diff --git a/apps/mobile/lib/l10n/app_en.arb b/apps/mobile/lib/l10n/app_en.arb
index 93c0ee5..f3e4425 100644
--- a/apps/mobile/lib/l10n/app_en.arb
+++ b/apps/mobile/lib/l10n/app_en.arb
@@ -429,5 +429,10 @@
   "posterSaveFailed": "Failed to save poster",
   "close": "Close",
   "albumUploadDisabled": "Upload is disabled for this album",
-  "networkOfflineBanner": "No network. Photos will upload automatically when reconnected."
+  "networkOfflineBanner": "No network. Photos will upload automatically when reconnected.",
+  "cropTitle": "Crop image",
+  "cropConfirm": "Done",
+  "cropCancel": "Cancel",
+  "cropProcessing": "Processing…",
+  "cropUnsupportedFormat": "This image format isn't supported yet — please pick JPG/PNG"
 }
diff --git a/apps/mobile/lib/l10n/app_localizations.dart b/apps/mobile/lib/l10n/app_localizations.dart
index 39ce691..c13f689 100644
--- a/apps/mobile/lib/l10n/app_localizations.dart
+++ b/apps/mobile/lib/l10n/app_localizations.dart
@@ -2029,6 +2029,36 @@ abstract class AppLocalizations {
   /// In zh, this message translates to:
   /// **'当前无网络连接，照片将在恢复后自动上传'**
   String get networkOfflineBanner;
+
+  /// No description provided for @cropTitle.
+  ///
+  /// In zh, this message translates to:
+  /// **'裁剪图片'**
+  String get cropTitle;
+
+  /// No description provided for @cropConfirm.
+  ///
+  /// In zh, this message translates to:
+  /// **'完成'**
+  String get cropConfirm;
+
+  /// No description provided for @cropCancel.
+  ///
+  /// In zh, this message translates to:
+  /// **'取消'**
+  String get cropCancel;
+
+  /// No description provided for @cropProcessing.
+  ///
+  /// In zh, this message translates to:
+  /// **'处理中…'**
+  String get cropProcessing;
+
+  /// No description provided for @cropUnsupportedFormat.
+  ///
+  /// In zh, this message translates to:
+  /// **'暂不支持该图片格式，请选择 JPG/PNG'**
+  String get cropUnsupportedFormat;
 }
 
 class _AppLocalizationsDelegate
diff --git a/apps/mobile/lib/l10n/app_localizations_en.dart b/apps/mobile/lib/l10n/app_localizations_en.dart
index 04ca0c0..fba570f 100644
--- a/apps/mobile/lib/l10n/app_localizations_en.dart
+++ b/apps/mobile/lib/l10n/app_localizations_en.dart
@@ -1038,4 +1038,20 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get networkOfflineBanner =>
       'No network. Photos will upload automatically when reconnected.';
+
+  @override
+  String get cropTitle => 'Crop image';
+
+  @override
+  String get cropConfirm => 'Done';
+
+  @override
+  String get cropCancel => 'Cancel';
+
+  @override
+  String get cropProcessing => 'Processing…';
+
+  @override
+  String get cropUnsupportedFormat =>
+      'This image format isn\'t supported yet — please pick JPG/PNG';
 }
diff --git a/apps/mobile/lib/l10n/app_localizations_zh.dart b/apps/mobile/lib/l10n/app_localizations_zh.dart
index 7c954f8..e73ec4a 100644
--- a/apps/mobile/lib/l10n/app_localizations_zh.dart
+++ b/apps/mobile/lib/l10n/app_localizations_zh.dart
@@ -1004,4 +1004,19 @@ class AppLocalizationsZh extends AppLocalizations {
 
   @override
   String get networkOfflineBanner => '当前无网络连接，照片将在恢复后自动上传';
+
+  @override
+  String get cropTitle => '裁剪图片';
+
+  @override
+  String get cropConfirm => '完成';
+
+  @override
+  String get cropCancel => '取消';
+
+  @override
+  String get cropProcessing => '处理中…';
+
+  @override
+  String get cropUnsupportedFormat => '暂不支持该图片格式，请选择 JPG/PNG';
 }
diff --git a/apps/mobile/lib/l10n/app_zh.arb b/apps/mobile/lib/l10n/app_zh.arb
index 0975e64..7ebb132 100644
--- a/apps/mobile/lib/l10n/app_zh.arb
+++ b/apps/mobile/lib/l10n/app_zh.arb
@@ -429,5 +429,10 @@
   "posterSaveFailed": "海报保存失败",
   "close": "关闭",
   "albumUploadDisabled": "该相册已关闭上传，无法添加照片",
-  "networkOfflineBanner": "当前无网络连接，照片将在恢复后自动上传"
+  "networkOfflineBanner": "当前无网络连接，照片将在恢复后自动上传",
+  "cropTitle": "裁剪图片",
+  "cropConfirm": "完成",
+  "cropCancel": "取消",
+  "cropProcessing": "处理中…",
+  "cropUnsupportedFormat": "暂不支持该图片格式，请选择 JPG/PNG"
 }
diff --git a/apps/mobile/lib/pages/album_form_page.dart b/apps/mobile/lib/pages/album_form_page.dart
index 8d10bd7..a4abefd 100644
--- a/apps/mobile/lib/pages/album_form_page.dart
+++ b/apps/mobile/lib/pages/album_form_page.dart
@@ -31,6 +31,7 @@ import '../features/uploads/enqueue.dart';
 import '../l10n/app_localizations.dart';
 import '../ui/components/section_header.dart';
 import '../ui/tokens.dart';
+import 'image_crop_page.dart';
 
 /// 创建（[existing] 为 null）/ 编辑相册表单。
 class AlbumFormPage extends ConsumerStatefulWidget {
@@ -497,17 +498,43 @@ class _AlbumFormPageState extends ConsumerState<AlbumFormPage>
     ],
   );
 
+  /// 选图后必经裁剪：封面 16:9（表单预览区比例），输出宽 ≤1920。
   Future<void> _pickCoverImage() async {
     final path = await ref.read(singleImagePickerProvider)();
-    if (path != null) {
-      setState(() => _coverFilePath = path);
+    if (path == null || !mounted) {
+      return;
+    }
+    final cropped = await Navigator.of(context).push<String>(
+      MaterialPageRoute(
+        builder: (_) => ImageCropPage(
+          sourcePath: path,
+          aspectRatio: 16 / 9,
+          maxOutputWidth: 1920,
+        ),
+      ),
+    );
+    if (cropped != null && mounted) {
+      setState(() => _coverFilePath = cropped);
     }
   }
 
+  /// 选图后必经裁剪：宣传图 3:1（观众页横幅），输出宽 ≤2400。
   Future<void> _pickBannerImage() async {
     final path = await ref.read(singleImagePickerProvider)();
-    if (path != null) {
-      setState(() => _bannerFilePath = path);
+    if (path == null || !mounted) {
+      return;
+    }
+    final cropped = await Navigator.of(context).push<String>(
+      MaterialPageRoute(
+        builder: (_) => ImageCropPage(
+          sourcePath: path,
+          aspectRatio: 3 / 1,
+          maxOutputWidth: 2400,
+        ),
+      ),
+    );
+    if (cropped != null && mounted) {
+      setState(() => _bannerFilePath = cropped);
     }
   }
 
diff --git a/apps/mobile/lib/pages/image_crop_page.dart b/apps/mobile/lib/pages/image_crop_page.dart
new file mode 100644
index 0000000..f868572
--- /dev/null
+++ b/apps/mobile/lib/pages/image_crop_page.dart
@@ -0,0 +1,307 @@
+/// 封面/宣传图裁剪页：固定纵横比交互裁剪 → 等比缩放上限 → JPEG 落盘。
+///
+/// 输入 image_picker 选中的本机路径；输出裁剪后的临时文件路径
+/// （`{tmp}/album_assets/crop_{ms}.jpg`）；取消/失败返回 null。
+/// 封面 16:9（输出宽 ≤1920）、宣传图 3:1（输出宽 ≤2400）由调用方给定。
+///
+/// crop_your_image 2.0.0 为回调式 API：`CropController.crop()` 是 void，
+/// 裁剪结果经 `onCropped` 回调（`CropSuccess.croppedImage` /
+/// `CropFailure.cause`）。像素级 decode/缩放/编码统一放
+/// `Isolate.run`，避免大图卡死主 isolate。
+library;
+
+import 'dart:io';
+import 'dart:isolate';
+import 'dart:typed_data';
+
+import 'package:crop_your_image/crop_your_image.dart';
+import 'package:flutter/material.dart';
+import 'package:image/image.dart' as img;
+
+import '../l10n/app_localizations.dart';
+import '../ui/tokens.dart';
+
+/// 裁剪页输出目录（应用临时目录下的 album_assets；测试直接可用真实 FS）。
+Directory _cropOutputDir() {
+  final dir = Directory(
+    '${Directory.systemTemp.path}${Platform.pathSeparator}album_assets',
+  );
+  dir.createSync(recursive: true);
+  return dir;
+}
+
+/// 裁剪字节 → 可解码格式预检（魔数嗅探；HEIC/GIF 等走不支持提示）。
+///
+/// 包内解析失败（`_parseImageWith` 的 compute 抛错）不会回调页面——
+/// 页面在交给 [Crop] 前先嗅探，拦下注定解析失败的源。
+/// GIF 明确不支持：包内 formatDetector 的兜底分支按 png 解码
+/// （`_ => ImageFormat.png`），decodePng(gif) 必然失败 → onStatusChanged
+/// 永不 ready → 页面挂死在加载态。
+bool _hasSupportedSignature(Uint8List bytes) {
+  if (bytes.length < 12) {
+    return false;
+  }
+  final jpeg = bytes[0] == 0xFF && bytes[1] == 0xD8 && bytes[2] == 0xFF;
+  final png =
+      bytes[0] == 0x89 &&
+      bytes[1] == 0x50 &&
+      bytes[2] == 0x4E &&
+      bytes[3] == 0x47;
+  final bmp = bytes[0] == 0x42 && bytes[1] == 0x4D;
+  final webp =
+      bytes[0] == 0x52 &&
+      bytes[1] == 0x49 &&
+      bytes[2] == 0x46 &&
+      bytes[3] == 0x46 &&
+      bytes[8] == 0x57 &&
+      bytes[9] == 0x45 &&
+      bytes[10] == 0x42 &&
+      bytes[11] == 0x50;
+  return jpeg || png || bmp || webp;
+}
+
+/// 裁剪输出编码 + 落盘（只在 isolate 内执行）。
+String _encodeCropToJpeg(Uint8List cropped, int? maxOutputWidth) {
+  final decoded = img.decodeImage(cropped);
+  if (decoded == null) {
+    throw img.ImageException('crop output is not decodable');
+  }
+  var output = decoded;
+  if (maxOutputWidth != null && decoded.width > maxOutputWidth) {
+    output = img.copyResize(decoded, width: maxOutputWidth);
+  }
+  final file = File(
+    '${_cropOutputDir().path}${Platform.pathSeparator}'
+    'crop_${DateTime.now().millisecondsSinceEpoch}.jpg',
+  );
+  file.writeAsBytesSync(img.encodeJpg(output, quality: 90));
+  return file.path;
+}
+
+/// 封面/宣传图裁剪页。
+class ImageCropPage extends StatefulWidget {
+  const ImageCropPage({
+    super.key,
+    required this.sourcePath,
+    required this.aspectRatio,
+    this.maxOutputWidth,
+  });
+
+  /// 源图本机路径（image_picker 单选返回）。
+  final String sourcePath;
+
+  /// 目标宽高比（宽/高）：封面 16/9、宣传图 3/1。
+  final double aspectRatio;
+
+  /// 输出宽度上限（等比缩放；null=保持裁剪原分辨率）。
+  final int? maxOutputWidth;
+
+  @override
+  State<ImageCropPage> createState() => _ImageCropPageState();
+}
+
+class _ImageCropPageState extends State<ImageCropPage> {
+  final CropController _controller = CropController();
+
+  late final Future<Uint8List> _sourceBytes;
+
+  /// 源读取完成且魔数预检通过（可裁剪）。
+  bool _ready = false;
+
+  /// 包内解析完成（CropStatus.ready；完成按钮需等解析完再开放）。
+  bool _cropReady = false;
+
+  /// 源读取失败或预检不通过（HEIC 等不支持的格式）。
+  bool _unsupported = false;
+
+  /// 编码落盘中（遮罩 + 防重复点击）。
+  bool _processing = false;
+
+  @override
+  void initState() {
+    super.initState();
+    _sourceBytes = File(widget.sourcePath).readAsBytes();
+    _sourceBytes
+        .then((bytes) {
+          if (!mounted) {
+            return;
+          }
+          setState(() {
+            _ready = _hasSupportedSignature(bytes);
+            _unsupported = !_ready;
+          });
+        })
+        .catchError((Object _) {
+          if (!mounted) {
+            return;
+          }
+          setState(() => _unsupported = true);
+        });
+  }
+
+  void _cancel() {
+    Navigator.of(context).pop(null);
+  }
+
+  void _confirm() {
+    if (_processing || !_ready || !_cropReady) {
+      return;
+    }
+    setState(() => _processing = true);
+    // crop() 为 void：结果经 onCropped 回调。
+    _controller.crop();
+  }
+
+  /// 包内状态回调：解析完成（ready）才允许确认，防 crop() 在解析前触发的断言。
+  void _onCropStatus(CropStatus status) {
+    final ready = status == CropStatus.ready;
+    if (ready == _cropReady) {
+      return;
+    }
+    setState(() => _cropReady = ready);
+  }
+
+  Future<void> _onCropped(CropResult result) async {
+    if (!mounted) {
+      return;
+    }
+    if (result is! CropSuccess) {
+      _fail();
+      return;
+    }
+    // 仅捕获可发送值（Uint8List/int），闭包跨 isolate 复制。
+    final cropped = result.croppedImage;
+    final maxWidth = widget.maxOutputWidth;
+    try {
+      final outputPath = await Isolate.run(
+        () => _encodeCropToJpeg(cropped, maxWidth),
+      );
+      if (!mounted) {
+        return;
+      }
+      Navigator.of(context).pop(outputPath);
+    } on Object {
+      if (!mounted) {
+        return;
+      }
+      _fail();
+    }
+  }
+
+  /// 裁剪/编码失败：解除遮罩 + 提示，不 pop。
+  void _fail() {
+    setState(() => _processing = false);
+    ScaffoldMessenger.of(context).showSnackBar(
+      SnackBar(
+        content: Text(AppLocalizations.of(context).cropUnsupportedFormat),
+      ),
+    );
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final l10n = AppLocalizations.of(context);
+    // 编码落盘中拦截系统返回/ AppBar 返回（与底部取消禁用一致）。
+    return PopScope(
+      canPop: !_processing,
+      child: Scaffold(
+        appBar: AppBar(title: Text(l10n.cropTitle)),
+        body: Stack(
+          children: [
+            Positioned.fill(child: _buildBody(l10n)),
+            if (_processing)
+              Positioned.fill(
+                child: AbsorbPointer(
+                  child: ColoredBox(
+                    color: Colors.black54,
+                    child: Center(
+                      child: Column(
+                        mainAxisSize: MainAxisSize.min,
+                        children: [
+                          const CircularProgressIndicator(),
+                          const SizedBox(height: kSpace12),
+                          Text(
+                            l10n.cropProcessing,
+                            style: TextStyle(
+                              color: Theme.of(context).colorScheme.onPrimary,
+                            ),
+                          ),
+                        ],
+                      ),
+                    ),
+                  ),
+                ),
+              ),
+          ],
+        ),
+        bottomNavigationBar: SafeArea(
+          child: Padding(
+            padding: const EdgeInsets.fromLTRB(
+              kSpace16,
+              kSpace8,
+              kSpace16,
+              kSpace12,
+            ),
+            child: Row(
+              children: [
+                Expanded(
+                  child: TextButton(
+                    onPressed: _processing ? null : _cancel,
+                    child: Text(l10n.cropCancel),
+                  ),
+                ),
+                const SizedBox(width: kSpace12),
+                Expanded(
+                  child: FilledButton(
+                    onPressed: (_ready && _cropReady && !_processing)
+                        ? _confirm
+                        : null,
+                    child: Text(l10n.cropConfirm),
+                  ),
+                ),
+              ],
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+
+  Widget _buildBody(AppLocalizations l10n) {
+    if (_unsupported) {
+      return Center(
+        child: Padding(
+          padding: const EdgeInsets.all(kSpace16),
+          child: Text(
+            l10n.cropUnsupportedFormat,
+            textAlign: TextAlign.center,
+            style: Theme.of(context).textTheme.bodyMedium?.copyWith(
+              color: Theme.of(context).colorScheme.onSurfaceVariant,
+            ),
+          ),
+        ),
+      );
+    }
+    return FutureBuilder<Uint8List>(
+      future: _sourceBytes,
+      builder: (context, snapshot) {
+        if (snapshot.connectionState != ConnectionState.done ||
+            !snapshot.hasData) {
+          return const Center(child: CircularProgressIndicator());
+        }
+        return Crop(
+          image: snapshot.data!,
+          controller: _controller,
+          onCropped: _onCropped,
+          onStatusChanged: _onCropStatus,
+          aspectRatio: widget.aspectRatio,
+          // 交互模式 + 锁定裁剪框：用户平移/缩放图片适配固定比例框。
+          interactive: true,
+          fixCropRect: true,
+          baseColor: Theme.of(context).colorScheme.surfaceContainerHighest,
+          progressIndicator: const CircularProgressIndicator(strokeWidth: 2),
+        );
+      },
+    );
+  }
+}
diff --git a/apps/mobile/pubspec.lock b/apps/mobile/pubspec.lock
index 00cf77f..4808615 100644
--- a/apps/mobile/pubspec.lock
+++ b/apps/mobile/pubspec.lock
@@ -217,6 +217,14 @@ packages:
       url: "https://pub.flutter-io.cn"
     source: hosted
     version: "3.1.2"
+  crop_your_image:
+    dependency: "direct main"
+    description:
+      name: crop_your_image
+      sha256: "14c8977b11a009dc5e73e0f6522970f93363e38183f1b2ffefe1676dc9c3f49d"
+      url: "https://pub.flutter-io.cn"
+    source: hosted
+    version: "2.0.0"
   cross_file:
     dependency: transitive
     description:
@@ -568,7 +576,7 @@ packages:
     source: hosted
     version: "4.1.2"
   image:
-    dependency: transitive
+    dependency: "direct main"
     description:
       name: image
       sha256: a1e7f4951e538a568e14b856702afc9ae1d2f4b202daced8d22c1b9cd211ce89
diff --git a/apps/mobile/pubspec.yaml b/apps/mobile/pubspec.yaml
index b5cf839..8b84d49 100644
--- a/apps/mobile/pubspec.yaml
+++ b/apps/mobile/pubspec.yaml
@@ -42,6 +42,10 @@ dependencies:
   gal: ^2.3.3
   fluwx: ^6.0.2
   connectivity_plus: ^7.3.1
+  # 封面/宣传图裁剪（纯 Flutter）
+  crop_your_image: ^2.0.0
+  # 像素编码输出（裁剪页直接 import）
+  image: ^4.3.0
 
 
 flutter_launcher_icons:
diff --git a/apps/mobile/test/pages/image_crop_page_test.dart b/apps/mobile/test/pages/image_crop_page_test.dart
new file mode 100644
index 0000000..889d9c3
--- /dev/null
+++ b/apps/mobile/test/pages/image_crop_page_test.dart
@@ -0,0 +1,208 @@
+/// 封面/宣传图裁剪页 widget 测试（crop_your_image 回调式 API）。
+///
+/// 真实异步边界（源文件读取 + 包内 parse/crop 的 compute + 编码落盘
+/// Isolate.run）在 testWidgets 的 FakeAsync 下不会自行推进——参照
+/// crop_your_image 自身测试的驱动方式：tap + 等待都包进 tester.runAsync，
+/// 用真实 Future.delayed 等 isolate 完成。
+library;
+
+import 'dart:io';
+
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:image/image.dart' as img;
+import 'package:photo_live/l10n/app_localizations.dart';
+import 'package:photo_live/pages/image_crop_page.dart';
+
+void main() {
+  late final Directory tmp;
+  late final String fixtureJpg;
+  late final String fixtureGif;
+
+  setUpAll(() {
+    tmp = Directory.systemTemp.createTempSync('image_crop_page_test');
+    // 320x240（4:3）JPG 夹具：运行时生成，避免仓库二进制资产。
+    final source = img.Image(width: 320, height: 240, numChannels: 3);
+    img.fill(source, color: img.ColorRgb8(80, 120, 200));
+    fixtureJpg = '${tmp.path}${Platform.pathSeparator}fixture.jpg';
+    File(fixtureJpg).writeAsBytesSync(img.encodeJpg(source, quality: 90));
+    // GIF 夹具：包内 formatDetector 兜底按 png 解码必然失败挂起，
+    // 页面预检须直接判不支持（防 never-ready）。
+    fixtureGif = '${tmp.path}${Platform.pathSeparator}fixture.gif';
+    File(fixtureGif).writeAsBytesSync(img.encodeGif(source));
+  });
+
+  tearDownAll(() {
+    tmp.deleteSync(recursive: true);
+  });
+
+  /// 打开裁剪页（zh 本地化）；onPopped 接住 pop 结果。
+  Future<void> openCropPage(
+    WidgetTester tester,
+    String sourcePath, {
+    required double aspectRatio,
+    int? maxOutputWidth,
+    void Function(String? value)? onPopped,
+  }) async {
+    await tester.pumpWidget(
+      MaterialApp(
+        locale: const Locale('zh'),
+        localizationsDelegates: AppLocalizations.localizationsDelegates,
+        supportedLocales: AppLocalizations.supportedLocales,
+        home: Scaffold(
+          body: Builder(
+            builder: (context) => Center(
+              child: FloatingActionButton(
+                onPressed: () async {
+                  final value = await Navigator.of(context).push<String>(
+                    MaterialPageRoute(
+                      builder: (_) => ImageCropPage(
+                        sourcePath: sourcePath,
+                        aspectRatio: aspectRatio,
+                        maxOutputWidth: maxOutputWidth,
+                      ),
+                    ),
+                  );
+                  onPopped?.call(value);
+                },
+              ),
+            ),
+          ),
+        ),
+      ),
+    );
+    await tester.runAsync(() async {
+      await tester.tap(find.byType(FloatingActionButton));
+      await tester.pump();
+      await tester.pump(const Duration(milliseconds: 500));
+      // 真实异步必须「等→pump→再等→再 pump」：读取完成后经 pump 才构建
+      // Crop（parse compute 此刻才启动），需再等真实时间让 isolate 回复落地。
+      await Future.delayed(const Duration(seconds: 2));
+      await tester.pump();
+      await Future.delayed(const Duration(seconds: 2));
+      await tester.pump();
+    });
+    await tester.pump();
+  }
+
+  testWidgets('取消 → pop(null)', (tester) async {
+    String? popped = 'sentinel';
+    await openCropPage(
+      tester,
+      fixtureJpg,
+      aspectRatio: 16 / 9,
+      onPopped: (value) => popped = value,
+    );
+
+    await tester.runAsync(() async {
+      await tester.tap(find.text('取消'));
+      await tester.pump();
+    });
+    await tester.pumpAndSettle();
+
+    expect(popped, isNull);
+  });
+
+  testWidgets('确认 → pop 出存在的 .jpg 路径', (tester) async {
+    String? popped;
+    await openCropPage(
+      tester,
+      fixtureJpg,
+      aspectRatio: 16 / 9,
+      maxOutputWidth: 1920,
+      onPopped: (value) => popped = value,
+    );
+
+    await tester.runAsync(() async {
+      await tester.tap(find.text('完成'));
+      await tester.pump();
+      // crop（compute）→ 编码落盘（Isolate.run）→ pop。
+      await Future.delayed(const Duration(seconds: 5));
+      await tester.pump();
+    });
+    await tester.pumpAndSettle();
+
+    expect(popped, isNotNull);
+    expect(popped!.endsWith('.jpg'), isTrue);
+    expect(File(popped!).existsSync(), isTrue);
+  });
+
+  testWidgets('确认 → 输出尊重 maxOutputWidth 且保持纵横比', (tester) async {
+    String? popped;
+    await openCropPage(
+      tester,
+      fixtureJpg,
+      aspectRatio: 16 / 9,
+      maxOutputWidth: 160,
+      onPopped: (value) => popped = value,
+    );
+
+    await tester.runAsync(() async {
+      await tester.tap(find.text('完成'));
+      await tester.pump();
+      await Future.delayed(const Duration(seconds: 5));
+      await tester.pump();
+    });
+    await tester.pumpAndSettle();
+
+    expect(popped, isNotNull);
+    final decoded = img.decodeImage(File(popped!).readAsBytesSync());
+    expect(decoded, isNotNull);
+    expect(decoded!.width, 160);
+    expect(decoded.height, 90);
+  });
+
+  testWidgets('非图片源 → 提示不支持且不 pop', (tester) async {
+    final bogus = File('${tmp.path}${Platform.pathSeparator}bogus.jpg');
+    bogus.writeAsStringSync('definitely not an image');
+
+    final popped = <String?>[];
+    await openCropPage(
+      tester,
+      bogus.path,
+      aspectRatio: 3 / 1,
+      onPopped: popped.add,
+    );
+
+    await tester.pump();
+    expect(find.text('暂不支持该图片格式，请选择 JPG/PNG'), findsOneWidget);
+    expect(popped, isEmpty);
+    // 完成不可用（无裁剪可做）。
+    final done = find.text('完成');
+    expect(
+      tester
+          .widget<FilledButton>(
+            find.ancestor(of: done, matching: find.byType(FilledButton)),
+          )
+          .enabled,
+      isFalse,
+    );
+
+    bogus.deleteSync();
+  });
+
+  testWidgets('GIF 源 → 预检判不支持（防包内 png 兜底解码挂起）且不 pop',
+      (tester) async {
+    final popped = <String?>[];
+    await openCropPage(
+      tester,
+      fixtureGif,
+      aspectRatio: 16 / 9,
+      onPopped: popped.add,
+    );
+
+    await tester.pump();
+    expect(find.text('暂不支持该图片格式，请选择 JPG/PNG'), findsOneWidget);
+    expect(popped, isEmpty);
+    // 完成不可用：包内若按 png 兜底解析 GIF，将永远到不了 ready。
+    final done = find.text('完成');
+    expect(
+      tester
+          .widget<FilledButton>(
+            find.ancestor(of: done, matching: find.byType(FilledButton)),
+          )
+          .enabled,
+      isFalse,
+    );
+  });
+}