
       for (const { outputFile, outputSize, infoText } of result.outputs) {
         const name = (program.suffix + extname(outputFile)).padEnd(5);
-        out += `\n  ${kleur.dim('└')} ${kleur.cyan(name)} → ${prettyPrintSize(outputSize)}`;
+        out += `\n  ${kleur.dim("└")} ${kleur.cyan(name)} → ${prettyPrintSize(
+          outputSize
+        )}`;
         const percent = ((outputSize / result.size) * 100).toPrecision(3);
-        out += ` (${kleur[outputSize>result.size?'red':'green'](percent+'%')})`;
+        out += ` (${kleur[outputSize > result.size ? "red" : "green"](
+          percent + "%"
+        )})`;
         if (infoText) out += kleur.yellow(infoText);
       }
     }
-    return out || '\n';
+    return out || "\n";
   }
   spinner.start();
   return tracker;
@@ -180,7 +188,7 @@ async function processFiles(files) {
   const results = new Map();
   const progress = progressTracker(results);
 
-  progress.setStatus('Decoding...');
+  progress.setStatus("Decoding...");
   progress.totalOffset = files.length;
   progress.setProgress(0, files.length);
 
@@ -189,8 +197,12 @@ async function processFiles(files) {
   await fsp.mkdir(program.outputDir, { recursive: true });
 
   let decoded = 0;
-  let decodedFiles = await Promise.all(files.map(async file => {
+  let decodedFiles = await Promise.all(
-    const result = await workerPool.dispatchJob({ operation: 'decode', file });
+    files.map(async file => {
+      const result = await workerPool.dispatchJob({
+        operation: "decode",
+        file
+      });
       results.set(file, {
         file: result.file,
         size: result.size,
@@ -198,10 +210,11 @@ async function processFiles(files) {
       });
       progress.setProgress(++decoded, files.length);
       return result;
-  }));
+    })
+  );
 
   for (const [preprocessorName, value] of Object.entries(preprocessors)) {
-		if(!program[preprocessorName]) {
+    if (!program[preprocessorName]) {
       continue;
     }
     const preprocessorParam = program[preprocessorName];
@@ -211,22 +224,23 @@ async function processFiles(files) {
       JSON5.parse(preprocessorParam)
     );
 
-		decodedFiles = await Promise.all(decodedFiles.map(async file => {
+    decodedFiles = await Promise.all(
+      decodedFiles.map(async file => {
         return workerPool.dispatchJob({
           file,
           operation: "preprocess",
           preprocessorName,
           options: preprocessorOptions
         });
-		}));
+      })
+    );
 
     for (const { file, bitmap, size } of decodedFiles) {
-		
     }
   }
 
   progress.progressOffset = decoded;
-  progress.setStatus('Encoding ' + kleur.dim(`(${parallelism} threads)`));
+  progress.setStatus("Encoding " + kleur.dim(`(${parallelism} threads)`));
   progress.setProgress(0, files.length);
 
   const jobs = [];
@@ -254,17 +268,19 @@ async function processFiles(files) {
       jobsStarted++;
       const p = workerPool
         .dispatchJob({
-          operation: 'encode',
+          operation: "encode",
           file,
           size,
           bitmap,
           outputFile,
           encName,
           encConfig,
-          optimizerButteraugliTarget: Number(program.optimizerButteraugliTarget),
+          optimizerButteraugliTarget: Number(
+            program.optimizerButteraugliTarget
+          ),
           maxOptimizerRounds: Number(program.maxOptimizerRounds)
         })
-        .then((output) => {
+        .then(output => {
           jobsFinished++;
           results.get(file).outputs.push(output);
           progress.setProgress(jobsFinished, jobsStarted);
@@ -278,7 +294,7 @@ async function processFiles(files) {
   // Wait for all jobs to finish
   await workerPool.join();
   await Promise.all(jobs);
-  progress.finish('Squoosh results:');
+  progress.finish("Squoosh results:");
 }
 
 if (isMainThread) {
@@ -291,21 +307,18 @@ if (isMainThread) {
     .option(
       "--max-optimizer-rounds <rounds>",
       "Maximum number of compressions to use for auto optimizations",
-      '6'
+      "6"
     )
     .option(
       "--optimizer-butteraugli-target <butteraugli distance>",
       "Target Butteraugli distance for auto optimizer",
-      '1.4'
+      "1.4"
     )
     .action(processFiles);
 
   // Create a CLI option for each supported preprocessor
   for (const [key, value] of Object.entries(preprocessors)) {
-    program.option(
+    program.option(`--${key} [config]`, value.description);
-      `--${key} [config]`,
-	  value.description
-    );
   }
   // Create a CLI option for each supported encoder
   for (const [key, value] of Object.entries(supportedFormats)) {