Merge branch 'feat/remove-bg-improvements'

apps/api/src/lib/bg-effects.ts

@@ -1,5 +1,26 @@
 import sharp from "sharp";
 
+export type BgOutputFormat = "png" | "webp" | "avif";
+
+export const BG_OUTPUT_FORMATS: BgOutputFormat[] = ["png", "webp", "avif"];
+
+export const BG_FORMAT_CONTENT_TYPES: Record<BgOutputFormat, string> = {
+  png: "image/png",
+  webp: "image/webp",
+  avif: "image/avif",
+};
+
+function toOutputFormat(pipeline: sharp.Sharp, format: BgOutputFormat): Promise<Buffer> {
+  switch (format) {
+    case "webp":
+      return pipeline.webp({ lossless: true }).toBuffer();
+    case "avif":
+      return pipeline.avif({ lossless: true }).toBuffer();
+    default:
+      return pipeline.png().toBuffer();
+  }
+}
+
 /**
  * Background removal post-processing effects.
  * All effects use Sharp (libvips) for fast server-side image manipulation.
@@ -182,6 +203,7 @@ export async function applyEffects(
     blurIntensity?: number;
     shadowEnabled?: boolean;
     shadowOpacity?: number;
+    outputFormat?: BgOutputFormat;
   },
 ): Promise<Buffer> {
   const meta = await sharp(subjectBuffer).metadata();
@@ -238,13 +260,12 @@ export async function applyEffects(
   }
   // else: transparent - no background layer
 
+  const fmt = settings.outputFormat ?? "png";
+
   // Step 3: Composite subject onto background
   if (background) {
-    return sharp(background)
+    return toOutputFormat(sharp(background).composite([{ input: subject, blend: "over" }]), fmt);
-      .composite([{ input: subject, blend: "over" }])
-      .png()
-      .toBuffer();
   }
 
-  return subject;
+  return toOutputFormat(sharp(subject), fmt);
 }

apps/api/src/routes/tools/remove-background.ts

@@ -6,7 +6,11 @@ import { getBundleForTool, TOOL_BUNDLE_MAP } from "@snapotter/shared";
 import type { FastifyInstance, FastifyReply, FastifyRequest } from "fastify";
 import { z } from "zod";
 import { autoOrient } from "../../lib/auto-orient.js";
-import { applyEffects } from "../../lib/bg-effects.js";
+import {
+  applyEffects,
+  BG_FORMAT_CONTENT_TYPES,
+  type BgOutputFormat,
+} from "../../lib/bg-effects.js";
 import { formatZodErrors } from "../../lib/errors.js";
 import { isToolInstalled } from "../../lib/feature-status.js";
 import { validateImageBuffer } from "../../lib/file-validation.js";
@@ -28,6 +32,9 @@ const settingsSchema = z.object({
   blurIntensity: z.number().min(0).max(100).optional(),
   shadowEnabled: z.boolean().optional(),
   shadowOpacity: z.number().min(0).max(100).optional(),
+  outputFormat: z.enum(["png", "webp", "avif"]).optional(),
+  edgeRefine: z.number().int().min(0).max(3).optional(),
+  decontaminate: z.boolean().optional(),
 });
 
 /**
@@ -176,7 +183,11 @@ export function registerRemoveBackground(app: FastifyInstance) {
         const transparentResult = await removeBackground(
           fileBuffer,
           join(workspacePath, "output"),
-          { model: settings.model },
+          {
+            model: settings.model,
+            edgeRefine: settings.edgeRefine,
+            decontaminate: settings.decontaminate,
+          },
           onProgress,
         );
 
@@ -265,6 +276,7 @@ export function registerRemoveBackground(app: FastifyInstance) {
         blurIntensity: z.number().min(0).max(100).optional(),
         shadowEnabled: z.boolean().optional(),
         shadowOpacity: z.number().min(0).max(100).optional(),
+        outputFormat: z.enum(["png", "webp", "avif"]).optional(),
       });
 
       try {
@@ -308,6 +320,7 @@ export function registerRemoveBackground(app: FastifyInstance) {
         }
 
         // Apply effects using cached mask + original
+        const fmt = (settings.outputFormat ?? "png") as BgOutputFormat;
         const resultBuffer = await applyEffects(maskBuffer, originalBuffer, {
           backgroundType: settings.backgroundType,
           backgroundColor: settings.backgroundColor,
@@ -319,10 +332,11 @@ export function registerRemoveBackground(app: FastifyInstance) {
           blurIntensity: settings.blurIntensity,
           shadowEnabled: settings.shadowEnabled,
           shadowOpacity: settings.shadowOpacity,
+          outputFormat: fmt,
         });
 
         // Save the final output
-        const outputFilename = `${baseName}_nobg.png`;
+        const outputFilename = `${baseName}_nobg.${fmt}`;
         const outputPath = join(workspacePath, "output", outputFilename);
         await writeFile(outputPath, resultBuffer);
 
@@ -354,9 +368,10 @@ export function registerRemoveBackground(app: FastifyInstance) {
       const transparentResult = await removeBackground(
         orientedBuffer,
         join(workspacePath, "output"),
-        { model: s.model },
+        { model: s.model, edgeRefine: s.edgeRefine, decontaminate: s.decontaminate },
       );
 
+      const fmt = (s.outputFormat ?? "png") as BgOutputFormat;
       const resultBuffer = await applyEffects(transparentResult, orientedBuffer, {
         backgroundType: s.backgroundType,
         backgroundColor: s.backgroundColor,
@@ -367,10 +382,15 @@ export function registerRemoveBackground(app: FastifyInstance) {
         blurIntensity: s.blurIntensity,
         shadowEnabled: s.shadowEnabled,
         shadowOpacity: s.shadowOpacity,
+        outputFormat: fmt,
       });
 
-      const outputFilename = `${filename.replace(/\.[^.]+$/, "")}_nobg.png`;
+      const outputFilename = `${filename.replace(/\.[^.]+$/, "")}_nobg.${fmt}`;
-      return { buffer: resultBuffer, filename: outputFilename, contentType: "image/png" };
+      return {
+        buffer: resultBuffer,
+        filename: outputFilename,
+        contentType: BG_FORMAT_CONTENT_TYPES[fmt],
+      };
     },
   });
 }

apps/web/src/components/tools/remove-bg-settings.tsx

@@ -22,6 +22,7 @@ type BackgroundType = "transparent" | "color" | "gradient" | "image";
 type BgModel =
   | "birefnet-general"
   | "birefnet-general-lite"
+  | "birefnet-hr-matting"
   | "birefnet-matting"
   | "birefnet-portrait"
   | "bria-rmbg"
@@ -31,8 +32,8 @@ const MODEL_MAP: Record<SubjectType, Partial<Record<Quality, BgModel>>> = {
   people: {
     fast: "u2net",
     balanced: "birefnet-portrait",
-    best: "birefnet-portrait",
+    best: "birefnet-matting",
-    ultra: "birefnet-matting",
+    ultra: "birefnet-hr-matting",
   },
   products: { fast: "u2net", balanced: "bria-rmbg", best: "birefnet-general" },
   general: { fast: "u2net", balanced: "birefnet-general-lite", best: "birefnet-general" },
@@ -105,6 +106,13 @@ export function RemoveBgControls({ settings: _settings, onChange }: RemoveBgCont
   const [shadowEnabled, setShadowEnabled] = useState(false);
   const [shadowOpacity, setShadowOpacity] = useState(35);
 
+  // Post-processing
+  const [edgeRefine, setEdgeRefine] = useState(0);
+  const [decontaminate, setDecontaminate] = useState(false);
+
+  // Output
+  const [outputFormat, setOutputFormat] = useState<"png" | "webp" | "avif">("png");
+
   // Expandable sections
   const [effectsOpen, setEffectsOpen] = useState(false);
 
@@ -152,6 +160,10 @@ export function RemoveBgControls({ settings: _settings, onChange }: RemoveBgCont
       next._bgImageFile = bgImageFile;
     }
 
+    if (edgeRefine > 0) next.edgeRefine = edgeRefine;
+    if (decontaminate) next.decontaminate = true;
+    if (outputFormat !== "png") next.outputFormat = outputFormat;
+
     onChangeRef.current(next);
   }, [
     model,
@@ -165,6 +177,9 @@ export function RemoveBgControls({ settings: _settings, onChange }: RemoveBgCont
     blurIntensity,
     shadowEnabled,
     shadowOpacity,
+    edgeRefine,
+    decontaminate,
+    outputFormat,
   ]);
 
   return (
@@ -387,6 +402,25 @@ export function RemoveBgControls({ settings: _settings, onChange }: RemoveBgCont
         )}
       </div>
 
+      {/* Output format */}
+      <SectionLabel>{t.toolSettings["remove-background"].outputFormat}</SectionLabel>
+      <div className="grid grid-cols-3 gap-1.5">
+        {(["png", "webp", "avif"] as const).map((fmt) => (
+          <button
+            key={fmt}
+            type="button"
+            onClick={() => setOutputFormat(fmt)}
+            className={`py-2 px-2 rounded-lg border text-xs font-medium uppercase transition-colors ${
+              outputFormat === fmt
+                ? "border-primary bg-primary/10 text-primary"
+                : "border-border text-muted-foreground hover:border-primary/50"
+            }`}
+          >
+            {fmt}
+          </button>
+        ))}
+      </div>
+
       {/* Effects */}
       <button
         type="button"
@@ -395,7 +429,7 @@ export function RemoveBgControls({ settings: _settings, onChange }: RemoveBgCont
       >
         {effectsOpen ? <ChevronDown className="h-3 w-3" /> : <ChevronRight className="h-3 w-3" />}
         Effects
-        {(blurEnabled || shadowEnabled) && (
+        {(blurEnabled || shadowEnabled || edgeRefine > 0 || decontaminate) && (
           <span className="ms-auto text-primary text-[10px] normal-case font-normal">active</span>
         )}
       </button>
@@ -467,6 +501,48 @@ export function RemoveBgControls({ settings: _settings, onChange }: RemoveBgCont
               </div>
             )}
           </div>
+
+          {/* Edge smoothing */}
+          <div>
+            <div className="flex justify-between items-center">
+              <span className="text-xs text-muted-foreground">
+                {t.toolSettings["remove-background"].edgeSmoothing}
+              </span>
+              <span className="text-xs font-mono text-foreground tabular-nums">
+                {edgeRefine === 0
+                  ? t.toolSettings["remove-background"].edgeSmoothingOff
+                  : edgeRefine === 1
+                    ? t.toolSettings["remove-background"].edgeSmoothingLight
+                    : edgeRefine === 2
+                      ? t.toolSettings["remove-background"].edgeSmoothingMedium
+                      : t.toolSettings["remove-background"].edgeSmoothingStrong}
+              </span>
+            </div>
+            <input
+              type="range"
+              min={0}
+              max={3}
+              step={1}
+              value={edgeRefine}
+              onChange={(e) => setEdgeRefine(Number(e.target.value))}
+              className="w-full mt-0.5"
+            />
+          </div>
+
+          {/* Color decontamination */}
+          <div>
+            <label className="flex items-center gap-2 cursor-pointer">
+              <input
+                type="checkbox"
+                checked={decontaminate}
+                onChange={(e) => setDecontaminate(e.target.checked)}
+                className="rounded border-border accent-primary"
+              />
+              <span className="text-xs text-muted-foreground">
+                {t.toolSettings["remove-background"].colorDecontamination}
+              </span>
+            </label>
+          </div>
         </div>
       )}
     </div>
@@ -742,6 +818,7 @@ export function RemoveBgSettings({ onBgPreview }: RemoveBgSettingsProps = {}) {
         blurIntensity: settings.blurIntensity,
         shadowEnabled: settings.shadowEnabled,
         shadowOpacity: settings.shadowOpacity,
+        outputFormat: settings.outputFormat,
       };
       formData.append("settings", JSON.stringify(effectSettings));
 

packages/ai/python/remove_bg.py

@@ -5,10 +5,77 @@ import os
 
 
 def emit_progress(percent, stage):
-    """Emit structured progress to stderr for bridge.ts to capture."""
     print(json.dumps({"progress": percent, "stage": stage}), file=sys.stderr, flush=True)
 
 
+def _refine_edges(image_bytes, level):
+    """Morphological mask refinement to reduce gray halos on edges.
+
+    level: 1=light, 2=medium, 3=strong
+    """
+    import cv2
+    import numpy as np
+    from PIL import Image
+    import io
+
+    img = Image.open(io.BytesIO(image_bytes)).convert("RGBA")
+    arr = np.array(img)
+    alpha = arr[:, :, 3]
+
+    kernel_size = 1 + level
+    kernel = cv2.getStructuringElement(cv2.MORPH_ELLIPSE, (kernel_size, kernel_size))
+    alpha = cv2.morphologyEx(alpha, cv2.MORPH_CLOSE, kernel)
+
+    sigma = 0.3 + level * 0.3
+    alpha = cv2.GaussianBlur(alpha, (0, 0), sigma)
+
+    arr[:, :, 3] = alpha
+    out = Image.fromarray(arr, "RGBA")
+    buf = io.BytesIO()
+    out.save(buf, format="PNG")
+    return buf.getvalue()
+
+
+def _decontaminate_edges(image_bytes):
+    """Remove background color spill from semi-transparent edge pixels."""
+    import numpy as np
+    from PIL import Image
+    import io
+
+    img = Image.open(io.BytesIO(image_bytes)).convert("RGBA")
+    arr = np.array(img, dtype=np.float32)
+    alpha = arr[:, :, 3] / 255.0
+    rgb = arr[:, :, :3]
+
+    bg_mask = alpha < 0.04
+    if not np.any(bg_mask):
+        return image_bytes
+
+    bg_color = np.zeros(3, dtype=np.float32)
+    for c in range(3):
+        channel = rgb[:, :, c]
+        bg_pixels = channel[bg_mask]
+        if len(bg_pixels) > 0:
+            bg_color[c] = np.median(bg_pixels)
+
+    edge_mask = (alpha > 0.04) & (alpha < 0.96)
+    if not np.any(edge_mask):
+        return image_bytes
+
+    a = alpha[edge_mask, np.newaxis]
+    fg = rgb[edge_mask]
+    corrected = (fg - bg_color[np.newaxis, :] * (1.0 - a)) / np.maximum(a, 0.01)
+    corrected = np.clip(corrected, 0, 255)
+    rgb[edge_mask] = corrected
+
+    arr[:, :, :3] = rgb
+    result = np.clip(arr, 0, 255).astype(np.uint8)
+    out = Image.fromarray(result, "RGBA")
+    buf = io.BytesIO()
+    out.save(buf, format="PNG")
+    return buf.getvalue()
+
+
 ALLOWED_MODELS = {
     "u2net",
     "isnet-general-use",
@@ -167,6 +234,17 @@ def main():
 
         emit_progress(80, "Background removed")
 
+        edge_refine = settings.get("edgeRefine", 0)
+        decontaminate = settings.get("decontaminate", False)
+
+        if edge_refine and edge_refine > 0:
+            emit_progress(85, "Refining edges")
+            output_data = _refine_edges(output_data, int(edge_refine))
+
+        if decontaminate:
+            emit_progress(90, "Removing color spill")
+            output_data = _decontaminate_edges(output_data)
+
         # Always return transparent PNG. All background compositing
         # (solid color, gradient, blur, shadow) is handled by Node.js/Sharp.
 

packages/ai/src/background-removal.ts

@@ -8,6 +8,8 @@ import { type ProgressCallback, parseStdoutJson, runPythonWithProgress } from ".
 export interface RemoveBackgroundOptions {
   model?: string;
   backgroundColor?: string;
+  edgeRefine?: number;
+  decontaminate?: boolean;
 }
 
 const MAX_REMBG_PX = Number(process.env.MAX_REMBG_PX) || 2048;

packages/shared/src/i18n/ar.ts

@@ -587,6 +587,13 @@ export const ar: TranslationKeys = {
       intensity: "الشدة",
       addShadow: "إضافة ظل",
       opacity: "الشفافية",
+      outputFormat: "Output Format",
+      edgeSmoothing: "Edge Smoothing",
+      edgeSmoothingOff: "Off",
+      edgeSmoothingLight: "Light",
+      edgeSmoothingMedium: "Medium",
+      edgeSmoothingStrong: "Strong",
+      colorDecontamination: "Color Decontamination",
       rendering: "جاري المعالجة...",
       submit: "إزالة الخلفية",
       submitBatch: "إزالة الخلفية ({count} ملف)",

packages/shared/src/i18n/de.ts

@@ -595,6 +595,13 @@ export const de: TranslationKeys = {
       intensity: "Intensitaet",
       addShadow: "Schatten hinzufuegen",
       opacity: "Deckkraft",
+      outputFormat: "Output Format",
+      edgeSmoothing: "Edge Smoothing",
+      edgeSmoothingOff: "Off",
+      edgeSmoothingLight: "Light",
+      edgeSmoothingMedium: "Medium",
+      edgeSmoothingStrong: "Strong",
+      colorDecontamination: "Color Decontamination",
       rendering: "Wird gerendert...",
       submit: "Hintergrund entfernen",
       submitBatch: "Hintergrund entfernen ({count} Dateien)",

packages/shared/src/i18n/en.ts

@@ -545,6 +545,13 @@ export const en = {
       intensity: "Intensity",
       addShadow: "Add Shadow",
       opacity: "Opacity",
+      outputFormat: "Output Format",
+      edgeSmoothing: "Edge Smoothing",
+      edgeSmoothingOff: "Off",
+      edgeSmoothingLight: "Light",
+      edgeSmoothingMedium: "Medium",
+      edgeSmoothingStrong: "Strong",
+      colorDecontamination: "Color Decontamination",
       rendering: "Rendering...",
       submit: "Remove Background",
       submitBatch: "Remove Background ({count} files)",

packages/shared/src/i18n/es.ts

@@ -579,6 +579,13 @@ export const es: TranslationKeys = {
       intensity: "Intensidad",
       addShadow: "Agregar sombra",
       opacity: "Opacidad",
+      outputFormat: "Output Format",
+      edgeSmoothing: "Edge Smoothing",
+      edgeSmoothingOff: "Off",
+      edgeSmoothingLight: "Light",
+      edgeSmoothingMedium: "Medium",
+      edgeSmoothingStrong: "Strong",
+      colorDecontamination: "Color Decontamination",
       rendering: "Renderizando...",
       submit: "Eliminar fondo",
       submitBatch: "Eliminar fondo ({count} archivos)",

packages/shared/src/i18n/fr.ts

@@ -596,6 +596,13 @@ export const fr: TranslationKeys = {
       intensity: "Intensite",
       addShadow: "Ajouter une ombre",
       opacity: "Opacite",
+      outputFormat: "Output Format",
+      edgeSmoothing: "Edge Smoothing",
+      edgeSmoothingOff: "Off",
+      edgeSmoothingLight: "Light",
+      edgeSmoothingMedium: "Medium",
+      edgeSmoothingStrong: "Strong",
+      colorDecontamination: "Color Decontamination",
       rendering: "Rendu en cours...",
       submit: "Supprimer l'arriere-plan",
       submitBatch: "Supprimer l'arriere-plan ({count} fichiers)",

packages/shared/src/i18n/hi.ts

@@ -583,6 +583,13 @@ export const hi: TranslationKeys = {
       intensity: "तीव्रता",
       addShadow: "शैडो जोड़ें",
       opacity: "ओपेसिटी",
+      outputFormat: "Output Format",
+      edgeSmoothing: "Edge Smoothing",
+      edgeSmoothingOff: "Off",
+      edgeSmoothingLight: "Light",
+      edgeSmoothingMedium: "Medium",
+      edgeSmoothingStrong: "Strong",
+      colorDecontamination: "Color Decontamination",
       rendering: "रेंडर हो रहा है...",
       submit: "बैकग्राउंड हटाएं",
       submitBatch: "बैकग्राउंड हटाएं ({count} फाइलें)",

packages/shared/src/i18n/id.ts

@@ -593,6 +593,13 @@ export const id: TranslationKeys = {
       intensity: "Intensitas",
       addShadow: "Tambah Bayangan",
       opacity: "Opasitas",
+      outputFormat: "Output Format",
+      edgeSmoothing: "Edge Smoothing",
+      edgeSmoothingOff: "Off",
+      edgeSmoothingLight: "Light",
+      edgeSmoothingMedium: "Medium",
+      edgeSmoothingStrong: "Strong",
+      colorDecontamination: "Color Decontamination",
       rendering: "Merender...",
       submit: "Hapus Latar Belakang",
       submitBatch: "Hapus Latar Belakang ({count} file)",

packages/shared/src/i18n/it.ts

@@ -592,6 +592,13 @@ export const it: TranslationKeys = {
       intensity: "Intensita",
       addShadow: "Aggiungi ombra",
       opacity: "Opacita",
+      outputFormat: "Output Format",
+      edgeSmoothing: "Edge Smoothing",
+      edgeSmoothingOff: "Off",
+      edgeSmoothingLight: "Light",
+      edgeSmoothingMedium: "Medium",
+      edgeSmoothingStrong: "Strong",
+      colorDecontamination: "Color Decontamination",
       rendering: "Rendering...",
       submit: "Rimuovi sfondo",
       submitBatch: "Rimuovi sfondo ({count} file)",

packages/shared/src/i18n/ja.ts

@@ -552,6 +552,13 @@ export const ja: TranslationKeys = {
       intensity: "強度",
       addShadow: "シャドウ追加",
       opacity: "不透明度",
+      outputFormat: "Output Format",
+      edgeSmoothing: "Edge Smoothing",
+      edgeSmoothingOff: "Off",
+      edgeSmoothingLight: "Light",
+      edgeSmoothingMedium: "Medium",
+      edgeSmoothingStrong: "Strong",
+      colorDecontamination: "Color Decontamination",
       rendering: "レンダリング中...",
       submit: "背景を除去",
       submitBatch: "背景を除去（{count}ファイル）",

packages/shared/src/i18n/ko.ts

@@ -539,6 +539,13 @@ export const ko: TranslationKeys = {
       intensity: "강도",
       addShadow: "그림자 추가",
       opacity: "불투명도",
+      outputFormat: "Output Format",
+      edgeSmoothing: "Edge Smoothing",
+      edgeSmoothingOff: "Off",
+      edgeSmoothingLight: "Light",
+      edgeSmoothingMedium: "Medium",
+      edgeSmoothingStrong: "Strong",
+      colorDecontamination: "Color Decontamination",
       rendering: "렌더링 중...",
       submit: "배경 제거",
       submitBatch: "배경 제거 ({count}개 파일)",

packages/shared/src/i18n/nl.ts

@@ -593,6 +593,13 @@ export const nl: TranslationKeys = {
       intensity: "Intensiteit",
       addShadow: "Schaduw toevoegen",
       opacity: "Dekking",
+      outputFormat: "Output Format",
+      edgeSmoothing: "Edge Smoothing",
+      edgeSmoothingOff: "Off",
+      edgeSmoothingLight: "Light",
+      edgeSmoothingMedium: "Medium",
+      edgeSmoothingStrong: "Strong",
+      colorDecontamination: "Color Decontamination",
       rendering: "Renderen...",
       submit: "Achtergrond verwijderen",
       submitBatch: "Achtergrond verwijderen ({count} bestanden)",

packages/shared/src/i18n/pl.ts

@@ -596,6 +596,13 @@ export const pl: TranslationKeys = {
       intensity: "Intensywność",
       addShadow: "Dodaj cień",
       opacity: "Krycie",
+      outputFormat: "Output Format",
+      edgeSmoothing: "Edge Smoothing",
+      edgeSmoothingOff: "Off",
+      edgeSmoothingLight: "Light",
+      edgeSmoothingMedium: "Medium",
+      edgeSmoothingStrong: "Strong",
+      colorDecontamination: "Color Decontamination",
       rendering: "Renderowanie...",
       submit: "Usuń tło",
       submitBatch: "Usuń tło ({count} plików)",

packages/shared/src/i18n/pt-BR.ts

@@ -592,6 +592,13 @@ export const ptBR: TranslationKeys = {
       intensity: "Intensidade",
       addShadow: "Adicionar sombra",
       opacity: "Opacidade",
+      outputFormat: "Output Format",
+      edgeSmoothing: "Edge Smoothing",
+      edgeSmoothingOff: "Off",
+      edgeSmoothingLight: "Light",
+      edgeSmoothingMedium: "Medium",
+      edgeSmoothingStrong: "Strong",
+      colorDecontamination: "Color Decontamination",
       rendering: "Renderizando...",
       submit: "Remover fundo",
       submitBatch: "Remover fundo ({count} arquivos)",

packages/shared/src/i18n/ru.ts

@@ -594,6 +594,13 @@ export const ru: TranslationKeys = {
       intensity: "Интенсивность",
       addShadow: "Добавить тень",
       opacity: "Непрозрачность",
+      outputFormat: "Output Format",
+      edgeSmoothing: "Edge Smoothing",
+      edgeSmoothingOff: "Off",
+      edgeSmoothingLight: "Light",
+      edgeSmoothingMedium: "Medium",
+      edgeSmoothingStrong: "Strong",
+      colorDecontamination: "Color Decontamination",
       rendering: "Рендеринг...",
       submit: "Удалить фон",
       submitBatch: "Удалить фон ({count} файлов)",

packages/shared/src/i18n/sv.ts

@@ -591,6 +591,13 @@ export const sv: TranslationKeys = {
       intensity: "Intensitet",
       addShadow: "Lagg till skugga",
       opacity: "Opacitet",
+      outputFormat: "Output Format",
+      edgeSmoothing: "Edge Smoothing",
+      edgeSmoothingOff: "Off",
+      edgeSmoothingLight: "Light",
+      edgeSmoothingMedium: "Medium",
+      edgeSmoothingStrong: "Strong",
+      colorDecontamination: "Color Decontamination",
       rendering: "Renderar...",
       submit: "Ta bort bakgrund",
       submitBatch: "Ta bort bakgrund ({count} filer)",

packages/shared/src/i18n/th.ts

@@ -583,6 +583,13 @@ export const th: TranslationKeys = {
       intensity: "ความเข้ม",
       addShadow: "เพิ่มเงา",
       opacity: "ความทึบ",
+      outputFormat: "Output Format",
+      edgeSmoothing: "Edge Smoothing",
+      edgeSmoothingOff: "Off",
+      edgeSmoothingLight: "Light",
+      edgeSmoothingMedium: "Medium",
+      edgeSmoothingStrong: "Strong",
+      colorDecontamination: "Color Decontamination",
       rendering: "กำลังเรนเดอร์...",
       submit: "ลบพื้นหลัง",
       submitBatch: "ลบพื้นหลัง ({count} ไฟล์)",

packages/shared/src/i18n/tr.ts

@@ -595,6 +595,13 @@ export const tr: TranslationKeys = {
       intensity: "Yoğunluk",
       addShadow: "Gölge Ekle",
       opacity: "Opaklık",
+      outputFormat: "Output Format",
+      edgeSmoothing: "Edge Smoothing",
+      edgeSmoothingOff: "Off",
+      edgeSmoothingLight: "Light",
+      edgeSmoothingMedium: "Medium",
+      edgeSmoothingStrong: "Strong",
+      colorDecontamination: "Color Decontamination",
       rendering: "İşleniyor...",
       submit: "Arka Planı Kaldır",
       submitBatch: "Arka Planı Kaldır ({count} dosya)",

packages/shared/src/i18n/uk.ts

@@ -594,6 +594,13 @@ export const uk: TranslationKeys = {
       intensity: "Інтенсивність",
       addShadow: "Додати тінь",
       opacity: "Непрозорість",
+      outputFormat: "Output Format",
+      edgeSmoothing: "Edge Smoothing",
+      edgeSmoothingOff: "Off",
+      edgeSmoothingLight: "Light",
+      edgeSmoothingMedium: "Medium",
+      edgeSmoothingStrong: "Strong",
+      colorDecontamination: "Color Decontamination",
       rendering: "Рендеринг...",
       submit: "Видалити фон",
       submitBatch: "Видалити фон ({count} файлів)",

packages/shared/src/i18n/vi.ts

@@ -594,6 +594,13 @@ export const vi: TranslationKeys = {
       intensity: "Cường độ",
       addShadow: "Thêm bóng đổ",
       opacity: "Độ mờ",
+      outputFormat: "Output Format",
+      edgeSmoothing: "Edge Smoothing",
+      edgeSmoothingOff: "Off",
+      edgeSmoothingLight: "Light",
+      edgeSmoothingMedium: "Medium",
+      edgeSmoothingStrong: "Strong",
+      colorDecontamination: "Color Decontamination",
       rendering: "Đang kết xuất...",
       submit: "Xóa nền",
       submitBatch: "Xóa nền ({count} tệp)",

packages/shared/src/i18n/zh-CN.ts

@@ -537,6 +537,13 @@ export const zhCN: TranslationKeys = {
       intensity: "强度",
       addShadow: "添加阴影",
       opacity: "不透明度",
+      outputFormat: "Output Format",
+      edgeSmoothing: "Edge Smoothing",
+      edgeSmoothingOff: "Off",
+      edgeSmoothingLight: "Light",
+      edgeSmoothingMedium: "Medium",
+      edgeSmoothingStrong: "Strong",
+      colorDecontamination: "Color Decontamination",
       rendering: "渲染中...",
       submit: "移除背景",
       submitBatch: "移除背景（{count} 个文件）",

packages/shared/src/i18n/zh-TW.ts

@@ -536,6 +536,13 @@ export const zhTW: TranslationKeys = {
       intensity: "強度",
       addShadow: "加入陰影",
       opacity: "不透明度",
+      outputFormat: "Output Format",
+      edgeSmoothing: "Edge Smoothing",
+      edgeSmoothingOff: "Off",
+      edgeSmoothingLight: "Light",
+      edgeSmoothingMedium: "Medium",
+      edgeSmoothingStrong: "Strong",
+      colorDecontamination: "Color Decontamination",
       rendering: "算繪中...",
       submit: "移除背景",
       submitBatch: "移除背景（{count}個檔案）",

tests/integration/remove-background.test.ts

@@ -387,6 +387,102 @@ describe("Remove Background", () => {
     }
   });
 
+  it("accepts edge refinement and decontamination settings", async () => {
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "test.png", contentType: "image/png", content: PNG },
+      {
+        name: "settings",
+        content: JSON.stringify({ edgeRefine: 2, decontaminate: true }),
+      },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/remove-background",
+      headers: {
+        authorization: `Bearer ${adminToken}`,
+        "content-type": contentType,
+      },
+      body,
+    });
+
+    expect([202, 501]).toContain(res.statusCode);
+  }, 60_000);
+
+  it("accepts output format settings", async () => {
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "test.png", contentType: "image/png", content: PNG },
+      {
+        name: "settings",
+        content: JSON.stringify({ outputFormat: "webp" }),
+      },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/remove-background",
+      headers: {
+        authorization: `Bearer ${adminToken}`,
+        "content-type": contentType,
+      },
+      body,
+    });
+
+    expect([202, 501]).toContain(res.statusCode);
+  }, 60_000);
+
+  it("rejects edgeRefine out of range", async () => {
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "test.png", contentType: "image/png", content: PNG },
+      {
+        name: "settings",
+        content: JSON.stringify({ edgeRefine: 5 }),
+      },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/remove-background",
+      headers: {
+        authorization: `Bearer ${adminToken}`,
+        "content-type": contentType,
+      },
+      body,
+    });
+
+    expect([400, 501]).toContain(res.statusCode);
+    if (res.statusCode === 400) {
+      const result = JSON.parse(res.body);
+      expect(result.error).toMatch(/invalid settings/i);
+    }
+  });
+
+  it("rejects invalid output format", async () => {
+    const { body, contentType } = createMultipartPayload([
+      { name: "file", filename: "test.png", contentType: "image/png", content: PNG },
+      {
+        name: "settings",
+        content: JSON.stringify({ outputFormat: "gif" }),
+      },
+    ]);
+
+    const res = await app.inject({
+      method: "POST",
+      url: "/api/v1/tools/remove-background",
+      headers: {
+        authorization: `Bearer ${adminToken}`,
+        "content-type": contentType,
+      },
+      body,
+    });
+
+    expect([400, 501]).toContain(res.statusCode);
+    if (res.statusCode === 400) {
+      const result = JSON.parse(res.body);
+      expect(result.error).toMatch(/invalid settings/i);
+    }
+  });
+
   it("rejects unauthenticated requests", async () => {
     const { body, contentType } = createMultipartPayload([
       { name: "file", filename: "test.png", contentType: "image/png", content: PNG },

tests/unit/ai/background-removal.test.ts

@@ -97,6 +97,35 @@ describe("removeBackground", () => {
       });
     });
 
+    it("serializes edgeRefine option into the args JSON", async () => {
+      await removeBackground(FAKE_INPUT, FAKE_OUTPUT_DIR, { edgeRefine: 2 });
+
+      const args = vi.mocked(runPythonWithProgress).mock.calls[0][1];
+      expect(JSON.parse(args[2])).toEqual({ edgeRefine: 2 });
+    });
+
+    it("serializes decontaminate option into the args JSON", async () => {
+      await removeBackground(FAKE_INPUT, FAKE_OUTPUT_DIR, { decontaminate: true });
+
+      const args = vi.mocked(runPythonWithProgress).mock.calls[0][1];
+      expect(JSON.parse(args[2])).toEqual({ decontaminate: true });
+    });
+
+    it("serializes all post-processing options together", async () => {
+      await removeBackground(FAKE_INPUT, FAKE_OUTPUT_DIR, {
+        model: "birefnet-matting",
+        edgeRefine: 1,
+        decontaminate: true,
+      });
+
+      const args = vi.mocked(runPythonWithProgress).mock.calls[0][1];
+      expect(JSON.parse(args[2])).toEqual({
+        model: "birefnet-matting",
+        edgeRefine: 1,
+        decontaminate: true,
+      });
+    });
+
     it("converts input to PNG via sharp before writing to disk", async () => {
       await removeBackground(FAKE_INPUT, FAKE_OUTPUT_DIR);