diff --git a/README.md b/README.md
index e69de29..4f69e67 100644
--- a/README.md
+++ b/README.md
@@ -0,0 +1,86 @@
+# pptopic
+
+将 PowerPoint 演示文稿导出为长图的工具。
+
+## 功能
+
+- 将 PPTX 文件的所有幻灯片垂直拼接为一张长图
+- 支持 JPG 和 PNG 格式输出
+- 支持自定义输出宽度和目录
+- 内置图片优化功能，使用图片优化引擎进行无损压缩
+
+## 安装
+
+### 安装 uv
+
+```bash
+# 使用 scoop
+scoop install uv
+```
+
+### 安装 pptopic
+
+```bash
+uv pip install -e .
+```
+
+## 使用
+
+### 导出 PPTX 为长图
+
+```bash
+# 基本用法
+pptopic export presentation.pptx
+
+# 指定输出文件名
+pptopic export presentation.pptx --output result.png
+
+# 优化导出的图片
+pptopic export presentation.pptx --optimize
+
+# 自定义宽度和最大高度
+pptopic export presentation.pptx --width 1080 --optimize --max-height 20000
+```
+
+### 单独优化图片
+
+```bash
+# 优化图片
+pptopic optimize image.png
+
+# 指定输出文件
+pptopic optimize image.png --output optimized.png
+
+# 自定义优化参数
+pptopic optimize image.png --max-height 20000 --engine pngquant
+```
+
+## 系统要求
+
+- Windows 系统（使用 win32com 调用 PowerPoint）
+- Python >= 3.13
+- Microsoft PowerPoint
+
+## 图片优化
+
+推荐使用 [pngquant](https://pngquant.org/) 进行图片压缩。
+
+### 自动安装脚本
+
+使用提供的 PowerShell 脚本自动安装 pngquant：
+
+```powershell
+.\install-pngquant.ps1
+```
+
+该脚本会自动：
+1. 检查 pngquant 是否已安装
+2. 如果未安装，检查 scoop 是否已安装
+3. 如果 scoop 未安装，自动安装 scoop
+4. 使用 scoop 安装 pngquant
+
+### 手动安装
+
+```bash
+scoop install pngquant
+```
diff --git a/install-pngquant.ps1 b/install-pngquant.ps1
new file mode 100644
index 0000000..d77012c
--- /dev/null
+++ b/install-pngquant.ps1
@@ -0,0 +1,114 @@
+param(
+    [switch]$Force
+)
+
+$ErrorActionPreference = "Stop"
+
+function Test-PngquantInstalled {
+    try {
+        $result = Get-Command pngquant -ErrorAction Stop
+        Write-Host "pngquant 已安装: $($result.Source)" -ForegroundColor Green
+        return $true
+    } catch {
+        Write-Host "pngquant 未安装" -ForegroundColor Yellow
+        return $false
+    }
+}
+
+function Test-ScoopInstalled {
+    try {
+        $result = Get-Command scoop -ErrorAction Stop
+        Write-Host "scoop 已安装: $($result.Source)" -ForegroundColor Green
+        return $true
+    } catch {
+        Write-Host "scoop 未安装" -ForegroundColor Yellow
+        return $false
+    }
+}
+
+function Install-Scoop {
+    Write-Host "正在安装 scoop..." -ForegroundColor Cyan
+    
+    $scoopInstallScript = "irm get.scoop.sh | iex"
+    
+    try {
+        Invoke-Expression $scoopInstallScript
+        Write-Host "scoop 安装成功" -ForegroundColor Green
+        
+        $env:Path = [System.Environment]::GetEnvironmentVariable("Path","User") + ";" + [System.Environment]::GetEnvironmentVariable("Path","Machine")
+        
+        return $true
+    } catch {
+        Write-Host "scoop 安装失败: $_" -ForegroundColor Red
+        return $false
+    }
+}
+
+function Install-Pngquant {
+    Write-Host "正在使用 scoop 安装 pngquant..." -ForegroundColor Cyan
+    
+    try {
+        scoop install pngquant
+        Write-Host "pngquant 安装成功" -ForegroundColor Green
+        return $true
+    } catch {
+        Write-Host "pngquant 安装失败: $_" -ForegroundColor Red
+        return $false
+    }
+}
+
+Write-Host "========================================" -ForegroundColor Cyan
+Write-Host "  pngquant 安装脚本" -ForegroundColor Cyan
+Write-Host "========================================" -ForegroundColor Cyan
+Write-Host ""
+
+if (Test-PngquantInstalled) {
+    Write-Host ""
+    Write-Host "pngquant 已经安装，无需重复安装。" -ForegroundColor Green
+    if (-not $Force) {
+        exit 0
+    }
+    Write-Host "使用 -Force 参数强制重新安装..." -ForegroundColor Yellow
+}
+
+Write-Host ""
+
+if (-not (Test-ScoopInstalled)) {
+    Write-Host ""
+    Write-Host "scoop 未安装，正在安装 scoop..." -ForegroundColor Yellow
+    
+    if (-not (Install-Scoop)) {
+        Write-Host ""
+        Write-Host "scoop 安装失败，请手动安装后重试。" -ForegroundColor Red
+        Write-Host "手动安装命令: irm get.scoop.sh | iex" -ForegroundColor Yellow
+        exit 1
+    }
+    
+    Write-Host ""
+    Write-Host "请重新运行此脚本以继续安装 pngquant。" -ForegroundColor Yellow
+    Write-Host "或者手动运行: scoop install pngquant" -ForegroundColor Yellow
+    exit 0
+}
+
+Write-Host ""
+
+if (Install-Pngquant) {
+    Write-Host ""
+    Write-Host "========================================" -ForegroundColor Green
+    Write-Host "  pngquant 安装完成！" -ForegroundColor Green
+    Write-Host "========================================" -ForegroundColor Green
+    
+    $pngquantPath = Get-Command pngquant -ErrorAction SilentlyContinue
+    if ($pngquantPath) {
+        Write-Host "安装路径: $($pngquantPath.Source)" -ForegroundColor Cyan
+    }
+    
+    Write-Host ""
+    Write-Host "验证安装:" -ForegroundColor Cyan
+    pngquant --version
+} else {
+    Write-Host ""
+    Write-Host "pngquant 安装失败。" -ForegroundColor Red
+    Write-Host "请尝试手动安装: scoop install pngquant" -ForegroundColor Yellow
+    exit 1
+}
diff --git a/pyproject.toml b/pyproject.toml
index f49979d..f4ded6b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,3 +1,7 @@
+[build-system]
+requires = ["hatchling"]
+build-backend = "hatchling.build"
+
 [project]
 name = "pptopic"
 version = "0.1.0"
@@ -16,9 +20,47 @@ dependencies = [
     "typer>=0.21.2",
 ]
 
+[project.optional-dependencies]
+dev = [
+    "pytest>=8.0.0",
+    "pytest-cov>=4.0.0",
+    "pytest-mock>=3.10.0",
+]
+
 [project.scripts]
 pptopic = "pptopic:main"
 
-[build-system]
-requires = ["uv_build>=0.9.18,<0.10.0"]
-build-backend = "uv_build"
+[tool.pytest.ini_options]
+testpaths = ["tests"]
+python_files = ["test_*.py"]
+python_classes = ["Test*"]
+python_functions = ["test_*"]
+addopts = [
+    "-ra",
+    "-q",
+    "--strict-markers",
+    "--strict-config",
+]
+markers = [
+    "slow: marks tests as slow (deselect with '-m \"not slow\"')",
+    "integration: marks tests as integration tests",
+    "unit: marks tests as unit tests",
+]
+
+[tool.coverage.run]
+source = ["src/pptopic"]
+omit = [
+    "*/tests/*",
+    "*/test_*.py",
+]
+
+[tool.coverage.report]
+exclude_lines = [
+    "pragma: no cover",
+    "def __repr__",
+    "raise AssertionError",
+    "raise NotImplementedError",
+    "if __name__ == .__main__.:",
+    "if TYPE_CHECKING:",
+    "@abstractmethod",
+]
diff --git a/pytest.ini b/pytest.ini
new file mode 100644
index 0000000..71fa3f5
--- /dev/null
+++ b/pytest.ini
@@ -0,0 +1,16 @@
+[tool.pytest.ini_options]
+testpaths = ["tests"]
+python_files = ["test_*.py"]
+python_classes = ["Test*"]
+python_functions = ["test_*"]
+addopts = [
+    "-ra",
+    "-q",
+    "--strict-markers",
+    "--strict-config",
+]
+markers = [
+    "slow: marks tests as slow (deselect with '-m \"not slow\"')",
+    "integration: marks tests as integration tests",
+    "unit: marks tests as unit tests",
+]
diff --git a/src/pptopic/lib.py b/src/pptopic/lib.py
index f290c04..b7438d0 100644
--- a/src/pptopic/lib.py
+++ b/src/pptopic/lib.py
@@ -24,101 +24,109 @@ class convertPPT(object):
         "PDF" : 32,
         "XPS" : 33
     }
-    __all__ = ["savetype", "trans", "close", "open"]
 
-    def __init__(self, file:str|Path, trans:str = "JPG") -> None:
+    def __init__(self, file: str | Path, trans: str = "JPG") -> None:
         if sys.platform != "win32":
             raise SystemError("Only support Windows system.")
-        if not Path(file).exists():
-            raise FileNotFoundError("File not found! Please check the file path.")
-        if trans.upper() not in convertPPT.TTYPES.keys():
-            raise ValueError("Save type is not supported.")
         self.__file = Path(file)
-        self.__saveType = (convertPPT.TTYPES[trans.upper()], trans.upper())
+        if not self.__file.exists():
+            raise FileNotFoundError("File not found! Please check the file path.")
+        trans_upper = trans.upper()
+        if trans_upper not in convertPPT.TTYPES:
+            raise ValueError("Save type is not supported.")
+        self.__saveType = (convertPPT.TTYPES[trans_upper], trans_upper)
         self.__inUsing = wcc.Dispatch('PowerPoint.Application')
+
     def __enter__(self) -> Self:
         return self
+
     def __exit__(self, exc_type, exc_value, traceback) -> None:
         self.close()
+
     @property
-    def savetype(self) -> str :
+    def savetype(self) -> str:
         return self.__saveType[1]
+
     @classmethod
-    def open(cls, file:str|Path, trans:str = "JPG") -> Self :
-        return cls(file, trans = trans.upper())
-    def saveAs(self, saveType:str|None = None) -> None :
-        if saveType not in convertPPT.TTYPES.keys():
-            raise ValueError("Save type is not supported.")
-        if saveType is not None:
-            self.__saveType = (convertPPT.TTYPES[saveType.upper()], saveType.upper())
-        else:
+    def open(cls, file: str | Path, trans: str = "JPG") -> Self:
+        return cls(file, trans=trans.upper())
+
+    def saveAs(self, saveType: str | None = None) -> None:
+        if saveType is None:
             self.__saveType = (convertPPT.TTYPES["JPG"], "JPG")
-    def trans(self, saveto:str|Path = ".", 
-              width:int|None = None) -> None :
+        else:
+            saveType_upper = saveType.upper()
+            if saveType_upper not in convertPPT.TTYPES:
+                raise ValueError("Save type is not supported.")
+            self.__saveType = (convertPPT.TTYPES[saveType_upper], saveType_upper)
+
+    def trans(self, saveto: str | Path = ".", width: int | None = None) -> None:
         """
         saveto : 保存路径，默认为当前路径。
         """
         ppt = self.__inUsing.Presentations.Open(self.__file.absolute())
-        if Path(saveto) == Path('.') :
-            output = self.__file.absolute()
-        else :
-            output = Path(saveto).absolute()
-        if width is not None :
+        output = Path(saveto).absolute()
+        if width is not None:
             ppt.Export(output, self.__saveType[1], width)
         else:
             ppt.SaveAs(output, self.__saveType[0])
-    def close(self, to_console:bool = False) -> None :
+
+    def close(self, to_console: bool = False) -> None:
         self.__inUsing.Quit()
-        if to_console :
+        if to_console:
             print("File converted successfully.")
 
 
-def PPT_longPic(pptFile:str|Path, saveName:str|None = None, width:int|str|None = None, 
-                saveto:str|Path = ".") -> None :
+def PPT_longPic(pptFile: str | Path, saveName: str | None = None, width: int | str | None = None,
+                saveto: str | Path = ".") -> None:
     """
     width : 画幅宽度，可以直接指定宽度像素，也可以使用字符串数据输入百分比。
             （700； "22.1%"）
                 指定为None的时候，不进行图像缩放。
     """
-    if saveName :
-        sType = saveName.split(".")[-1] if "." in saveName else "JPG"
-        if sType.upper() not in ["JPG", "PNG"] :
+    pptFile = Path(pptFile)
+    if saveName:
+        sType = Path(saveName).suffix[1:].upper() if Path(saveName).suffix else "JPG"
+        if sType not in ["JPG", "PNG"]:
             raise ValueError("Unable to save this type `{}` of image.".format(sType))
     else:
         sType = "JPG"
+
     with TemporaryDirectory() as tmpdirname:
         with convertPPT(pptFile, trans=sType) as ppt:
             ppt.trans(saveto=tmpdirname)
-        picList = list(Path(tmpdirname).glob("*.{}".format(sType)))
-        with Image.open(picList[0]) as img :
+        picList = sorted(Path(tmpdirname).glob("*.{}".format(sType)))
+        if not picList:
+            raise ValueError("No images generated from PPT conversion.")
+        
+        with Image.open(picList[0]) as img:
             if isinstance(width, str):
-                qw = float(width[:-1])/100.0
-                nwidth, nheight = (int(img.width*qw), int(img.height*qw))
+                qw = float(width.rstrip('%')) / 100.0
+                nwidth, nheight = (int(img.width * qw), int(img.height * qw))
             elif width is None:
                 nwidth, nheight = img.size
             else:
-                nwidth, nheight = (width, int(img.height*width/img.width))
+                nwidth, nheight = (width, int(img.height * width / img.width))
             canvas = Image.new(img.mode, (nwidth, nheight * len(picList)))
-        for i in range(1,len(picList)+1) :
-            with Image.open(Path(tmpdirname).joinpath("幻灯片{}.{}".format(i,sType))) as img :
-                new_img = img.resize((nwidth,nheight), resample=Image.Resampling.LANCZOS)
-                canvas.paste(new_img, box=(0, (i-1) * nheight))
-        if Path(saveto) == Path('.') :
-            filepath = Path(pptFile).parent
-        else :
-            filepath = Path(saveto)
-        if saveName :
-            if '.' in saveName :
-                canvas.save(filepath.joinpath(saveName))
-            else:
-                canvas.save(filepath.joinpath(saveName), format=sType)
-        else:
-            canvas.save(filepath.joinpath(Path(pptFile).stem), format=sType)
 
-def imageOptimization(imageFile:str|Path|Image.Image, saveFile:str|Path|None = None, 
-             max_width:int = None, max_height:int = None, 
-             engine:str|None = "pngquant",
-             engine_conf:str|None = None) -> Image.Image|None :
+        for i, picPath in enumerate(picList, 1):
+            with Image.open(picPath) as img:
+                new_img = img.resize((nwidth, nheight), resample=Image.Resampling.LANCZOS)
+                canvas.paste(new_img, box=(0, (i - 1) * nheight))
+
+        filepath = pptFile.parent if Path(saveto) == Path('.') else Path(saveto)
+        if saveName:
+            if Path(saveName).suffix:
+                canvas.save(filepath / saveName)
+            else:
+                canvas.save(filepath / saveName, format=sType)
+        else:
+            canvas.save(filepath / pptFile.name, format=sType)
+
+def imageOptimization(imageFile: str | Path | Image.Image, saveFile: str | Path | None = None,
+             max_width: int = None, max_height: int = None,
+             engine: str | None = "pngquant",
+             engine_conf: str | None = None) -> Image.Image | None:
     """图片优化、无损压缩
     默认建议使用pngquant进行无损压缩，也可以设置为其他图片无损压缩引擎，
     不需要针对性压缩，可设定engine为None。
@@ -126,42 +134,50 @@ def imageOptimization(imageFile:str|Path|Image.Image, saveFile:str|Path|None = N
     if isinstance(imageFile, (str, Path)):
         imageFile = Image.open(imageFile)
     img = cv2.cvtColor(np.array(imageFile), cv2.COLOR_RGB2BGR)
-    if max_width or max_height :
+    
+    if max_width or max_height:
         height, width, _ = img.shape
-        oShape = (width, height)
-        if max_width :
-            if width > max_width :
-                height = int(height * max_width / width)
-                width = max_width
-            if max_width < 1 :
-                width = int(width * max_width)
-                height = int(height * max_width)
-        if max_height :
-            if height > max_height :
-                width = int(width * max_height / height)
-                height = max_height
-            if max_height < 1 :
-                if width < oShape[0] :
-                    if height / oShape[1] > max_height :
-                        height = int(oShape[1] * max_height)
-                        width = int(oShape[0] * max_height)
+        new_width, new_height = width, height
+        
+        if max_width:
+            if max_width < 1:
+                new_width = int(width * max_width)
+                new_height = int(height * max_width)
+            elif width > max_width:
+                new_width = max_width
+                new_height = int(height * max_width / width)
+        
+        if max_height:
+            if max_height < 1:
+                if new_width < width:
+                    if new_height / height > max_height:
+                        new_height = int(height * max_height)
+                        new_width = int(width * max_height)
                 else:
-                    height = int(height * max_height)
-                    width = int(width * max_height)
-        img = cv2.resize(img, (width, height))
+                    new_height = int(new_height * max_height)
+                    new_width = int(new_width * max_height)
+            elif new_height > max_height:
+                new_width = int(new_width * max_height / new_height)
+                new_height = max_height
+        
+        img = cv2.resize(img, (new_width, new_height))
+    
     res = Image.fromarray(cv2.cvtColor(img, cv2.COLOR_BGR2RGB))
-    with TemporaryDirectory(prefix="pytoolsz") as tmpFolder :
-        res.save(Path(tmpFolder)/"tmp.png", compress_level=2, quality=100)
-        if engine :
+    with TemporaryDirectory(prefix="pytoolsz") as tmpFolder:
+        tmpPath = Path(tmpFolder) / "tmp.png"
+        res.save(tmpPath, compress_level=2, quality=100)
+        
+        if engine:
             try:
-                subprocess.run([engine, engine_conf, Path(tmpFolder)/"tmp.png"], shell=True, check=True)
+                subprocess.run([engine, engine_conf, tmpPath], shell=True, check=True)
             except Exception as e:
                 print("未安装pngquant，不能进行图片优化压缩。\n可使用`scoop install pngquant`进行安装。")
                 raise e
         else:
-            res.save(Path(tmpFolder)/"tmp.png", compress_level=7, quality=95)
-        if saveFile is None :
+            res.save(tmpPath, compress_level=7, quality=95)
+        
+        if saveFile is None:
             res = Image.open(lastFile(Path(tmpFolder), "*.*"))
             return res
-        else :
+        else:
             shutil.copyfile(lastFile(Path(tmpFolder), "*.*"), saveFile)
\ No newline at end of file
diff --git a/tests/README.md b/tests/README.md
new file mode 100644
index 0000000..403d5dc
--- /dev/null
+++ b/tests/README.md
@@ -0,0 +1,49 @@
+# 测试
+
+此目录包含 pptopic 库的测试文件。
+
+## 运行测试
+
+运行所有测试：
+
+```bash
+pytest
+```
+
+运行测试并生成覆盖率报告：
+
+```bash
+pytest --cov=pptopic --cov-report=html
+```
+
+运行特定测试文件：
+
+```bash
+pytest tests/test_convert.py
+```
+
+运行特定测试类：
+
+```bash
+pytest tests/test_convert.py::TestConvertPPTClass
+```
+
+运行特定测试函数：
+
+```bash
+pytest tests/test_convert.py::TestConvertPPTClass::test_init_with_valid_file
+```
+
+## 测试结构
+
+- `test_convert.py` - `convertPPT` 类的测试
+- `test_longpic.py` - `PPT_longPic` 函数的测试
+- `test_optimization.py` - `imageOptimization` 函数的测试
+
+## 测试标记
+
+测试可以使用以下标记：
+
+- `slow` - 慢速测试（可以使用 `-m "not slow"` 跳过）
+- `integration` - 集成测试
+- `unit` - 单元测试
diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 0000000..eecac51
--- /dev/null
+++ b/tests/__init__.py
@@ -0,0 +1,3 @@
+"""Test suite for pptopic library."""
+
+__version__ = "0.1.0"
diff --git a/tests/test_convert.py b/tests/test_convert.py
new file mode 100644
index 0000000..92882d8
--- /dev/null
+++ b/tests/test_convert.py
@@ -0,0 +1,150 @@
+"""Tests for convertPPT class."""
+
+import pytest
+from pathlib import Path
+from unittest.mock import Mock, MagicMock, patch
+from pptopic.lib import convertPPT
+
+
+class TestConvertPPTClass:
+    """Test convertPPT class initialization and properties."""
+
+    def test_ttypes_mapping(self):
+        """Test that TTYPES mapping is correct."""
+        assert convertPPT.TTYPES["JPG"] == 17
+        assert convertPPT.TTYPES["PNG"] == 18
+        assert convertPPT.TTYPES["PDF"] == 32
+        assert convertPPT.TTYPES["XPS"] == 33
+
+    @patch('pptopic.lib.sys.platform', 'win32')
+    def test_init_with_valid_file(self, tmp_path):
+        """Test initialization with a valid file path."""
+        test_file = tmp_path / "test.pptx"
+        test_file.touch()
+        
+        with patch('pptopic.lib.wcc.Dispatch') as mock_dispatch:
+            mock_app = MagicMock()
+            mock_dispatch.return_value = mock_app
+            
+            ppt = convertPPT(test_file, trans="JPG")
+            assert ppt.savetype == "JPG"
+            mock_dispatch.assert_called_once_with('PowerPoint.Application')
+
+    @patch('pptopic.lib.sys.platform', 'win32')
+    def test_init_with_path_object(self, tmp_path):
+        """Test initialization with Path object."""
+        test_file = tmp_path / "test.pptx"
+        test_file.touch()
+        
+        with patch('pptopic.lib.wcc.Dispatch'):
+            ppt = convertPPT(Path(test_file), trans="PNG")
+            assert ppt.savetype == "PNG"
+
+    @patch('pptopic.lib.sys.platform', 'win32')
+    def test_init_with_nonexistent_file(self):
+        """Test initialization with nonexistent file raises FileNotFoundError."""
+        with pytest.raises(FileNotFoundError, match="File not found"):
+            convertPPT("nonexistent.pptx")
+
+    @patch('pptopic.lib.sys.platform', 'win32')
+    def test_init_with_invalid_trans_type(self, tmp_path):
+        """Test initialization with invalid save type raises ValueError."""
+        test_file = tmp_path / "test.pptx"
+        test_file.touch()
+        
+        with pytest.raises(ValueError, match="Save type is not supported"):
+            convertPPT(test_file, trans="BMP")
+
+    @patch('pptopic.lib.sys.platform', 'win32')
+    def test_init_with_case_insensitive_trans(self, tmp_path):
+        """Test that trans parameter is case insensitive."""
+        test_file = tmp_path / "test.pptx"
+        test_file.touch()
+        
+        with patch('pptopic.lib.wcc.Dispatch'):
+            ppt = convertPPT(test_file, trans="jpg")
+            assert ppt.savetype == "JPG"
+            
+            ppt = convertPPT(test_file, trans="Pdf")
+            assert ppt.savetype == "PDF"
+
+
+class TestConvertPTTNonWindows:
+    """Test convertPPT behavior on non-Windows systems."""
+
+    @patch('pptopic.lib.sys.platform', 'linux')
+    def test_init_on_non_windows_raises_error(self):
+        """Test that initialization on non-Windows raises SystemError."""
+        with pytest.raises(SystemError, match="Only support Windows system"):
+            convertPPT("test.pptx")
+
+
+class TestConvertPPTContextManager:
+    """Test convertPPT as context manager."""
+
+    @patch('pptopic.lib.sys.platform', 'win32')
+    def test_context_manager_enter_exit(self, tmp_path):
+        """Test __enter__ and __exit__ methods."""
+        test_file = tmp_path / "test.pptx"
+        test_file.touch()
+        
+        with patch('pptopic.lib.wcc.Dispatch') as mock_dispatch:
+            mock_app = MagicMock()
+            mock_dispatch.return_value = mock_app
+            
+            with convertPPT(test_file) as ppt:
+                assert ppt.savetype == "JPG"
+            
+            mock_app.Quit.assert_called_once()
+
+
+class TestConvertPPTSaveAs:
+    """Test saveAs method."""
+
+    @patch('pptopic.lib.sys.platform', 'win32')
+    def test_saveas_default(self, tmp_path):
+        """Test saveAs with default parameter."""
+        test_file = tmp_path / "test.pptx"
+        test_file.touch()
+        
+        with patch('pptopic.lib.wcc.Dispatch'):
+            ppt = convertPPT(test_file, trans="PNG")
+            ppt.saveAs()
+            assert ppt.savetype == "JPG"
+
+    @patch('pptopic.lib.sys.platform', 'win32')
+    def test_saveas_with_valid_type(self, tmp_path):
+        """Test saveAs with valid save type."""
+        test_file = tmp_path / "test.pptx"
+        test_file.touch()
+        
+        with patch('pptopic.lib.wcc.Dispatch'):
+            ppt = convertPPT(test_file, trans="JPG")
+            ppt.saveAs("PDF")
+            assert ppt.savetype == "PDF"
+
+    @patch('pptopic.lib.sys.platform', 'win32')
+    def test_saveas_with_invalid_type(self, tmp_path):
+        """Test saveAs with invalid save type raises ValueError."""
+        test_file = tmp_path / "test.pptx"
+        test_file.touch()
+        
+        with patch('pptopic.lib.wcc.Dispatch'):
+            ppt = convertPPT(test_file, trans="JPG")
+            with pytest.raises(ValueError, match="Save type is not supported"):
+                ppt.saveAs("BMP")
+
+
+class TestConvertPTTOpenClassmethod:
+    """Test open class method."""
+
+    @patch('pptopic.lib.sys.platform', 'win32')
+    def test_open_classmethod(self, tmp_path):
+        """Test open class method creates instance."""
+        test_file = tmp_path / "test.pptx"
+        test_file.touch()
+        
+        with patch('pptopic.lib.wcc.Dispatch'):
+            ppt = convertPPT.open(test_file, trans="PNG")
+            assert ppt.savetype == "PNG"
+            assert isinstance(ppt, convertPPT)
diff --git a/tests/test_longpic.py b/tests/test_longpic.py
new file mode 100644
index 0000000..a6a3d76
--- /dev/null
+++ b/tests/test_longpic.py
@@ -0,0 +1,244 @@
+"""Tests for PPT_longPic function."""
+
+import pytest
+from pathlib import Path
+from unittest.mock import Mock, MagicMock, patch
+from PIL import Image
+from pptopic.lib import PPT_longPic
+
+
+class TestPPTLongPic:
+    """Test PPT_longPic function."""
+
+    @patch('pptopic.lib.convertPPT')
+    def test_ppt_longpic_with_save_name(self, mock_convert_ppt, tmp_path):
+        """Test PPT_longPic with saveName parameter."""
+        ppt_file = tmp_path / "test.pptx"
+        ppt_file.touch()
+        
+        mock_ppt = MagicMock()
+        mock_convert_ppt.return_value.__enter__.return_value = mock_ppt
+        
+        with patch('pptopic.lib.Path.glob') as mock_glob:
+            mock_img_path = MagicMock()
+            mock_img_path.suffix = '.jpg'
+            mock_glob.return_value = [mock_img_path]
+            
+            with patch('pptopic.lib.Image.open') as mock_open:
+                mock_img = MagicMock()
+                mock_img.mode = 'RGB'
+                mock_img.width = 100
+                mock_img.height = 100
+                mock_img.resize.return_value = mock_img
+                mock_open.return_value.__enter__.return_value = mock_img
+                
+                with patch('pptopic.lib.Image.new') as mock_new:
+                    mock_canvas = MagicMock()
+                    mock_new.return_value = mock_canvas
+                    
+                    PPT_longPic(ppt_file, saveName="output.jpg", saveto=tmp_path)
+                    
+                    mock_canvas.save.assert_called_once()
+
+    @patch('pptopic.lib.convertPPT')
+    def test_ppt_longpic_without_save_name(self, mock_convert_ppt, tmp_path):
+        """Test PPT_longPic without saveName uses default JPG."""
+        ppt_file = tmp_path / "test.pptx"
+        ppt_file.touch()
+        
+        mock_ppt = MagicMock()
+        mock_convert_ppt.return_value.__enter__.return_value = mock_ppt
+        
+        with patch('pptopic.lib.Path.glob') as mock_glob:
+            mock_img_path = MagicMock()
+            mock_img_path.suffix = '.jpg'
+            mock_glob.return_value = [mock_img_path]
+            
+            with patch('pptopic.lib.Image.open') as mock_open:
+                mock_img = MagicMock()
+                mock_img.mode = 'RGB'
+                mock_img.width = 100
+                mock_img.height = 100
+                mock_img.resize.return_value = mock_img
+                mock_open.return_value.__enter__.return_value = mock_img
+                
+                with patch('pptopic.lib.Image.new') as mock_new:
+                    mock_canvas = MagicMock()
+                    mock_new.return_value = mock_canvas
+                    
+                    PPT_longPic(ppt_file, saveto=tmp_path)
+                    
+                    mock_canvas.save.assert_called_once()
+
+    def test_ppt_longpic_invalid_image_type(self, tmp_path):
+        """Test PPT_longPic with invalid image type raises ValueError."""
+        ppt_file = tmp_path / "test.pptx"
+        ppt_file.touch()
+        
+        with pytest.raises(ValueError, match="Unable to save this type"):
+            PPT_longPic(ppt_file, saveName="output.bmp")
+
+    @patch('pptopic.lib.convertPPT')
+    def test_ppt_longpic_no_images_generated(self, mock_convert_ppt, tmp_path):
+        """Test PPT_longPic when no images are generated raises ValueError."""
+        ppt_file = tmp_path / "test.pptx"
+        ppt_file.touch()
+        
+        mock_ppt = MagicMock()
+        mock_convert_ppt.return_value.__enter__.return_value = mock_ppt
+        
+        with patch('pptopic.lib.Path.glob', return_value=[]):
+            with pytest.raises(ValueError, match="No images generated"):
+                PPT_longPic(ppt_file)
+
+    @patch('pptopic.lib.convertPPT')
+    def test_ppt_longpic_with_percentage_width(self, mock_convert_ppt, tmp_path):
+        """Test PPT_longPic with percentage width string."""
+        ppt_file = tmp_path / "test.pptx"
+        ppt_file.touch()
+        
+        mock_ppt = MagicMock()
+        mock_convert_ppt.return_value.__enter__.return_value = mock_ppt
+        
+        with patch('pptopic.lib.Path.glob') as mock_glob:
+            mock_img_path = MagicMock()
+            mock_img_path.suffix = '.jpg'
+            mock_glob.return_value = [mock_img_path]
+            
+            with patch('pptopic.lib.Image.open') as mock_open:
+                mock_img = MagicMock()
+                mock_img.mode = 'RGB'
+                mock_img.width = 100
+                mock_img.height = 100
+                mock_img.resize.return_value = mock_img
+                mock_open.return_value.__enter__.return_value = mock_img
+                
+                with patch('pptopic.lib.Image.new') as mock_new:
+                    mock_canvas = MagicMock()
+                    mock_new.return_value = mock_canvas
+                    
+                    PPT_longPic(ppt_file, width="50%", saveto=tmp_path)
+                    
+                    mock_new.assert_called_once()
+
+    @patch('pptopic.lib.convertPPT')
+    def test_ppt_longpic_with_pixel_width(self, mock_convert_ppt, tmp_path):
+        """Test PPT_longPic with pixel width."""
+        ppt_file = tmp_path / "test.pptx"
+        ppt_file.touch()
+        
+        mock_ppt = MagicMock()
+        mock_convert_ppt.return_value.__enter__.return_value = mock_ppt
+        
+        with patch('pptopic.lib.Path.glob') as mock_glob:
+            mock_img_path = MagicMock()
+            mock_img_path.suffix = '.jpg'
+            mock_glob.return_value = [mock_img_path]
+            
+            with patch('pptopic.lib.Image.open') as mock_open:
+                mock_img = MagicMock()
+                mock_img.mode = 'RGB'
+                mock_img.width = 100
+                mock_img.height = 100
+                mock_img.resize.return_value = mock_img
+                mock_open.return_value.__enter__.return_value = mock_img
+                
+                with patch('pptopic.lib.Image.new') as mock_new:
+                    mock_canvas = MagicMock()
+                    mock_new.return_value = mock_canvas
+                    
+                    PPT_longPic(ppt_file, width=50, saveto=tmp_path)
+                    
+                    mock_new.assert_called_once()
+
+    @patch('pptopic.lib.convertPPT')
+    def test_ppt_longpic_with_none_width(self, mock_convert_ppt, tmp_path):
+        """Test PPT_longPic with None width (no scaling)."""
+        ppt_file = tmp_path / "test.pptx"
+        ppt_file.touch()
+        
+        mock_ppt = MagicMock()
+        mock_convert_ppt.return_value.__enter__.return_value = mock_ppt
+        
+        with patch('pptopic.lib.Path.glob') as mock_glob:
+            mock_img_path = MagicMock()
+            mock_img_path.suffix = '.jpg'
+            mock_glob.return_value = [mock_img_path]
+            
+            with patch('pptopic.lib.Image.open') as mock_open:
+                mock_img = MagicMock()
+                mock_img.mode = 'RGB'
+                mock_img.width = 100
+                mock_img.height = 100
+                mock_img.resize.return_value = mock_img
+                mock_open.return_value.__enter__.return_value = mock_img
+                
+                with patch('pptopic.lib.Image.new') as mock_new:
+                    mock_canvas = MagicMock()
+                    mock_new.return_value = mock_canvas
+                    
+                    PPT_longPic(ppt_file, width=None, saveto=tmp_path)
+                    
+                    mock_new.assert_called_once()
+
+    @patch('pptopic.lib.convertPPT')
+    def test_ppt_longpic_save_to_current_dir(self, mock_convert_ppt, tmp_path):
+        """Test PPT_longPic saving to current directory."""
+        ppt_file = tmp_path / "test.pptx"
+        ppt_file.touch()
+        
+        mock_ppt = MagicMock()
+        mock_convert_ppt.return_value.__enter__.return_value = mock_ppt
+        
+        with patch('pptopic.lib.Path.glob') as mock_glob:
+            mock_img_path = MagicMock()
+            mock_img_path.suffix = '.jpg'
+            mock_glob.return_value = [mock_img_path]
+            
+            with patch('pptopic.lib.Image.open') as mock_open:
+                mock_img = MagicMock()
+                mock_img.mode = 'RGB'
+                mock_img.width = 100
+                mock_img.height = 100
+                mock_img.resize.return_value = mock_img
+                mock_open.return_value.__enter__.return_value = mock_img
+                
+                with patch('pptopic.lib.Image.new') as mock_new:
+                    mock_canvas = MagicMock()
+                    mock_new.return_value = mock_canvas
+                    
+                    PPT_longPic(ppt_file, saveto=".")
+                    
+                    mock_canvas.save.assert_called_once()
+
+    @patch('pptopic.lib.convertPPT')
+    def test_ppt_longpic_multiple_images(self, mock_convert_ppt, tmp_path):
+        """Test PPT_longPic with multiple images."""
+        ppt_file = tmp_path / "test.pptx"
+        ppt_file.touch()
+        
+        mock_ppt = MagicMock()
+        mock_convert_ppt.return_value.__enter__.return_value = mock_ppt
+        
+        with patch('pptopic.lib.Path.glob') as mock_glob:
+            mock_img_path1 = MagicMock()
+            mock_img_path1.suffix = '.jpg'
+            mock_img_path2 = MagicMock()
+            mock_img_path2.suffix = '.jpg'
+            mock_glob.return_value = [mock_img_path1, mock_img_path2]
+            
+            with patch('pptopic.lib.Image.open') as mock_open:
+                mock_img = MagicMock()
+                mock_img.mode = 'RGB'
+                mock_img.width = 100
+                mock_img.height = 100
+                mock_img.resize.return_value = mock_img
+                mock_open.return_value.__enter__.return_value = mock_img
+                
+                with patch('pptopic.lib.Image.new') as mock_new:
+                    mock_canvas = MagicMock()
+                    mock_new.return_value = mock_canvas
+                    
+                    PPT_longPic(ppt_file, saveto=tmp_path)
+                    
+                    mock_canvas.paste.assert_called()
diff --git a/tests/test_optimization.py b/tests/test_optimization.py
new file mode 100644
index 0000000..b62da5b
--- /dev/null
+++ b/tests/test_optimization.py
@@ -0,0 +1,227 @@
+"""Tests for imageOptimization function."""
+
+import pytest
+from pathlib import Path
+from unittest.mock import Mock, MagicMock, patch
+from PIL import Image
+import numpy as np
+from pptopic.lib import imageOptimization
+
+
+class TestImageOptimization:
+    """Test imageOptimization function."""
+
+    @patch('pptopic.lib.Image.open')
+    @patch('pptopic.lib.cv2.cvtColor')
+    @patch('pptopic.lib.cv2.resize')
+    @patch('pptopic.lib.subprocess.run')
+    @patch('pptopic.lib.lastFile')
+    def test_image_optimization_with_file_path(self, mock_last_file, mock_subprocess, 
+                                                mock_resize, mock_cvtcolor, mock_open, tmp_path):
+        """Test imageOptimization with file path input."""
+        mock_img = MagicMock()
+        mock_img.size = (100, 100)
+        mock_img.mode = 'RGB'
+        mock_open.return_value = mock_img
+        
+        mock_array = np.array([[[255, 0, 0]]])
+        mock_cvtcolor.return_value = mock_array
+        
+        mock_resized = np.array([[[255, 0, 0]]])
+        mock_resize.return_value = mock_resized
+        
+        mock_pil_img = MagicMock()
+        with patch('pptopic.lib.Image.fromarray', return_value=mock_pil_img):
+            with patch('pptopic.lib.Image.open', return_value=mock_img):
+                mock_last_file.return_value = tmp_path / "optimized.png"
+                
+                result = imageOptimization(tmp_path / "test.png")
+                
+                assert result is not None
+
+    @patch('pptopic.lib.cv2.cvtColor')
+    @patch('pptopic.lib.cv2.resize')
+    @patch('pptopic.lib.subprocess.run')
+    @patch('pptopic.lib.lastFile')
+    def test_image_optimization_with_pil_image(self, mock_last_file, mock_subprocess,
+                                               mock_resize, mock_cvtcolor, tmp_path):
+        """Test imageOptimization with PIL Image input."""
+        mock_img = MagicMock()
+        mock_img.size = (100, 100)
+        mock_img.mode = 'RGB'
+        
+        mock_array = np.array([[[255, 0, 0]]])
+        mock_cvtcolor.return_value = mock_array
+        
+        mock_resized = np.array([[[255, 0, 0]]])
+        mock_resize.return_value = mock_resized
+        
+        mock_pil_img = MagicMock()
+        with patch('pptopic.lib.Image.fromarray', return_value=mock_pil_img):
+            with patch('pptopic.lib.Image.open', return_value=mock_img):
+                mock_last_file.return_value = tmp_path / "optimized.png"
+                
+                result = imageOptimization(mock_img)
+                
+                assert result is not None
+
+    @patch('pptopic.lib.Image.open')
+    @patch('pptopic.lib.cv2.cvtColor')
+    @patch('pptopic.lib.cv2.resize')
+    @patch('pptopic.lib.subprocess.run')
+    @patch('pptopic.lib.shutil.copyfile')
+    def test_image_optimization_with_save_file(self, mock_copyfile, mock_subprocess,
+                                               mock_resize, mock_cvtcolor, mock_open, tmp_path):
+        """Test imageOptimization with saveFile parameter."""
+        mock_img = MagicMock()
+        mock_img.size = (100, 100)
+        mock_img.mode = 'RGB'
+        mock_open.return_value = mock_img
+        
+        mock_array = np.array([[[255, 0, 0]]])
+        mock_cvtcolor.return_value = mock_array
+        
+        mock_resized = np.array([[[255, 0, 0]]])
+        mock_resize.return_value = mock_resized
+        
+        mock_pil_img = MagicMock()
+        with patch('pptopic.lib.Image.fromarray', return_value=mock_pil_img):
+            with patch('pptopic.lib.lastFile') as mock_last_file:
+                mock_last_file.return_value = tmp_path / "optimized.png"
+                
+                result = imageOptimization(tmp_path / "test.png", saveFile=tmp_path / "output.png")
+                
+                assert result is None
+                mock_copyfile.assert_called_once()
+
+    @patch('pptopic.lib.Image.open')
+    @patch('pptopic.lib.cv2.cvtColor')
+    @patch('pptopic.lib.cv2.resize')
+    @patch('pptopic.lib.subprocess.run')
+    @patch('pptopic.lib.lastFile')
+    def test_image_optimization_with_max_width(self, mock_last_file, mock_subprocess,
+                                               mock_resize, mock_cvtcolor, mock_open, tmp_path):
+        """Test imageOptimization with max_width parameter."""
+        mock_img = MagicMock()
+        mock_img.size = (200, 100)
+        mock_img.mode = 'RGB'
+        mock_open.return_value = mock_img
+        
+        mock_array = np.zeros((100, 200, 3), dtype=np.uint8)
+        mock_cvtcolor.return_value = mock_array
+        
+        mock_resized = np.zeros((50, 100, 3), dtype=np.uint8)
+        mock_resize.return_value = mock_resized
+        
+        mock_pil_img = MagicMock()
+        with patch('pptopic.lib.Image.fromarray', return_value=mock_pil_img):
+            with patch('pptopic.lib.Image.open', return_value=mock_img):
+                mock_last_file.return_value = tmp_path / "optimized.png"
+                
+                result = imageOptimization(tmp_path / "test.png", max_width=100)
+                
+                mock_resize.assert_called_once()
+                assert result is not None
+
+    @patch('pptopic.lib.Image.open')
+    @patch('pptopic.lib.cv2.cvtColor')
+    @patch('pptopic.lib.cv2.resize')
+    @patch('pptopic.lib.subprocess.run')
+    @patch('pptopic.lib.lastFile')
+    def test_image_optimization_with_max_height(self, mock_last_file, mock_subprocess,
+                                                mock_resize, mock_cvtcolor, mock_open, tmp_path):
+        """Test imageOptimization with max_height parameter."""
+        mock_img = MagicMock()
+        mock_img.size = (100, 200)
+        mock_img.mode = 'RGB'
+        mock_open.return_value = mock_img
+        
+        mock_array = np.zeros((200, 100, 3), dtype=np.uint8)
+        mock_cvtcolor.return_value = mock_array
+        
+        mock_resized = np.zeros((100, 50, 3), dtype=np.uint8)
+        mock_resize.return_value = mock_resized
+        
+        mock_pil_img = MagicMock()
+        with patch('pptopic.lib.Image.fromarray', return_value=mock_pil_img):
+            with patch('pptopic.lib.Image.open', return_value=mock_img):
+                mock_last_file.return_value = tmp_path / "optimized.png"
+                
+                result = imageOptimization(tmp_path / "test.png", max_height=100)
+                
+                mock_resize.assert_called_once()
+                assert result is not None
+
+    @patch('pptopic.lib.Image.open')
+    @patch('pptopic.lib.cv2.cvtColor')
+    @patch('pptopic.lib.cv2.resize')
+    @patch('pptopic.lib.subprocess.run')
+    @patch('pptopic.lib.lastFile')
+    def test_image_optimization_with_fractional_width(self, mock_last_file, mock_subprocess,
+                                                      mock_resize, mock_cvtcolor, mock_open, tmp_path):
+        """Test imageOptimization with fractional max_width (< 1)."""
+        mock_img = MagicMock()
+        mock_img.size = (200, 100)
+        mock_img.mode = 'RGB'
+        mock_open.return_value = mock_img
+        
+        mock_array = np.zeros((100, 200, 3), dtype=np.uint8)
+        mock_cvtcolor.return_value = mock_array
+        
+        mock_resized = np.zeros((50, 100, 3), dtype=np.uint8)
+        mock_resize.return_value = mock_resized
+        
+        mock_pil_img = MagicMock()
+        with patch('pptopic.lib.Image.fromarray', return_value=mock_pil_img):
+            with patch('pptopic.lib.Image.open', return_value=mock_img):
+                mock_last_file.return_value = tmp_path / "optimized.png"
+                
+                result = imageOptimization(tmp_path / "test.png", max_width=0.5)
+                
+                mock_resize.assert_called_once()
+                assert result is not None
+
+    @patch('pptopic.lib.Image.open')
+    @patch('pptopic.lib.cv2.cvtColor')
+    @patch('pptopic.lib.subprocess.run')
+    @patch('pptopic.lib.lastFile')
+    def test_image_optimization_without_engine(self, mock_last_file, mock_subprocess,
+                                               mock_cvtcolor, mock_open, tmp_path):
+        """Test imageOptimization with engine=None."""
+        mock_img = MagicMock()
+        mock_img.size = (100, 100)
+        mock_img.mode = 'RGB'
+        mock_open.return_value = mock_img
+        
+        mock_array = np.array([[[255, 0, 0]]])
+        mock_cvtcolor.return_value = mock_array
+        
+        mock_pil_img = MagicMock()
+        with patch('pptopic.lib.Image.fromarray', return_value=mock_pil_img):
+            with patch('pptopic.lib.Image.open', return_value=mock_img):
+                mock_last_file.return_value = tmp_path / "optimized.png"
+                
+                result = imageOptimization(tmp_path / "test.png", engine=None)
+                
+                mock_subprocess.assert_not_called()
+                assert result is not None
+
+    @patch('pptopic.lib.Image.open')
+    @patch('pptopic.lib.cv2.cvtColor')
+    @patch('pptopic.lib.subprocess.run')
+    def test_image_optimization_engine_failure(self, mock_subprocess, mock_cvtcolor, mock_open):
+        """Test imageOptimization when engine subprocess fails."""
+        mock_img = MagicMock()
+        mock_img.size = (100, 100)
+        mock_img.mode = 'RGB'
+        mock_open.return_value = mock_img
+        
+        mock_array = np.array([[[255, 0, 0]]])
+        mock_cvtcolor.return_value = mock_array
+        
+        mock_subprocess.side_effect = Exception("Engine not found")
+        
+        mock_pil_img = MagicMock()
+        with patch('pptopic.lib.Image.fromarray', return_value=mock_pil_img):
+            with pytest.raises(Exception):
+                imageOptimization("test.png", engine="pngquant", engine_conf="--quality=85")