feat: optimize compression and production deployment

2026-07-25 11:20:45 +08:00
parent 9d7668bdee
commit 0ff9eae56d
15 changed files with 882 additions and 771 deletions
--- a/.dockerignore
+++ b/.dockerignore
@@ -1,5 +1,7 @@
 .git
 .env
+.env.*
+.bench
 target
 uploads
 frontend/node_modules
--- a/.gitignore
+++ b/.gitignore
@@ -7,6 +7,7 @@
 /uploads
 /static
 /logs
+/.bench

 /frontend/node_modules
 /frontend/dist
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -982,7 +982,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "39cab71617ae0d63f51a36d69f866391735b51691dbda63cf6f96d042b63efeb"
 dependencies = [
 "libc",
- "windows-sys 0.52.0",
+ "windows-sys 0.61.2",
 ]

 [[package]]
@@ -1642,6 +1642,7 @@ dependencies = [
 "hmac",
 "image",
 "img-parts",
+ "jpeg-encoder",
 "jsonwebtoken",
 "lettre",
 "oxipng",
@@ -1762,6 +1763,12 @@ dependencies = [
 "libc",
 ]

+[[package]]
+name = "jpeg-encoder"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b0b36cbb4e6704f12f5b5d7b01dac593982c6550859ebd5a66fb15c9ea27fd5"
+
 [[package]]
 name = "js-sys"
 version = "0.3.83"
@@ -2130,7 +2137,7 @@ version = "0.50.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7957b9740744892f114936ab4a57b3f487491bbeafaf8083688b16841a4240e5"
 dependencies = [
- "windows-sys 0.59.0",
+ "windows-sys 0.61.2",
 ]

 [[package]]
@@ -2553,7 +2560,7 @@ dependencies = [
 "once_cell",
 "socket2 0.6.1",
 "tracing",
- "windows-sys 0.52.0",
+ "windows-sys 0.60.2",
 ]

 [[package]]
@@ -2870,7 +2877,7 @@ dependencies = [
 "errno",
 "libc",
 "linux-raw-sys",
- "windows-sys 0.52.0",
+ "windows-sys 0.61.2",
 ]

 [[package]]
@@ -3550,7 +3557,7 @@ dependencies = [
 "getrandom 0.3.4",
 "once_cell",
 "rustix",
- "windows-sys 0.52.0",
+ "windows-sys 0.61.2",
 ]

 [[package]]
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -42,6 +42,7 @@ aes-gcm = "0.10"
 # Keep image-rs limited to formats exposed by the API. AVIF decoding uses
 # libdav1d on Linux; encoding is handled by the direct ravif dependency.
 image = { version = "0.25", default-features = false, features = ["bmp", "gif", "ico", "jpeg", "png", "tiff", "webp"] }
+jpeg-encoder = "0.7"
 oxipng = "9"
 ravif = { version = "0.11", default-features = false, features = ["threading"] }
 webp = { version = "0.3", default-features = false }
--- a/README.md
+++ b/README.md
@@ -8,7 +8,7 @@

 - **图片压缩**：支持 PNG/JPG/JPEG/WebP/AVIF/GIF/BMP/TIFF/ICO（GIF 仅静态，支持格式转换）
 - **批量处理**：支持多图片同时上传和处理
- **压缩率**：1-100（数值越小压缩越强，100 为不压缩）
+- **压缩率**：1-100（JPEG/WebP/AVIF 以该比例为体积上限；无损格式按安全方式尽力优化）
 - **用户系统**：注册、登录、API Key 管理
 - **计费与用量**：套餐/订阅/配额/发票
 - **管理员后台**：用户管理、系统监控、配置管理
@@ -84,7 +84,7 @@ imageforge/
 - Rust（建议使用最新 stable；当前依赖链要求较新的 Rust，建议 `>= 1.85`）
 - PostgreSQL 16+
 - Redis 7+
- Node.js 20+（前端构建）
+- Node.js 22+（前端构建）

 ### 本地开发

@@ -107,10 +107,14 @@ cd frontend && npm run dev
 ### Docker 部署

 ```bash
-# 该 compose 仅包含 postgres/redis，服务本体请按 docs/deployment.md 构建运行
-docker compose -f docker/docker-compose.dev.yml up -d
+cp docker/.env.production.example .env.production
+# 修改全部密钥与 PUBLIC_BASE_URL 后启动完整生产栈
+docker compose --env-file .env.production -f docker/docker-compose.prod.yml up -d --build
+curl --fail http://127.0.0.1:8080/health
 ```

+详细配置、更新、备份与真实图片质量回归见 [部署指南](./docs/deployment.md)。
+
 ## 文档索引

 - [开工前确认清单](./docs/confirm.md)
--- a/docker/.env.production.example
+++ b/docker/.env.production.example
@@ -0,0 +1,45 @@
+# Image tag built by docker/docker-compose.prod.yml
+IMAGEFORGE_TAG=local
+
+# Public listener and URL
+IMAGEFORGE_BIND_ADDRESS=0.0.0.0
+IMAGEFORGE_PORT=8080
+PUBLIC_BASE_URL=http://192.0.2.10:8080
+
+# Replace every secret before starting the stack.
+POSTGRES_PASSWORD=replace-with-a-long-random-password
+JWT_SECRET=replace-with-at-least-32-random-bytes
+API_KEY_PEPPER=replace-with-an-independent-random-secret
+
+# Initial administrator created on first startup.
+ADMIN_EMAIL=admin@example.com
+ADMIN_USERNAME=admin
+ADMIN_PASSWORD=replace-with-a-strong-admin-password
+
+# A four-core host should start with two image jobs per process.
+DATABASE_MAX_CONNECTIONS=10
+WORKER_CONCURRENCY=2
+IMAGE_PROCESSING_CONCURRENCY=2
+
+ALLOW_ANONYMOUS_UPLOAD=true
+ANON_MAX_FILE_SIZE_MB=5
+ANON_MAX_FILES_PER_BATCH=5
+ANON_DAILY_UNITS=10
+ANON_RETENTION_HOURS=24
+MAX_IMAGE_PIXELS=40000000
+IDEMPOTENCY_TTL_HOURS=24
+
+# Enable only when the API port is reachable exclusively through a trusted proxy.
+TRUST_PROXY_HEADERS=false
+MAIL_ENABLED=false
+MAIL_LOG_LINKS_WHEN_DISABLED=false
+# STRIPE_SECRET_KEY=sk_live_replace_me
+# STRIPE_WEBHOOK_SECRET=whsec_replace_me
+# MAIL_PROVIDER=custom
+# MAIL_FROM=noreply@example.com
+# MAIL_PASSWORD=replace-with-smtp-authorization-code
+# MAIL_FROM_NAME=ImageForge
+# MAIL_SMTP_HOST=smtp.example.com
+# MAIL_SMTP_PORT=465
+# MAIL_SMTP_ENCRYPTION=ssl
+RUST_LOG=info,tower_http=info,imageforge=info
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -1,4 +1,6 @@
-FROM rust:1.92-bookworm AS builder
+# syntax=docker/dockerfile:1.7
+
+FROM rust:1.92-trixie AS builder

 WORKDIR /app

@@ -14,35 +16,45 @@ COPY src ./src
 COPY migrations ./migrations
 COPY templates ./templates

-RUN cargo build --release
+RUN --mount=type=cache,target=/usr/local/cargo/registry,sharing=locked \
+    --mount=type=cache,target=/app/target,sharing=locked \
+    cargo build --release --locked \
+  && cp /app/target/release/imageforge /app/imageforge

-FROM node:20-alpine AS frontend-builder
+FROM node:22-alpine AS frontend-builder

 WORKDIR /app/frontend
 COPY frontend/package*.json ./
-RUN npm ci
+RUN --mount=type=cache,target=/root/.npm,sharing=locked npm ci
 COPY frontend ./
 RUN npm run build

-FROM debian:bookworm-slim
+FROM debian:trixie-slim

 RUN apt-get update && apt-get install -y --no-install-recommends \
    ca-certificates \
-    libdav1d6 \
+    curl \
+    libdav1d7 \
  && rm -rf /var/lib/apt/lists/*

+RUN groupadd --system --gid 10001 imageforge \
+  && useradd --system --uid 10001 --gid imageforge --home-dir /app --shell /usr/sbin/nologin imageforge
+
 WORKDIR /app

-COPY --from=builder /app/target/release/imageforge ./imageforge
+COPY --from=builder /app/imageforge ./imageforge
 COPY --from=frontend-builder /app/frontend/dist ./static
 COPY migrations ./migrations

-RUN mkdir -p uploads
+RUN mkdir -p uploads \
+  && chown imageforge:imageforge uploads

 ENV HOST=0.0.0.0
 ENV PORT=8080

 EXPOSE 8080

+USER 10001:10001
+
 CMD ["./imageforge"]

--- a/docker/docker-compose.prod.yml
+++ b/docker/docker-compose.prod.yml
@@ -0,0 +1,128 @@
+name: imageforge
+
+x-imageforge-environment: &imageforge-environment
+  DATABASE_URL: postgres://imageforge:${POSTGRES_PASSWORD:?POSTGRES_PASSWORD is required}@postgres:5432/imageforge
+  DATABASE_MAX_CONNECTIONS: ${DATABASE_MAX_CONNECTIONS:-10}
+  REDIS_URL: redis://redis:6379
+  JWT_SECRET: ${JWT_SECRET:?JWT_SECRET is required}
+  JWT_EXPIRY_HOURS: ${JWT_EXPIRY_HOURS:-168}
+  API_KEY_PEPPER: ${API_KEY_PEPPER:?API_KEY_PEPPER is required}
+  BILLING_PROVIDER: ${BILLING_PROVIDER:-stripe}
+  STORAGE_TYPE: local
+  STORAGE_PATH: /app/uploads
+  PUBLIC_BASE_URL: ${PUBLIC_BASE_URL:-http://localhost:8080}
+  WORKER_CONCURRENCY: ${WORKER_CONCURRENCY:-2}
+  IMAGE_PROCESSING_CONCURRENCY: ${IMAGE_PROCESSING_CONCURRENCY:-2}
+  ALLOW_ANONYMOUS_UPLOAD: ${ALLOW_ANONYMOUS_UPLOAD:-true}
+  ANON_MAX_FILE_SIZE_MB: ${ANON_MAX_FILE_SIZE_MB:-5}
+  ANON_MAX_FILES_PER_BATCH: ${ANON_MAX_FILES_PER_BATCH:-5}
+  ANON_DAILY_UNITS: ${ANON_DAILY_UNITS:-10}
+  ANON_RETENTION_HOURS: ${ANON_RETENTION_HOURS:-24}
+  MAX_IMAGE_PIXELS: ${MAX_IMAGE_PIXELS:-40000000}
+  IDEMPOTENCY_TTL_HOURS: ${IDEMPOTENCY_TTL_HOURS:-24}
+  TRUST_PROXY_HEADERS: ${TRUST_PROXY_HEADERS:-false}
+  RUST_LOG: ${RUST_LOG:-info,tower_http=info,imageforge=info}
+
+services:
+  postgres:
+    image: postgres:16-alpine
+    environment:
+      POSTGRES_DB: imageforge
+      POSTGRES_USER: imageforge
+      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD}
+    volumes:
+      - postgres_data:/var/lib/postgresql/data
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U imageforge -d imageforge"]
+      interval: 5s
+      timeout: 3s
+      retries: 20
+    restart: unless-stopped
+
+  redis:
+    image: redis:7-alpine
+    command: ["redis-server", "--appendonly", "yes", "--maxmemory-policy", "noeviction"]
+    volumes:
+      - redis_data:/data
+    healthcheck:
+      test: ["CMD", "redis-cli", "ping"]
+      interval: 5s
+      timeout: 3s
+      retries: 20
+    restart: unless-stopped
+
+  api:
+    image: imageforge:${IMAGEFORGE_TAG:-local}
+    build:
+      context: ..
+      dockerfile: docker/Dockerfile
+    init: true
+    environment:
+      <<: *imageforge-environment
+      IMAGEFORGE_ROLE: api
+      ADMIN_EMAIL: ${ADMIN_EMAIL:-}
+      ADMIN_USERNAME: ${ADMIN_USERNAME:-}
+      ADMIN_PASSWORD: ${ADMIN_PASSWORD:-}
+      STRIPE_SECRET_KEY: "${STRIPE_SECRET_KEY:-}"
+      STRIPE_WEBHOOK_SECRET: "${STRIPE_WEBHOOK_SECRET:-}"
+      MAIL_ENABLED: ${MAIL_ENABLED:-false}
+      MAIL_LOG_LINKS_WHEN_DISABLED: ${MAIL_LOG_LINKS_WHEN_DISABLED:-false}
+      MAIL_PROVIDER: ${MAIL_PROVIDER:-qq}
+      MAIL_FROM: ${MAIL_FROM:-noreply@example.com}
+      MAIL_PASSWORD: "${MAIL_PASSWORD:-}"
+      MAIL_FROM_NAME: ${MAIL_FROM_NAME:-ImageForge}
+      MAIL_SMTP_HOST: "${MAIL_SMTP_HOST:-}"
+      MAIL_SMTP_PORT: "${MAIL_SMTP_PORT:-}"
+      MAIL_SMTP_ENCRYPTION: "${MAIL_SMTP_ENCRYPTION:-}"
+    ports:
+      - "${IMAGEFORGE_BIND_ADDRESS:-0.0.0.0}:${IMAGEFORGE_PORT:-8080}:8080"
+    volumes:
+      - uploads:/app/uploads
+    tmpfs:
+      - /tmp:size=256m,mode=1777
+    depends_on:
+      postgres:
+        condition: service_healthy
+      redis:
+        condition: service_healthy
+    healthcheck:
+      test: ["CMD", "curl", "--fail", "--silent", "http://127.0.0.1:8080/health"]
+      interval: 10s
+      timeout: 3s
+      retries: 12
+      start_period: 20s
+    security_opt:
+      - no-new-privileges:true
+    cap_drop:
+      - ALL
+    read_only: true
+    restart: unless-stopped
+
+  worker:
+    image: imageforge:${IMAGEFORGE_TAG:-local}
+    init: true
+    environment:
+      <<: *imageforge-environment
+      IMAGEFORGE_ROLE: worker
+    volumes:
+      - uploads:/app/uploads
+    tmpfs:
+      - /tmp:size=256m,mode=1777
+    depends_on:
+      postgres:
+        condition: service_healthy
+      redis:
+        condition: service_healthy
+      api:
+        condition: service_healthy
+    security_opt:
+      - no-new-privileges:true
+    cap_drop:
+      - ALL
+    read_only: true
+    restart: unless-stopped
+
+volumes:
+  postgres_data:
+  redis_data:
+  uploads:
--- a/docs/api.md
+++ b/docs/api.md
@@ -272,9 +272,9 @@ Idempotency-Key: <key>          # 建议
 | 字段 | 类型 | 必填 | 说明 |
 |---|---|---:|---|
 | `file` | File | 是 | 图片文件 |
-| `compression_rate` | Integer | 否 | 压缩率 1-100（压缩后体积占原图比例，数值越小压缩越强，100 表示不压缩），优先级高于 `level` |
+| `compression_rate` | Integer | 否 | 压缩率 1-100；JPEG/WebP/AVIF 以该比例为体积上限，无损格式为尽力优化，100 表示不压缩；优先级高于 `level` |
 | `level` | String | 否 | `high` / `medium` / `low`（兼容参数，默认 `medium`） |
-| `output_format` | String | 否 | 输出格式：`png/jpeg/webp/avif/gif/bmp/tiff/ico`（默认保持原格式） |
+| `output_format` | String | 否 | 输出格式：`png/jpeg/webp/avif/gif/bmp/tiff/ico`（默认保持原格式；ICO 自动等比缩至 256x256 边界） |
 | `max_width` | Integer | 否 | 最大宽度（等比缩放） |
 | `max_height` | Integer | 否 | 最大高度（等比缩放） |
 | `target_size_bytes` | Integer | 否 | 目标体积（字节），仅 `jpeg/webp/avif` 输出支持；会优先保清晰度并在必要时小幅缩放 |
@@ -340,7 +340,7 @@ Idempotency-Key: <key>           # 建议
 | 字段 | 类型 | 必填 | 说明 |
 |---|---|---:|---|
 | `files[]` | File[] | 是 | 图片文件数组（上限由套餐决定） |
-| `compression_rate` | Integer | 否 | 压缩率 1-100（压缩后体积占原图比例，数值越小压缩越强，100 表示不压缩），优先级高于 `level` |
+| `compression_rate` | Integer | 否 | 压缩率 1-100；JPEG/WebP/AVIF 以该比例为体积上限，无损格式为尽力优化，100 表示不压缩；优先级高于 `level` |
 | `level` | String | 否 | `high` / `medium` / `low`（兼容参数） |
 | `output_format` | String | 否 | 输出格式：`png/jpeg/webp/avif/gif/bmp/tiff/ico`（默认保持原格式） |
 | `preserve_metadata` | Boolean | 否 | 是否保留元数据（默认 `false`） |
--- a/docs/deployment.md
+++ b/docs/deployment.md
@@ -1,714 +1,155 @@
 # 部署指南

-## 环境准备
-
-### 系统要求
-
- Linux (Ubuntu 22.04+ / Debian 12+ 推荐)
- 2+ CPU 核心（启用独立 Worker 建议 4+）
- 4GB+ 内存
- 50GB+ 磁盘空间
-
-### 依赖安装
-
-```bash
-# Ubuntu/Debian
-sudo apt update
-sudo apt install -y \
-    build-essential \
-    pkg-config \
-    libssl-dev \
-    libpq-dev \
-    cmake \
-    libdav1d-dev \
-    nasm \
-    libjpeg-dev \
-    libpng-dev \
-    libwebp-dev
-
-# 安装 Rust
-curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
-source ~/.cargo/env
-
-# 初始化数据库会用到 psql（建议安装 PostgreSQL client）
-sudo apt install -y postgresql-client
-
-# 安装 Node.js (前端构建)
-curl -fsSL https://deb.nodesource.com/setup_20.x | sudo -E bash -
-sudo apt install -y nodejs
-```
-
---
-
-## 本地开发
-
-### 1. 启动数据库服务
-
-```bash
-# 使用 Docker Compose 启动 PostgreSQL 和 Redis
-docker-compose -f docker/docker-compose.dev.yml up -d
-```
-
-`docker/docker-compose.dev.yml`:
-```yaml
-version: '3.8'
-
-services:
-  postgres:
-    image: postgres:16-alpine
-    environment:
-      POSTGRES_USER: imageforge
-      POSTGRES_PASSWORD: devpassword
-      POSTGRES_DB: imageforge
-    ports:
-      - "5432:5432"
-    volumes:
-      - postgres_data:/var/lib/postgresql/data
-
-  redis:
-    image: redis:7-alpine
-    ports:
-      - "6379:6379"
-    volumes:
-      - redis_data:/data
-
-  # 规划：接入 S3 存储后可增加 MinIO；当前版本仅支持本地存储
-  # minio:
-  #   image: minio/minio:RELEASE.2024-01-28T20-20-01Z
-  #   command: server /data --console-address ":9001"
-  #   environment:
-  #     MINIO_ROOT_USER: minioadmin
-  #     MINIO_ROOT_PASSWORD: minioadmin
-  #   ports:
-  #     - "9000:9000"
-  #     - "9001:9001"
-  #   volumes:
-  #     - minio_data:/data
-
-volumes:
-  postgres_data:
-  redis_data:
-  minio_data:
-```
-
-### 2. 配置环境变量
-
-```bash
-cp .env.example .env
-```
-
-`.env.example`:
-```bash
-# 运行模式：建议将 API 与 Worker 分开运行
-IMAGEFORGE_ROLE=api # api | worker
-
-# 服务配置
-HOST=0.0.0.0
-PORT=8080
-PUBLIC_BASE_URL=http://localhost:8080
-RUST_LOG=info,imageforge=debug
-
-# 数据库
-DATABASE_URL=postgres://imageforge:devpassword@localhost:5432/imageforge
-
-# Redis
-REDIS_URL=redis://localhost:6379
-
-# Worker 并发（每个批量任务内同时处理的文件数）
-WORKER_CONCURRENCY=4
-
-# 图片处理全局并发（每个 API/Worker 进程）
-IMAGE_PROCESSING_CONCURRENCY=4
-
-# 仅在后端端口不对公网开放、请求必经可信代理时启用
-TRUST_PROXY_HEADERS=false
-
-# JWT（网站/管理后台）
-JWT_SECRET=your-super-secret-key-change-in-production
-JWT_EXPIRY_HOURS=168
-
-# API Key
-API_KEY_PEPPER=please-change-this-in-production
-
-# 存储（当前实现仅支持 local）
-STORAGE_TYPE=local
-STORAGE_PATH=./uploads
-
-# 计费（已确认：Stripe）
-BILLING_PROVIDER=stripe
-STRIPE_SECRET_KEY=sk_test_xxx
-STRIPE_WEBHOOK_SECRET=whsec_xxx
-
-# 限制（默认值；最终以套餐/用户覆盖为准）
-ALLOW_ANONYMOUS_UPLOAD=true
-ANON_MAX_FILE_SIZE_MB=5
-ANON_MAX_FILES_PER_BATCH=5
-ANON_DAILY_UNITS=10
-MAX_IMAGE_PIXELS=40000000
-IDEMPOTENCY_TTL_HOURS=24
-
-# 结果保留（匿名默认；登录用户按套餐 retention_days）
-ANON_RETENTION_HOURS=24
-
-# 管理员初始账户
-ADMIN_EMAIL=admin@example.com
-ADMIN_PASSWORD=changeme123
-```
-
-### 3. 初始化数据库
-
-API 或 Worker 启动时会通过 SQLx 自动、顺序执行 `migrations/` 下尚未应用的迁移。迁移失败时进程会退出，不会在不完整的数据库结构上继续提供服务。
-
-### 4. 启动开发服务器
-
-```bash
-# 后端 API (热重载)
-cargo install cargo-watch
-IMAGEFORGE_ROLE=api cargo watch -x run
-
-# 后端 Worker（另一个终端，处理异步/批量任务）
-IMAGEFORGE_ROLE=worker cargo watch -x run
-
-# 前端 (另一个终端)
-cd frontend
-npm install
-npm run dev
-```
-
-### 5. Stripe Webhook 本地调试（可选）
-
-本地调试 Stripe 订阅/支付状态，通常需要将 Stripe Webhook 转发到本机：
-
-```bash
-# 1) 安装并登录 Stripe CLI（按官方文档）
-# 2) 监听并转发到你的后端回调地址
-stripe listen --forward-to http://localhost:8080/api/v1/webhooks/stripe
-
-# CLI 会输出一个 whsec_...，写入 .env 的 STRIPE_WEBHOOK_SECRET
-```
-
---
-
 ## 生产部署

-> 注意：以下内容为生产部署模板示例；仓库当前首期仅提供开发用 `docker/docker-compose.dev.yml`，生产 compose/Dockerfile/nginx/k8s 等可在开工阶段按需落地并调整。
+仓库提供完整的 `docker/Dockerfile` 与 `docker/docker-compose.prod.yml`。生产编排包含 API、Worker、PostgreSQL 和 Redis；数据库与 Redis 不发布宿主机端口，API 和 Worker 使用同一上传卷，并以非 root、只读根文件系统运行。

-### 方案一：Docker Compose（推荐小规模）
+### 环境要求

-`docker/docker-compose.prod.yml`:
-```yaml
-version: '3.8'
+- Linux x86_64
+- Docker Engine 26+ 与 Docker Compose 2.20+
+- 最低 2 核 CPU、4GB 内存；启用 AVIF 和独立 Worker 时建议 4 核、8GB 内存
+- 首次构建可访问 Docker Hub 与 crates.io

-services:
-  api:
-    build:
-      context: ..
-      dockerfile: docker/Dockerfile
-    environment:
-      - IMAGEFORGE_ROLE=api
-      - TRUST_PROXY_HEADERS=true
-      - BILLING_PROVIDER=stripe
-      - PUBLIC_BASE_URL=https://your-domain.com
-      - STRIPE_SECRET_KEY=${STRIPE_SECRET_KEY}
-      - STRIPE_WEBHOOK_SECRET=${STRIPE_WEBHOOK_SECRET}
-      - DATABASE_URL=postgres://imageforge:${DB_PASSWORD}@postgres:5432/imageforge
-      - REDIS_URL=redis://redis:6379
-      - JWT_SECRET=${JWT_SECRET}
-      - API_KEY_PEPPER=${API_KEY_PEPPER}
-      - STORAGE_TYPE=local
-      - STORAGE_PATH=/app/uploads
-    expose:
-      - "8080"
-    volumes:
-      - uploads:/app/uploads
-    depends_on:
-      - postgres
-      - redis
-    restart: unless-stopped
+Debian 13、4 核 CPU、8GB 内存的实测起始值为 `WORKER_CONCURRENCY=2` 和 `IMAGE_PROCESSING_CONCURRENCY=2`。AVIF 是 CPU 密集型编码，不要直接把并发设置为 CPU 核数的数倍。

-  worker:
-    build:
-      context: ..
-      dockerfile: docker/Dockerfile
-    environment:
-      - IMAGEFORGE_ROLE=worker
-      - DATABASE_URL=postgres://imageforge:${DB_PASSWORD}@postgres:5432/imageforge
-      - REDIS_URL=redis://redis:6379
-      - JWT_SECRET=${JWT_SECRET}
-      - API_KEY_PEPPER=${API_KEY_PEPPER}
-      - STORAGE_TYPE=local
-      - STORAGE_PATH=/app/uploads
-    volumes:
-      - uploads:/app/uploads
-    depends_on:
-      - postgres
-      - redis
-    restart: unless-stopped
+### 首次启动

-  postgres:
-    image: postgres:16-alpine
-    environment:
-      POSTGRES_USER: imageforge
-      POSTGRES_PASSWORD: ${DB_PASSWORD}
-      POSTGRES_DB: imageforge
-    volumes:
-      - postgres_data:/var/lib/postgresql/data
-    restart: unless-stopped
+```bash
+cp docker/.env.production.example .env.production
+chmod 600 .env.production

-  redis:
-    image: redis:7-alpine
-    volumes:
-      - redis_data:/data
-    restart: unless-stopped
+# 分别生成 POSTGRES_PASSWORD、JWT_SECRET、API_KEY_PEPPER 和管理员密码。
+# hex 不包含数据库 URL 与 .env 需要转义的保留字符。
+openssl rand -hex 32

-  nginx:
-    image: nginx:alpine
-    ports:
-      - "80:80"
-      - "443:443"
-    volumes:
-      - ./nginx.conf:/etc/nginx/nginx.conf:ro
-      - /etc/letsencrypt:/etc/letsencrypt:ro
-    depends_on:
-      - api
-    restart: unless-stopped
+# 编辑公开地址和全部 replace-with-* 值后检查配置。
+docker compose \
+  --env-file .env.production \
+  -f docker/docker-compose.prod.yml \
+  config --quiet

-volumes:
-  uploads:
-  postgres_data:
-  redis_data:
+docker compose \
+  --env-file .env.production \
+  -f docker/docker-compose.prod.yml \
+  up -d --build
 ```

-`docker/Dockerfile`:
-```dockerfile
-FROM rust:1.92-bookworm AS builder
+API 健康后 Worker 才会启动，避免两个进程在首次部署时同时执行迁移。

-WORKDIR /app
-
-RUN apt-get update && apt-get install -y --no-install-recommends \
-    cmake \
-    libdav1d-dev \
-    nasm \
-    pkg-config \
-  && rm -rf /var/lib/apt/lists/*
-
-COPY Cargo.toml Cargo.lock ./
-COPY src ./src
-COPY migrations ./migrations
-COPY templates ./templates
-
-RUN cargo build --release
-
-# 前端构建阶段
-FROM node:20-alpine AS frontend-builder
-
-WORKDIR /app/frontend
-COPY frontend/package*.json ./
-RUN npm ci
-COPY frontend ./
-RUN npm run build
-
-# 运行阶段
-FROM debian:bookworm-slim
-
-RUN apt-get update && apt-get install -y --no-install-recommends \
-    ca-certificates \
-    libdav1d6 \
-  && rm -rf /var/lib/apt/lists/*
-
-WORKDIR /app
-
-COPY --from=builder /app/target/release/imageforge ./imageforge
-COPY --from=frontend-builder /app/frontend/dist ./static
-COPY migrations ./migrations
-
-RUN mkdir -p uploads
-
-ENV HOST=0.0.0.0
-ENV PORT=8080
-
-EXPOSE 8080
-
-CMD ["./imageforge"]
+```bash
+docker compose --env-file .env.production -f docker/docker-compose.prod.yml ps
+curl --fail http://127.0.0.1:8080/health
 ```

-`docker/nginx.conf`:
+预期健康响应：
+
+```json
+{"status":"healthy","database":"connected","redis":"connected"}
+```
+
+### 更新与回滚
+
+更新代码后保留 `.env.production` 和命名卷，重新构建并滚动重建：
+
+```bash
+git pull --ff-only
+docker compose --env-file .env.production -f docker/docker-compose.prod.yml build api
+docker compose --env-file .env.production -f docker/docker-compose.prod.yml up -d
+```
+
+生产镜像应使用不可变的 `IMAGEFORGE_TAG`。回滚时把该值改回上一镜像标签，然后再次运行 `up -d`。
+
+### 反向代理
+
+直接通过服务器地址访问时保持 `TRUST_PROXY_HEADERS=false`。只有当 8080 端口不对客户端开放、所有请求都经过可信反向代理时，才设置为 `true`，并由代理覆盖 `X-Forwarded-For` 与 `X-Forwarded-Proto`。
+
+代理至少需要：
+
 ```nginx
-events {
-    worker_connections 1024;
-}
-
-http {
-    include       mime.types;
-    default_type  application/octet-stream;
-
-    # 日志
-    access_log /var/log/nginx/access.log;
-    error_log /var/log/nginx/error.log;
-
-    # 文件上传大小限制
-    client_max_body_size 100M;
-
-    # Gzip
-    gzip on;
-    gzip_types text/plain text/css application/json application/javascript;
-
-    upstream backend {
-        server api:8080;
-    }
-
-    server {
-        listen 80;
-        server_name your-domain.com;
-        return 301 https://$server_name$request_uri;
-    }
-
-    server {
-        listen 443 ssl http2;
-        server_name your-domain.com;
-
-        ssl_certificate /etc/letsencrypt/live/your-domain.com/fullchain.pem;
-        ssl_certificate_key /etc/letsencrypt/live/your-domain.com/privkey.pem;
-
-        # SSL 配置
-        ssl_protocols TLSv1.2 TLSv1.3;
-        ssl_ciphers ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256;
-        ssl_prefer_server_ciphers off;
-
-        # 静态文件
-        location /static/ {
-            proxy_pass http://backend;
-            expires 30d;
-            add_header Cache-Control "public, immutable";
-        }
-
-        # WebSocket
-        location /ws/ {
-            proxy_pass http://backend;
-            proxy_http_version 1.1;
-            proxy_set_header Upgrade $http_upgrade;
-            proxy_set_header Connection "upgrade";
-            proxy_set_header Host $host;
-            proxy_read_timeout 86400;
-        }
-
-        # API 和其他请求
-        location / {
-            proxy_pass http://backend;
-            proxy_set_header Host $host;
-            proxy_set_header X-Real-IP $remote_addr;
-            proxy_set_header X-Forwarded-For $remote_addr;
-            proxy_set_header X-Forwarded-Proto $scheme;
-        }
-    }
+location / {
+    proxy_pass http://127.0.0.1:8080;
+    proxy_set_header Host $host;
+    proxy_set_header X-Real-IP $remote_addr;
+    proxy_set_header X-Forwarded-For $remote_addr;
+    proxy_set_header X-Forwarded-Proto $scheme;
+    client_max_body_size 100m;
+    proxy_read_timeout 300s;
 }
 ```

-### 部署步骤
+### 日志与备份

 ```bash
-# 1. 创建 .env 文件
-cat > .env << EOF
-DB_PASSWORD=your-secure-db-password
-JWT_SECRET=your-very-long-random-jwt-secret-at-least-32-chars
-STRIPE_SECRET_KEY=sk_live_xxx
-STRIPE_WEBHOOK_SECRET=whsec_xxx
-EOF
+docker compose --env-file .env.production -f docker/docker-compose.prod.yml logs -f api worker

-# 2. 获取 SSL 证书
-sudo certbot certonly --standalone -d your-domain.com
-
-# 3. 构建并启动
-docker-compose -f docker/docker-compose.prod.yml up -d --build
-
-# 4. 查看日志
-docker-compose -f docker/docker-compose.prod.yml logs -f api
+docker compose --env-file .env.production -f docker/docker-compose.prod.yml \
+  exec -T postgres pg_dump -U imageforge imageforge | gzip > imageforge.sql.gz
 ```

---
+除数据库外，还要备份 Compose 的 `uploads` 命名卷。恢复前停止 API 与 Worker，避免数据库记录与文件卷产生时间差。

-### 方案二：Kubernetes（大规模）
-
-`k8s/deployment.yaml`:
-```yaml
-apiVersion: apps/v1
-kind: Deployment
-metadata:
-  name: imageforge
-spec:
-  replicas: 3
-  selector:
-    matchLabels:
-      app: imageforge
-  template:
-    metadata:
-      labels:
-        app: imageforge
-    spec:
-      containers:
-      - name: imageforge
-        image: your-registry/imageforge:latest
-        ports:
-        - containerPort: 8080
-        env:
-        - name: IMAGEFORGE_ROLE
-          value: api
-        - name: DATABASE_URL
-          valueFrom:
-            secretKeyRef:
-              name: imageforge-secrets
-              key: database-url
-        - name: REDIS_URL
-          valueFrom:
-            secretKeyRef:
-              name: imageforge-secrets
-              key: redis-url
-        - name: JWT_SECRET
-          valueFrom:
-            secretKeyRef:
-              name: imageforge-secrets
-              key: jwt-secret
-        resources:
-          requests:
-            memory: "512Mi"
-            cpu: "500m"
-          limits:
-            memory: "2Gi"
-            cpu: "2000m"
-        livenessProbe:
-          httpGet:
-            path: /health
-            port: 8080
-          initialDelaySeconds: 10
-          periodSeconds: 30
-        readinessProbe:
-          httpGet:
-            path: /health
-            port: 8080
-          initialDelaySeconds: 5
-          periodSeconds: 10
---
-apiVersion: v1
-kind: Service
-metadata:
-  name: imageforge
-spec:
-  selector:
-    app: imageforge
-  ports:
-  - port: 80
-    targetPort: 8080
-  type: ClusterIP
---
-apiVersion: networking.k8s.io/v1
-kind: Ingress
-metadata:
-  name: imageforge
-  annotations:
-    kubernetes.io/ingress.class: nginx
-    cert-manager.io/cluster-issuer: letsencrypt-prod
-spec:
-  tls:
-  - hosts:
-    - your-domain.com
-    secretName: imageforge-tls
-  rules:
-  - host: your-domain.com
-    http:
-      paths:
-      - path: /
-        pathType: Prefix
-        backend:
-          service:
-            name: imageforge
-            port:
-              number: 80
-
---
-apiVersion: apps/v1
-kind: Deployment
-metadata:
-  name: imageforge-worker
-spec:
-  replicas: 2
-  selector:
-    matchLabels:
-      app: imageforge-worker
-  template:
-    metadata:
-      labels:
-        app: imageforge-worker
-    spec:
-      containers:
-      - name: imageforge-worker
-        image: your-registry/imageforge:latest
-        env:
-        - name: IMAGEFORGE_ROLE
-          value: worker
-        - name: DATABASE_URL
-          valueFrom:
-            secretKeyRef:
-              name: imageforge-secrets
-              key: database-url
-        - name: REDIS_URL
-          valueFrom:
-            secretKeyRef:
-              name: imageforge-secrets
-              key: redis-url
-        - name: JWT_SECRET
-          valueFrom:
-            secretKeyRef:
-              name: imageforge-secrets
-              key: jwt-secret
-        resources:
-          requests:
-            memory: "512Mi"
-            cpu: "500m"
-          limits:
-            memory: "4Gi"
-            cpu: "4000m"
-```
-
---
-
-## 监控与日志
-
-### Prometheus 指标
-
-应用暴露 `/metrics` 端点：
-
-```rust
-// 在代码中添加指标
-use prometheus::{Counter, Histogram};
-
-lazy_static! {
-    static ref COMPRESSION_REQUESTS: Counter = Counter::new(
-        "imageforge_compression_requests_total",
-        "Total number of compression requests"
-    ).unwrap();
-
-    static ref COMPRESSION_DURATION: Histogram = Histogram::with_opts(
-        HistogramOpts::new(
-            "imageforge_compression_duration_seconds",
-            "Time spent compressing images"
-        )
-    ).unwrap();
-}
-```
-
-### Grafana 仪表板
-
-监控项目：
- 请求量 / QPS
- 响应时间 P50/P95/P99
- 错误率
- 压缩任务队列长度
- CPU / 内存使用率
- 磁盘使用率
-
-### 日志聚合
-
-使用 ELK Stack 或 Loki：
-
-```yaml
-# docker-compose 添加 Loki
-loki:
-  image: grafana/loki:2.9.0
-  ports:
-    - "3100:3100"
-  command: -config.file=/etc/loki/local-config.yaml
-
-promtail:
-  image: grafana/promtail:2.9.0
-  volumes:
-    - /var/log:/var/log
-    - ./promtail-config.yml:/etc/promtail/config.yml
-  command: -config.file=/etc/promtail/config.yml
-```
-
---
-
-## 备份策略
-
-### 数据库备份
+## 本地开发

 ```bash
-#!/bin/bash
-# backup.sh
+cp .env.example .env
+docker compose -f docker/docker-compose.dev.yml up -d

-DATE=$(date +%Y%m%d_%H%M%S)
-BACKUP_DIR=/backups
+# 终端 1
+IMAGEFORGE_ROLE=api cargo run

-# PostgreSQL 备份
-docker exec postgres pg_dump -U imageforge imageforge | gzip > $BACKUP_DIR/db_$DATE.sql.gz
+# 终端 2
+IMAGEFORGE_ROLE=worker cargo run

-# 保留最近 7 天的备份
-find $BACKUP_DIR -name "db_*.sql.gz" -mtime +7 -delete
-
-# 可选：上传到 S3
-# aws s3 cp $BACKUP_DIR/db_$DATE.sql.gz s3://your-bucket/backups/
+# 终端 3
+cd frontend
+npm ci
+npm run dev
 ```

-添加到 crontab：
+API 或 Worker 启动时会通过 SQLx 顺序执行尚未应用的迁移。迁移失败时进程退出，不会在不完整的数据库结构上继续提供服务。
+
+## 压缩质量回归
+
+基准工具会下载固定 Picsum 照片，分别生成 JPEG、PNG、WebP、AVIF 输入，再通过真实 HTTP API 测量目标达标率、格式签名、SSIM、PSNR、分辨率和耗时。
+
 ```bash
-0 3 * * * /path/to/backup.sh
+python3 -m venv .venv-benchmark
+. .venv-benchmark/bin/activate
+pip install -r scripts/requirements-benchmark.txt
+
+python scripts/benchmark_compression.py generate --output-dir .bench/corpus
+
+IMAGEFORGE_BENCH_EMAIL=admin@example.com \
+IMAGEFORGE_BENCH_PASSWORD='replace-me' \
+python scripts/benchmark_compression.py run \
+  --base-url http://127.0.0.1:8080 \
+  --input-dir .bench/corpus \
+  --output-dir .bench/results \
+  --formats jpeg,webp,avif \
+  --rates 30,50,70 \
+  --strict
 ```

-### 上传文件备份
-
-如果使用本地存储，定期同步到 S3：
-```bash
-aws s3 sync /app/uploads s3://your-bucket/uploads --delete
-```
-
---
+`--strict` 会在请求失败、输出格式不匹配或目标体积未达标时返回非零退出码。测试素材与结果位于 `.bench/`，不会提交到 Git。

 ## 故障排查

-### 常见问题
-
-**1. 数据库连接失败**
 ```bash
-# 检查 PostgreSQL 状态
-docker-compose logs postgres
+# 容器与健康状态
+docker compose --env-file .env.production -f docker/docker-compose.prod.yml ps

-# 测试连接
-docker exec -it postgres psql -U imageforge -d imageforge -c "SELECT 1"
-```
+# 最近日志
+docker compose --env-file .env.production -f docker/docker-compose.prod.yml logs --tail=200 api worker

-**2. 压缩失败**
-```bash
-# 检查应用日志
-docker-compose logs api | grep ERROR
-docker-compose logs worker | grep ERROR
+# 数据库迁移状态
+docker compose --env-file .env.production -f docker/docker-compose.prod.yml \
+  exec -T postgres psql -U imageforge -d imageforge \
+  -c 'SELECT version, success FROM _sqlx_migrations ORDER BY version;'

-# 检查磁盘空间
+# 主机资源
+docker stats
 df -h
 ```

-**3. 内存不足**
-```bash
-# 查看内存使用
-docker stats
-
-# 调整容器内存限制
-```
-
-**4. 上传超时**
-```bash
-# 检查 Nginx 配置
-# client_max_body_size 和 proxy_read_timeout
-```
-
-### 健康检查端点
-
-```
-GET /health
-{
-  "status": "healthy",
-  "database": "connected",
-  "redis": "connected",
-  "storage": "available",
-  "uptime": 3600
-}
-```
+若图片压缩长时间排队，先检查 CPU，再下调 `IMAGE_PROCESSING_CONCURRENCY`；若 API 健康但批量任务不推进，检查 Worker 日志和 Redis 状态。
--- a/frontend/src/pages/DocsPage.vue
+++ b/frontend/src/pages/DocsPage.vue
@@ -20,7 +20,7 @@
        <li>Base URL：<code>https://ys.workyai.cn/api/v1</code></li>
        <li>认证方式：<code>X-API-Key</code>（推荐）或 <code>Authorization: Bearer &lt;token&gt;</code></li>
        <li>支持格式：PNG / JPG / JPEG / WebP / AVIF / GIF（静态）/ BMP / TIFF / ICO（支持 output_format 转码）</li>
-        <li>压缩率：<code>compression_rate</code> 1-100，表示压缩后体积占原图比例，100 为不压缩</li>
+        <li>压缩率：<code>compression_rate</code> 1-100；JPEG/WebP/AVIF 以该比例为体积上限，无损格式为尽力优化</li>
        <li>计量：成功压缩 1 个文件计 1 次；若体积未变小或压缩率为 100，则不扣额度</li>
      </ul>
    </div>
--- a/frontend/src/pages/HomePage.vue
+++ b/frontend/src/pages/HomePage.vue
@@ -532,7 +532,9 @@ async function resendVerification() {
                step="1"
                class="w-full"
              />
-              <div class="text-xs text-slate-500">数值越小压缩越强，目标为压缩后体积占原图比例（100% 为不压缩）。</div>
+              <div class="text-xs text-slate-500">
+                数值越小压缩越强；JPEG/WebP/AVIF 会以此为体积上限，无损格式按安全方式优化并显示实际结果。
+              </div>
            </label>

            <!-- 目标大小模式 -->
--- a/scripts/benchmark_compression.py
+++ b/scripts/benchmark_compression.py
@@ -0,0 +1,404 @@
+#!/usr/bin/env python3
+"""Generate a real-photo corpus and benchmark ImageForge through its HTTP API."""
+
+from __future__ import annotations
+
+import argparse
+import csv
+import json
+import math
+import os
+import statistics
+import sys
+import time
+import urllib.error
+import urllib.parse
+import urllib.request
+import uuid
+from datetime import datetime, timezone
+from http.cookiejar import CookieJar
+from pathlib import Path
+from typing import Any
+
+import numpy as np
+from PIL import Image, ImageOps
+
+
+CORPUS = (
+    ("photo_1015_jpeg", 1015, "JPEG", "jpg"),
+    ("photo_1016_png", 1016, "PNG", "png"),
+    ("photo_1025_webp", 1025, "WEBP", "webp"),
+    ("photo_1039_avif", 1039, "AVIF", "avif"),
+)
+FORMAT_EXTENSIONS = {"jpeg": "jpg", "webp": "webp", "avif": "avif"}
+PIL_FORMATS = {"jpeg": "JPEG", "webp": "WEBP", "avif": "AVIF"}
+
+
+def parse_csv_arg(value: str, cast: type = str) -> list[Any]:
+    return [cast(item.strip()) for item in value.split(",") if item.strip()]
+
+
+def open_image(path: Path) -> Image.Image:
+    with Image.open(path) as image:
+        return ImageOps.exif_transpose(image).convert("RGB")
+
+
+def download(url: str) -> bytes:
+    request = urllib.request.Request(url, headers={"User-Agent": "ImageForge benchmark/1.0"})
+    with urllib.request.urlopen(request, timeout=90) as response:
+        return response.read()
+
+
+def generate_corpus(output_dir: Path, width: int, height: int) -> None:
+    output_dir.mkdir(parents=True, exist_ok=True)
+    manifest: list[dict[str, Any]] = []
+
+    for name, image_id, image_format, extension in CORPUS:
+        source_url = f"https://picsum.photos/id/{image_id}/{width}/{height}.jpg"
+        source_bytes = download(source_url)
+        source_path = output_dir / f".{name}.source.jpg"
+        source_path.write_bytes(source_bytes)
+        image = open_image(source_path)
+        source_path.unlink()
+
+        # Normalize dimensions so format and content complexity, not resolution, drive comparisons.
+        image = ImageOps.fit(image, (width, height), method=Image.Resampling.LANCZOS)
+        output_path = output_dir / f"{name}.{extension}"
+        if image_format == "JPEG":
+            image.save(output_path, format=image_format, quality=95, subsampling=0, optimize=True)
+        elif image_format == "PNG":
+            image.save(output_path, format=image_format, optimize=True, compress_level=9)
+        elif image_format == "WEBP":
+            image.save(output_path, format=image_format, lossless=True, method=6)
+        else:
+            image.save(output_path, format=image_format, quality=95, speed=6)
+
+        manifest.append(
+            {
+                "file": output_path.name,
+                "source_url": source_url,
+                "picsum_id": image_id,
+                "format": image_format.lower(),
+                "width": image.width,
+                "height": image.height,
+                "size_bytes": output_path.stat().st_size,
+            }
+        )
+
+    (output_dir / "manifest.json").write_text(
+        json.dumps(manifest, ensure_ascii=False, indent=2) + "\n", encoding="utf-8"
+    )
+    print(f"generated {len(manifest)} images in {output_dir}")
+
+
+def multipart_body(file_path: Path, fields: dict[str, str]) -> tuple[bytes, str]:
+    boundary = f"----imageforge-{uuid.uuid4().hex}"
+    chunks: list[bytes] = []
+    for name, value in fields.items():
+        chunks.extend(
+            (
+                f"--{boundary}\r\n".encode(),
+                f'Content-Disposition: form-data; name="{name}"\r\n\r\n'.encode(),
+                value.encode(),
+                b"\r\n",
+            )
+        )
+
+    chunks.extend(
+        (
+            f"--{boundary}\r\n".encode(),
+            (
+                f'Content-Disposition: form-data; name="file"; '
+                f'filename="{file_path.name}"\r\n'
+            ).encode(),
+            b"Content-Type: application/octet-stream\r\n\r\n",
+            file_path.read_bytes(),
+            b"\r\n",
+            f"--{boundary}--\r\n".encode(),
+        )
+    )
+    return b"".join(chunks), f"multipart/form-data; boundary={boundary}"
+
+
+def request_json(
+    opener: urllib.request.OpenerDirector,
+    url: str,
+    data: bytes,
+    headers: dict[str, str],
+    timeout: int,
+) -> dict[str, Any]:
+    request = urllib.request.Request(url, data=data, headers=headers, method="POST")
+    try:
+        with opener.open(request, timeout=timeout) as response:
+            payload = json.load(response)
+    except urllib.error.HTTPError as error:
+        detail = error.read().decode("utf-8", errors="replace")
+        raise RuntimeError(f"HTTP {error.code}: {detail}") from error
+
+    if not payload.get("success") or "data" not in payload:
+        raise RuntimeError(f"unexpected API response: {payload}")
+    return payload["data"]
+
+
+def login(
+    opener: urllib.request.OpenerDirector,
+    base_url: str,
+    email: str,
+    password: str,
+    timeout: int,
+) -> str:
+    body = json.dumps({"email": email, "password": password}).encode()
+    data = request_json(
+        opener,
+        f"{base_url}/api/v1/auth/login",
+        body,
+        {"Content-Type": "application/json"},
+        timeout,
+    )
+    return str(data["token"])
+
+
+def block_ssim(reference: np.ndarray, candidate: np.ndarray, block: int = 8) -> float:
+    ref = 0.2126 * reference[..., 0] + 0.7152 * reference[..., 1] + 0.0722 * reference[..., 2]
+    out = 0.2126 * candidate[..., 0] + 0.7152 * candidate[..., 1] + 0.0722 * candidate[..., 2]
+    height = (ref.shape[0] // block) * block
+    width = (ref.shape[1] // block) * block
+    if height == 0 or width == 0:
+        height, width, block = ref.shape[0], ref.shape[1], 1
+
+    def blocks(array: np.ndarray) -> np.ndarray:
+        return (
+            array[:height, :width]
+            .reshape(height // block, block, width // block, block)
+            .transpose(0, 2, 1, 3)
+        )
+
+    ref_blocks = blocks(ref)
+    out_blocks = blocks(out)
+    axes = (-1, -2)
+    ref_mean = ref_blocks.mean(axis=axes)
+    out_mean = out_blocks.mean(axis=axes)
+    ref_var = ref_blocks.var(axis=axes)
+    out_var = out_blocks.var(axis=axes)
+    covariance = ((ref_blocks - ref_mean[..., None, None]) * (out_blocks - out_mean[..., None, None])).mean(axis=axes)
+    c1 = (0.01 * 255.0) ** 2
+    c2 = (0.03 * 255.0) ** 2
+    numerator = (2 * ref_mean * out_mean + c1) * (2 * covariance + c2)
+    denominator = (ref_mean**2 + out_mean**2 + c1) * (ref_var + out_var + c2)
+    return float(np.mean(numerator / np.maximum(denominator, 1e-12)))
+
+
+def image_metrics(reference_path: Path, output_path: Path) -> dict[str, Any]:
+    reference = open_image(reference_path)
+    with Image.open(output_path) as opened:
+        detected_format = (opened.format or "unknown").upper()
+        output = ImageOps.exif_transpose(opened).convert("RGB")
+
+    output_width, output_height = output.size
+    if output.size != reference.size:
+        output = output.resize(reference.size, Image.Resampling.LANCZOS)
+
+    ref_array = np.asarray(reference, dtype=np.float64)
+    out_array = np.asarray(output, dtype=np.float64)
+    mse = float(np.mean((ref_array - out_array) ** 2))
+    psnr = 99.0 if mse == 0 else 20.0 * math.log10(255.0 / math.sqrt(mse))
+    return {
+        "detected_format": detected_format,
+        "width": output_width,
+        "height": output_height,
+        "pixel_ratio_pct": output_width * output_height * 100.0 / (reference.width * reference.height),
+        "ssim": block_ssim(ref_array, out_array),
+        "psnr_db": psnr,
+    }
+
+
+def summarize(rows: list[dict[str, Any]]) -> list[dict[str, Any]]:
+    groups: dict[tuple[str, int], list[dict[str, Any]]] = {}
+    for row in rows:
+        if row.get("error"):
+            continue
+        groups.setdefault((str(row["output_format"]), int(row["requested_rate"])), []).append(row)
+
+    summary: list[dict[str, Any]] = []
+    for (output_format, requested_rate), group in sorted(groups.items()):
+        summary.append(
+            {
+                "output_format": output_format,
+                "requested_rate": requested_rate,
+                "cases": len(group),
+                "target_met": sum(bool(row["target_met"]) for row in group),
+                "format_ok": sum(bool(row["format_ok"]) for row in group),
+                "mean_actual_rate_pct": statistics.mean(float(row["actual_rate_pct"]) for row in group),
+                "mean_saved_pct": statistics.mean(float(row["saved_pct"]) for row in group),
+                "mean_ssim": statistics.mean(float(row["ssim"]) for row in group),
+                "mean_psnr_db": statistics.mean(float(row["psnr_db"]) for row in group),
+                "mean_pixel_ratio_pct": statistics.mean(float(row["pixel_ratio_pct"]) for row in group),
+                "median_elapsed_ms": statistics.median(float(row["elapsed_ms"]) for row in group),
+            }
+        )
+    return summary
+
+
+def benchmark(args: argparse.Namespace) -> int:
+    input_dir = Path(args.input_dir)
+    output_dir = Path(args.output_dir)
+    output_dir.mkdir(parents=True, exist_ok=True)
+    inputs = sorted(path for path in input_dir.iterdir() if path.suffix.lower() in {".jpg", ".jpeg", ".png", ".webp", ".avif"})
+    if not inputs:
+        raise RuntimeError(f"no benchmark images found in {input_dir}")
+
+    rates = parse_csv_arg(args.rates, int)
+    formats = [str(value).lower() for value in parse_csv_arg(args.formats)]
+    unsupported = sorted(set(formats) - set(FORMAT_EXTENSIONS))
+    if unsupported:
+        raise RuntimeError(f"unsupported output formats: {', '.join(unsupported)}")
+
+    base_url = args.base_url.rstrip("/")
+    opener = urllib.request.build_opener(urllib.request.HTTPCookieProcessor(CookieJar()))
+    token = args.token or os.getenv("IMAGEFORGE_BENCH_TOKEN", "")
+    if not token:
+        email = args.email or os.getenv("IMAGEFORGE_BENCH_EMAIL", "")
+        password = args.password or os.getenv("IMAGEFORGE_BENCH_PASSWORD", "")
+        if email and password:
+            token = login(opener, base_url, email, password, args.timeout)
+
+    auth_headers = {"Authorization": f"Bearer {token}"} if token else {}
+    rows: list[dict[str, Any]] = []
+    total = len(inputs) * len(formats) * len(rates)
+    case_number = 0
+
+    for input_path in inputs:
+        original_size = input_path.stat().st_size
+        for output_format in formats:
+            for rate in rates:
+                case_number += 1
+                output_path = output_dir / f"{input_path.stem}__{output_format}__r{rate}.{FORMAT_EXTENSIONS[output_format]}"
+                row: dict[str, Any] = {
+                    "input": input_path.name,
+                    "input_format": input_path.suffix.lower().lstrip("."),
+                    "output_format": output_format,
+                    "requested_rate": rate,
+                    "original_size": original_size,
+                }
+                try:
+                    body, content_type = multipart_body(
+                        input_path,
+                        {"compression_rate": str(rate), "output_format": output_format},
+                    )
+                    started = time.perf_counter()
+                    data = request_json(
+                        opener,
+                        f"{base_url}/api/v1/compress",
+                        body,
+                        {**auth_headers, "Content-Type": content_type},
+                        args.timeout,
+                    )
+                    elapsed_ms = (time.perf_counter() - started) * 1000.0
+
+                    download_request = urllib.request.Request(
+                        urllib.parse.urljoin(f"{base_url}/", str(data["download_url"]).lstrip("/")),
+                        headers=auth_headers,
+                    )
+                    with opener.open(download_request, timeout=args.timeout) as response:
+                        output_path.write_bytes(response.read())
+
+                    compressed_size = output_path.stat().st_size
+                    metrics = image_metrics(input_path, output_path)
+                    tolerance_bytes = max(1024, int(original_size * 0.01))
+                    target_bytes = original_size * rate / 100.0
+                    row.update(
+                        {
+                            "compressed_size": compressed_size,
+                            "actual_rate_pct": compressed_size * 100.0 / original_size,
+                            "saved_pct": max(0.0, (original_size - compressed_size) * 100.0 / original_size),
+                            "target_error_pct_points": compressed_size * 100.0 / original_size - rate,
+                            "target_met": compressed_size <= target_bytes + tolerance_bytes,
+                            "format_ok": metrics["detected_format"] == PIL_FORMATS[output_format],
+                            "api_size_matches": int(data["compressed_size"]) == compressed_size,
+                            "elapsed_ms": elapsed_ms,
+                            **metrics,
+                            "error": "",
+                        }
+                    )
+                except Exception as error:  # Continue to expose the full failure matrix.
+                    row["error"] = str(error)
+                rows.append(row)
+                status = "ERROR" if row.get("error") else f"{row['actual_rate_pct']:.1f}% SSIM={row['ssim']:.4f}"
+                print(f"[{case_number:02d}/{total:02d}] {input_path.name} -> {output_format} r{rate}: {status}", flush=True)
+                if args.delay:
+                    time.sleep(args.delay)
+
+    summary = summarize(rows)
+    report = {
+        "generated_at": datetime.now(timezone.utc).isoformat(),
+        "base_url": base_url,
+        "inputs": len(inputs),
+        "cases": len(rows),
+        "errors": sum(bool(row.get("error")) for row in rows),
+        "format_failures": sum(not bool(row.get("format_ok")) for row in rows if not row.get("error")),
+        "target_failures": sum(not bool(row.get("target_met")) for row in rows if not row.get("error")),
+        "summary": summary,
+        "results": rows,
+    }
+    (output_dir / "report.json").write_text(
+        json.dumps(report, ensure_ascii=False, indent=2) + "\n", encoding="utf-8"
+    )
+    fieldnames = sorted({key for row in rows for key in row})
+    with (output_dir / "results.csv").open("w", newline="", encoding="utf-8") as handle:
+        writer = csv.DictWriter(handle, fieldnames=fieldnames)
+        writer.writeheader()
+        writer.writerows(rows)
+
+    print("\nformat rate target format-ok actual% saved% SSIM PSNR pixel% median-ms")
+    for item in summary:
+        print(
+            f"{item['output_format']:>6} {item['requested_rate']:>4} "
+            f"{item['target_met']}/{item['cases']} {item['format_ok']}/{item['cases']} "
+            f"{item['mean_actual_rate_pct']:>7.2f} {item['mean_saved_pct']:>6.2f} "
+            f"{item['mean_ssim']:.4f} {item['mean_psnr_db']:>5.2f} "
+            f"{item['mean_pixel_ratio_pct']:>6.2f} {item['median_elapsed_ms']:>9.1f}"
+        )
+    print(f"\nreport: {output_dir / 'report.json'}")
+    return 1 if args.strict and (report["errors"] or report["format_failures"] or report["target_failures"]) else 0
+
+
+def build_parser() -> argparse.ArgumentParser:
+    parser = argparse.ArgumentParser(description=__doc__)
+    subparsers = parser.add_subparsers(dest="command", required=True)
+
+    generate = subparsers.add_parser("generate", help="download and build the fixed real-photo corpus")
+    generate.add_argument("--output-dir", default=".bench/corpus")
+    generate.add_argument("--width", type=int, default=960)
+    generate.add_argument("--height", type=int, default=640)
+
+    run = subparsers.add_parser("run", help="benchmark a running ImageForge deployment")
+    run.add_argument("--base-url", default="http://127.0.0.1:8080")
+    run.add_argument("--input-dir", default=".bench/corpus")
+    run.add_argument("--output-dir", default=".bench/results")
+    run.add_argument("--formats", default="jpeg,webp,avif")
+    run.add_argument("--rates", default="30,50,70")
+    run.add_argument("--email", default="")
+    run.add_argument("--password", default="")
+    run.add_argument("--token", default="")
+    run.add_argument("--timeout", type=int, default=300)
+    run.add_argument("--delay", type=float, default=0.05)
+    run.add_argument("--strict", action="store_true")
+    return parser
+
+
+def main() -> int:
+    args = build_parser().parse_args()
+    if args.command == "generate":
+        generate_corpus(Path(args.output_dir), args.width, args.height)
+        return 0
+    return benchmark(args)
+
+
+if __name__ == "__main__":
+    try:
+        raise SystemExit(main())
+    except KeyboardInterrupt:
+        raise SystemExit(130) from None
+    except Exception as error:
+        print(f"benchmark failed: {error}", file=sys.stderr)
+        raise SystemExit(1) from error
--- a/scripts/requirements-benchmark.txt
+++ b/scripts/requirements-benchmark.txt
@@ -0,0 +1,2 @@
+numpy>=2,<3
+Pillow>=11,<13
--- a/src/services/compress.rs
+++ b/src/services/compress.rs
@@ -4,7 +4,6 @@ use crate::state::AppState;
 use image::codecs::bmp::BmpEncoder;
 use image::codecs::gif::{GifDecoder, GifEncoder};
 use image::codecs::ico::IcoEncoder;
-use image::codecs::jpeg::JpegEncoder;
 use image::codecs::png::PngEncoder;
 use image::codecs::tiff::TiffEncoder;
 use image::{AnimationDecoder, GenericImageView};
@@ -14,12 +13,13 @@ use oxipng::StripChunks;
 use rgb::FromSlice;
 use std::io::Cursor;

-const TARGET_MIN_DIMENSION: u32 = 640;
+const TARGET_MIN_LONG_EDGE: u32 = 640;
 const TARGET_MIN_SCALE: f64 = 0.55;
 const TARGET_RESIZE_ATTEMPTS: usize = 5;
+const TARGET_SCALE_REFINEMENT_ATTEMPTS: usize = 3;

-const JPEG_TARGET_MIN_QUALITY: u8 = 40;
-const WEBP_TARGET_MIN_QUALITY: u8 = 42;
+const JPEG_TARGET_MIN_QUALITY: u8 = 25;
+const WEBP_TARGET_MIN_QUALITY: u8 = 30;
 const AVIF_TARGET_MIN_QUALITY: u8 = 38;

 #[derive(Debug, Clone, Copy)]
@@ -378,7 +378,7 @@ fn compress_image_bytes_sync(
        output = apply_metadata(output, icc_profile, exif)?;
    }

-    if !resized && output.len() >= input.len() {
+    if format_in == format_out && !resized && output.len() >= input.len() {
        if preserve_metadata {
            return Ok(input);
        }
@@ -475,10 +475,16 @@ fn encode_jpeg_with_quality(image: DynamicImage, quality: u8) -> Result<Vec<u8>,
 }

 fn encode_jpeg_raw(raw: &[u8], w: u32, h: u32, quality: u8) -> Result<Vec<u8>, AppError> {
+    let width = u16::try_from(w)
+        .map_err(|_| AppError::new(ErrorCode::InvalidImage, "JPEG 宽度不能超过 65535 像素"))?;
+    let height = u16::try_from(h)
+        .map_err(|_| AppError::new(ErrorCode::InvalidImage, "JPEG 高度不能超过 65535 像素"))?;
    let mut out = Vec::new();
-    let mut encoder = JpegEncoder::new_with_quality(&mut out, quality);
+    let mut encoder = jpeg_encoder::Encoder::new(&mut out, quality);
+    encoder.set_optimized_huffman_tables(true);
+    encoder.set_progressive(true);
    encoder
-        .encode(raw, w, h, ExtendedColorType::Rgb8)
+        .encode(raw, width, height, jpeg_encoder::ColorType::Rgb)
        .map_err(|err| {
            AppError::new(ErrorCode::CompressionFailed, "JPEG 编码失败").with_source(err)
        })?;
@@ -573,36 +579,33 @@ where
    F: FnMut(&DynamicImage, u8) -> Result<Vec<u8>, AppError>,
 {
    let (orig_w, orig_h) = image.dimensions();
-    let min_w = ((orig_w as f64 * TARGET_MIN_SCALE).round() as u32)
-        .max(TARGET_MIN_DIMENSION.min(orig_w))
-        .max(1);
-    let min_h = ((orig_h as f64 * TARGET_MIN_SCALE).round() as u32)
-        .max(TARGET_MIN_DIMENSION.min(orig_h))
-        .max(1);
+    let long_edge = orig_w.max(orig_h);
+    let long_edge_floor = TARGET_MIN_LONG_EDGE.min(long_edge) as f64 / long_edge as f64;
+    let min_scale = TARGET_MIN_SCALE.max(long_edge_floor).min(1.0);

    let mut scales = Vec::with_capacity(TARGET_RESIZE_ATTEMPTS + 1);
    scales.push(1.0);
    for step in 1..=TARGET_RESIZE_ATTEMPTS {
        let ratio = step as f64 / TARGET_RESIZE_ATTEMPTS as f64;
-        let scale = 1.0 - (1.0 - TARGET_MIN_SCALE) * ratio;
-        scales.push(scale.max(TARGET_MIN_SCALE));
+        scales.push(1.0 - (1.0 - min_scale) * ratio);
    }

-    let mut best_under: Option<(Vec<u8>, u32, u32, u64)> = None;
-    let mut best_over: Option<(Vec<u8>, u32, u32, u64)> = None;
+    let mut best_over: Option<(Vec<u8>, u64, u64)> = None;
+    let mut previous_over_scale = 1.0;
+    let mut last_dimensions: Option<(u32, u32)> = None;

    for scale in scales {
        let new_w = ((orig_w as f64 * scale).round() as u32).clamp(1, orig_w);
        let new_h = ((orig_h as f64 * scale).round() as u32).clamp(1, orig_h);
-
-        if new_w < min_w || new_h < min_h {
+        if last_dimensions == Some((new_w, new_h)) {
            continue;
        }
+        last_dimensions = Some((new_w, new_h));

        let resized = if new_w == orig_w && new_h == orig_h {
            image.clone()
        } else {
-            image.resize(new_w, new_h, image::imageops::FilterType::Lanczos3)
+            image.resize_exact(new_w, new_h, image::imageops::FilterType::Lanczos3)
        };

        let result =
@@ -610,52 +613,69 @@ where
        let result_size = result.len() as u64;

        if result_size <= target_size {
-            let should_update = match &best_under {
-                None => true,
-                Some((_bytes, best_w, best_h, best_size)) => {
-                    let new_pixels = (new_w as u64).saturating_mul(new_h as u64);
-                    let best_pixels = (*best_w as u64).saturating_mul(*best_h as u64);
-                    new_pixels > best_pixels
-                        || (new_pixels == best_pixels && result_size > *best_size)
+            if new_w == orig_w && new_h == orig_h {
+                return Ok(result);
+            }
+
+            // The first passing coarse scale has the highest resolution. Refine the
+            // boundary between it and the preceding failing scale before returning.
+            let mut best_under = result;
+            let mut under_scale = scale;
+            let mut over_scale = previous_over_scale;
+            let mut under_dimensions = (new_w, new_h);
+
+            for _ in 0..TARGET_SCALE_REFINEMENT_ATTEMPTS {
+                let candidate_scale = (under_scale + over_scale) / 2.0;
+                let candidate_w =
+                    ((orig_w as f64 * candidate_scale).round() as u32).clamp(1, orig_w);
+                let candidate_h =
+                    ((orig_h as f64 * candidate_scale).round() as u32).clamp(1, orig_h);
+                if (candidate_w, candidate_h) == under_dimensions {
+                    break;
                }
-            };

-            if should_update {
-                best_under = Some((result, new_w, new_h, result_size));
+                let candidate = image.resize_exact(
+                    candidate_w,
+                    candidate_h,
+                    image::imageops::FilterType::Lanczos3,
+                );
+                let candidate_result = encode_target_quality_with_image(
+                    &candidate,
+                    min_q,
+                    max_q,
+                    target_size,
+                    &mut encode_fn,
+                )?;
+                if candidate_result.len() as u64 <= target_size {
+                    best_under = candidate_result;
+                    under_scale = candidate_scale;
+                    under_dimensions = (candidate_w, candidate_h);
+                } else {
+                    over_scale = candidate_scale;
+                }
            }

-            if new_w == orig_w && new_h == orig_h && target_size.saturating_sub(result_size) <= 1024
-            {
-                break;
-            }
+            return Ok(best_under);
        } else {
            let should_update = match &best_over {
                None => true,
-                Some((_bytes, best_w, best_h, best_size)) => {
+                Some((_bytes, best_size, best_pixels)) => {
                    let over = result_size.saturating_sub(target_size);
                    let best_over_by = best_size.saturating_sub(target_size);
-                    if over < best_over_by {
-                        true
-                    } else if over == best_over_by {
-                        let new_pixels = (new_w as u64).saturating_mul(new_h as u64);
-                        let best_pixels = (*best_w as u64).saturating_mul(*best_h as u64);
-                        new_pixels > best_pixels
-                    } else {
-                        false
-                    }
+                    let new_pixels = (new_w as u64).saturating_mul(new_h as u64);
+                    over < best_over_by || (over == best_over_by && new_pixels > *best_pixels)
                }
            };

            if should_update {
-                best_over = Some((result, new_w, new_h, result_size));
+                let pixels = (new_w as u64).saturating_mul(new_h as u64);
+                best_over = Some((result, result_size, pixels));
            }
+            previous_over_scale = scale;
        }
    }

-    if let Some((bytes, _, _, _)) = best_under {
-        return Ok(bytes);
-    }
-    if let Some((bytes, _, _, _)) = best_over {
+    if let Some((bytes, _, _)) = best_over {
        return Ok(bytes);
    }

@@ -673,51 +693,34 @@ fn encode_target_quality_with_image<F>(
 where
    F: FnMut(&DynamicImage, u8) -> Result<Vec<u8>, AppError>,
 {
-    let mut best: Option<Vec<u8>> = None;
-    let mut best_diff = u64::MAX;
-    let mut best_is_under = false;
-
-    let mut consider = |bytes: Vec<u8>| {
-        let size = bytes.len() as u64;
-        let is_under = size <= target_size;
-        let diff = size.abs_diff(target_size);
-
-        let should_update = match (best_is_under, is_under) {
-            (false, true) => true,
-            (true, false) => false,
-            _ => diff < best_diff,
-        };
-
-        if should_update {
-            best_diff = diff;
-            best_is_under = is_under;
-            best = Some(bytes);
-        }
-    };
-
-    consider(encode_fn(image, min_q)?);
-    if min_q != max_q {
-        consider(encode_fn(image, max_q)?);
+    // Start with the highest quality. If it already fits, no lower-quality
+    // encodes can improve the result.
+    let max_quality = encode_fn(image, max_q)?;
+    if max_quality.len() as u64 <= target_size || min_q == max_q {
+        return Ok(max_quality);
    }

-    let mut low = min_q;
-    let mut high = max_q;
-    for _ in 0..12 {
-        if low > high {
-            break;
-        }
+    let min_quality = encode_fn(image, min_q)?;
+    if min_quality.len() as u64 > target_size {
+        return Ok(min_quality);
+    }
+
+    let mut best_under = min_quality;
+    let mut low = min_q.saturating_add(1);
+    let mut high = max_q.saturating_sub(1);
+    while low <= high {
        let mid = (low + high) / 2;
        let bytes = encode_fn(image, mid)?;
        let size = bytes.len() as u64;
-        consider(bytes);
        if size > target_size {
            high = mid.saturating_sub(1);
        } else {
+            best_under = bytes;
            low = mid.saturating_add(1);
        }
    }

-    best.ok_or_else(|| AppError::new(ErrorCode::CompressionFailed, "压缩失败"))
+    Ok(best_under)
 }

 fn encode_gif(image: DynamicImage, rate: u8) -> Result<Vec<u8>, AppError> {
@@ -765,6 +768,8 @@ fn encode_tiff(image: DynamicImage) -> Result<Vec<u8>, AppError> {
 }

 fn encode_ico(image: DynamicImage) -> Result<Vec<u8>, AppError> {
+    // A single ICO directory entry can represent at most 256x256 pixels.
+    let (image, _) = resize_if_needed(image, Some(256), Some(256));
    let rgba = image.to_rgba8();
    let (w, h) = rgba.dimensions();
    let mut out = Vec::new();
@@ -941,4 +946,61 @@ mod tests {
        assert_eq!(target_size_from_rate(10_000, 55), 5_500);
        assert_eq!(target_size_from_rate(10_000, 100), 10_000);
    }
+
+    #[test]
+    fn target_encoder_stops_when_full_resolution_meets_target() {
+        use std::cell::Cell;
+
+        let calls = Cell::new(0);
+        let image = DynamicImage::new_rgb8(800, 600);
+        let result = encode_with_auto_resize(image, 100, 40, 95, |_image, quality| {
+            calls.set(calls.get() + 1);
+            Ok(vec![0; quality as usize])
+        })
+        .unwrap();
+
+        assert_eq!(result.len(), 95);
+        assert_eq!(calls.get(), 1);
+    }
+
+    #[test]
+    fn target_encoder_can_reduce_a_landscape_at_the_long_edge_floor() {
+        let image = DynamicImage::new_rgb8(960, 640);
+        let result = encode_with_auto_resize(image, 40_000, 40, 40, |image, _quality| {
+            let (width, height) = image.dimensions();
+            Ok(vec![0; (width as usize * height as usize) / 10])
+        })
+        .unwrap();
+
+        assert!(result.len() <= 40_000);
+    }
+
+    #[test]
+    fn format_conversion_never_returns_the_original_encoding() {
+        let input = encode_png(DynamicImage::new_rgba8(10, 10), 100, false).unwrap();
+        let output = compress_image_bytes_sync(
+            input,
+            ImageFmt::Png,
+            ImageFmt::Bmp,
+            CompressionLevel::Medium,
+            None,
+            None,
+            None,
+            None,
+            false,
+            1_000_000,
+        )
+        .unwrap();
+
+        assert!(output.starts_with(b"BM"));
+    }
+
+    #[test]
+    fn ico_encoder_fits_large_images_within_the_format_limit() {
+        let output = encode_ico(DynamicImage::new_rgba8(960, 640)).unwrap();
+        let decoded = image::load_from_memory(&output).unwrap();
+
+        assert!(output.starts_with(b"\x00\x00\x01\x00"));
+        assert_eq!(decoded.dimensions(), (256, 171));
+    }
 }