feat: SOTA sharpening tool with 3 methods and 7 presets (#56)

* feat(sharpening): add SharpenAdvancedOptions type for multi-method sharpening

* feat(sharpening): implement 3-method sharpen engine (adaptive, USM, high-pass)

* feat(sharpening): add dedicated API route with Zod validation

* feat(sharpening): register tool in constants, i18n, and suggested tools

* feat(sharpening): add settings UI with presets, methods, and advanced controls

* feat(sharpening): register tool in frontend registry with before-after display

---------

Co-authored-by: stirling-image <stirling-image@users.noreply.github.com>

apps/api/src/routes/tools/index.ts

@@ -30,6 +30,7 @@ import { registerRemoveBackground } from "./remove-background.js";
 import { registerReplaceColor } from "./replace-color.js";
 import { registerResize } from "./resize.js";
 import { registerRotate } from "./rotate.js";
+import { registerSharpening } from "./sharpening.js";
 import { registerSmartCrop } from "./smart-crop.js";
 import { registerSplit } from "./split.js";
 import { registerStitch } from "./stitch.js";
@@ -84,6 +85,7 @@ export async function registerToolRoutes(app: FastifyInstance): Promise<void> {
     { id: "strip-metadata", register: registerStripMetadata },
     { id: "edit-metadata", register: registerEditMetadata },
     { id: "color-adjustments", register: registerColorAdjustments },
+    { id: "sharpening", register: registerSharpening },
 
     // Watermark & Overlay
     { id: "watermark-text", register: registerWatermarkText },

apps/api/src/routes/tools/sharpening.ts

@@ -0,0 +1,58 @@
+import { sharpenAdvanced } from "@stirling-image/image-engine";
+import type { FastifyInstance } from "fastify";
+import sharp from "sharp";
+import { z } from "zod";
+import { resolveOutputFormat } from "../../lib/output-format.js";
+import { createToolRoute } from "../tool-factory.js";
+
+const settingsSchema = z.object({
+  method: z.enum(["adaptive", "unsharp-mask", "high-pass"]).default("adaptive"),
+  // Adaptive
+  sigma: z.number().min(0.5).max(10).default(1.0),
+  m1: z.number().min(0).max(10).default(1.0),
+  m2: z.number().min(0).max(20).default(3.0),
+  x1: z.number().min(0).max(10).default(2.0),
+  y2: z.number().min(0).max(50).default(12),
+  y3: z.number().min(0).max(50).default(20),
+  // Unsharp Mask
+  amount: z.number().min(0).max(500).default(100),
+  radius: z.number().min(0.1).max(5).default(1.0),
+  threshold: z.number().min(0).max(255).default(0),
+  // High-Pass
+  strength: z.number().min(0).max(100).default(50),
+  kernelSize: z.union([z.literal(3), z.literal(5)]).default(3),
+  // Noise reduction
+  denoise: z.enum(["off", "light", "medium", "strong"]).default("off"),
+});
+
+export function registerSharpening(app: FastifyInstance) {
+  createToolRoute(app, {
+    toolId: "sharpening",
+    settingsSchema,
+    process: async (inputBuffer, settings, filename) => {
+      const outputFormat = await resolveOutputFormat(inputBuffer, filename);
+      let image = sharp(inputBuffer);
+
+      image = await sharpenAdvanced(image, {
+        method: settings.method,
+        sigma: settings.sigma,
+        m1: settings.m1,
+        m2: settings.m2,
+        x1: settings.x1,
+        y2: settings.y2,
+        y3: settings.y3,
+        amount: settings.amount,
+        radius: settings.radius,
+        threshold: settings.threshold,
+        strength: settings.strength,
+        kernelSize: settings.kernelSize,
+        denoise: settings.denoise,
+      });
+
+      const buffer = await image
+        .toFormat(outputFormat.format, { quality: outputFormat.quality })
+        .toBuffer();
+      return { buffer, filename, contentType: outputFormat.contentType };
+    },
+  });
+}