✨[Feat] Sprint 14 Image Compressor

CHANGELOG.md

@@ -6,6 +6,8 @@
 
 - Started the v2 cycle with a production Image category and local Image Converter.
 - Added Image Resize with pixel and percentage modes, aspect-ratio preservation, optional enlargement, Original/JPEG/PNG/WebP output, and local batch ZIP saving.
+- Added Image Compressor with Original/JPEG/PNG/WebP output, truthful format-specific quality behavior, unchanged dimensions, and local batch ZIP saving.
+- Added per-file and aggregate compression metrics that distinguish byte savings from larger generated results.
 - Added per-image output dimension/pixel checks and a 200-megapixel aggregate resize-output workload limit.
 - Added JPEG, PNG, and WebP input/output, lossy quality controls for JPEG/WebP, deterministic white JPEG transparency, metadata-stripping canvas re-encoding, collision-safe Unicode names, and ZIP batch output.
 - Added per-file, queue, dimension, decoded-pixel, and 200-megapixel aggregate-work protections with recoverable errors.

README.md

@@ -10,6 +10,7 @@ The v1 baseline is recorded in the [changelog](./CHANGELOG.md) and historical [v
 
 - [Image Converter](./tools/image/converter/) — convert batches of JPEG, PNG, and WebP images locally with predictable names and ZIP output.
 - [Image Resize](./tools/image/resize/) — resize image batches by pixels or percentage while preserving aspect ratio by default.
+- [Image Compressor](./tools/image/compress/) — quality-compress image batches locally and compare original and result sizes.
 - [Images to PDF](./tools/pdf/images-to-pdf/) — arrange JPEG, PNG, and WebP images and save them as one PDF.
 - [Merge PDF](./tools/pdf/merge/) — validate, order, and combine PDF pages without rasterizing them.
 - [Split PDF](./tools/pdf/split/) — extract ordered page ranges or create predictable per-page and fixed-interval archives.
@@ -156,6 +157,18 @@ Image Resize is available at `/tools/image/resize/` on the v2 integration branch
 - Enforces the shared 50 MiB file, 100-file queue, 500 MiB queue, 16,384-pixel dimension, and 50-megapixel per-image limits, plus a 200-megapixel aggregate output-work limit.
 - Keeps the queue available after validation, decode, canvas, encoding, archive, save, or cancellation errors so settings can be corrected and retried.
 
+## Image Compressor
+
+Image Compressor is available at `/tools/image/compress/` on the v2 integration branch.
+
+- Accepts signature-validated JPEG, PNG, and WebP images and preserves their oriented pixel dimensions while processing sequentially in browser memory.
+- Defaults to Original format. JPEG and WebP use an explicit 50–100% quality setting; PNG is re-encoded without a fake lossy-quality control, so size reduction may be limited.
+- Reports original size, result size, byte difference, and signed percentage change for every file, plus aggregate batch totals. Larger results are kept and labeled as increases rather than savings.
+- Preserves alpha for PNG/WebP and flattens transparent pixels onto white for JPEG. Canvas re-encoding strips EXIF and other embedded metadata.
+- Uses collision-safe Unicode `_compressed` names and saves multiple outputs as `compressed_images.zip` through the same-origin JSZip dependency.
+- Reuses the established input, queue, dimension, 50-megapixel per-image, and 200-megapixel aggregate decoded-work limits. Queues remain available after recoverable failures or save cancellation.
+- Performs no target-size search, resizing, cropping, metadata editing, upload, analytics, telemetry, remote codec, or runtime network request.
+
 ## Images to PDF
 
 Images to PDF is available at `/tools/pdf/images-to-pdf/`.

js/i18n.js

@@ -5,13 +5,15 @@ import { es } from "./locales/es.js";
 import { de } from "./locales/de.js";
 import { fr } from "./locales/fr.js";
 import { imageResizeLocales } from "./locales/image-resize.js";
+import { imageCompressorLocales } from "./locales/image-compressor.js";
 
 const STORAGE_KEY = "secure-tools-language";
 const baseTranslations = { en, ko, ja, es, de, fr };
 export const translations = Object.fromEntries(Object.entries(baseTranslations).map(([language, catalog]) => [language, {
   ...catalog,
-  metadata: { ...catalog.metadata, imageResize: imageResizeLocales[language].metadata },
+  metadata: { ...catalog.metadata, imageResize: imageResizeLocales[language].metadata, imageCompressor: imageCompressorLocales[language].metadata },
   imageResize: imageResizeLocales[language].copy,
+  imageCompressor: imageCompressorLocales[language].copy,
 }]));
 
 export function resolveLanguage(value, availableLanguages = Object.keys(translations)) {

tests/i18n-quality.test.mjs

@@ -45,7 +45,7 @@ function placeholders(value) {
 function testCatalogParityAndQuality() {
   assert.deepEqual([...Object.keys(translations)], [...languageNames.keys()]);
   const english = flatten(translations.en);
-  assert.equal(english.size, 597);
+  assert.equal(english.size, 632);
 
   for (const [language, catalog] of Object.entries(translations)) {
     const flattened = flatten(catalog);
@@ -77,7 +77,7 @@ function testResolutionDetectionAndPersistence() {
 
 function testSelectorsAndDocumentTranslation() {
   const pages = listFiles(root, (file) => file.endsWith(".html") && fs.readFileSync(file, "utf8").includes("data-language-select"));
-  assert.equal(pages.length, 17, "Every production page with the shared header must expose the language selector");
+  assert.equal(pages.length, 18, "Every production page with the shared header must expose the language selector");
   for (const file of pages) {
     const html = fs.readFileSync(file, "utf8");
     const select = html.match(/<select[^>]*data-language-select[^>]*>([\s\S]*?)<\/select>/)?.[1];