feat: implement unified media preview and transcription extraction

CHANGELOG.md

@@ -1,5 +1,19 @@
 # CHANGELOG - apigo.cc/go/vision
 
+## v1.0.5 (2026-05-13)
+- **高级水印系统**: 
+    - 为 `Watermark` 和 `TextWatermark` 增加旋转角度 (`angle`) 支持。
+    - 新增 `TileWatermark` 和 `TileTextWatermark` 实现全图平铺水印，支持自定义间距与角度。
+- **GIF 水印支持**: 为 `Animation` 结构增加全套水印方法，支持对动图所有帧批量添加水印。
+- **状态确认**: 确认并完善了二维码 (`QR Code`) 与条形码 (`Barcode`) 的生成与识别能力。
+
+## v1.0.4 (2026-05-13)
+- **水印系统**: 新增 `Watermark` (图片) 和 `TextWatermark` (文字) 支持九宫格位置定义与透明度。
+- **视频水印**: 扩展 `Video` 结构，支持通过 FFmpeg 一键给视频添加水印。
+- **滑块验证码**: 新增 `GenerateJigsaw` 自动生成拼图路径、带槽口底图及拼图块。
+- **动态验证码**: 新增 `GenerateGIFCaptcha` 生成抗 OCR 的动态 GIF 验证码。
+- **功能补完**: 新增 `Canvas.Clone` 方法。
+
 ## v1.0.3 (2026-05-13)
 - **性能优化**：优化 `Load` 函数，移除冗余的字符串转换，直接使用 `bytes.Reader` 进行图像解码。
 - **基准测试**：新增 `BenchmarkWarpPerspective`、`BenchmarkPHash` 和 `BenchmarkExtractPalette` 性能测试。

README.md

@@ -81,14 +81,17 @@ frame.Blur(2.0)
 vision.Save(frame, "preview.jpg")
 ```
 
-### 5. 验证码生成
+### 5. 多媒体预览与转写转码
+针对 Web 端、列表缩略图或语音转写场景的一站式优化预览。支持自动缩放并裁剪以适应指定尺寸。
 ```go
-captcha := vision.GenerateCaptcha(&vision.CaptchaOption{
+// 生成图片缩略图 (WebP, 自动填充/裁剪)
-    Length: 6,
+vision.GenerateImagePreview("photo.jpg", "thumb.webp", 200, 200)
-    Width: 200,
+
-    Height: 60,
+// 生成 4 帧动画 WebP (自动填充/裁剪, 效果动态)
-})
+vision.GenerateVideoPreview("movie.mp4", "preview.webp", 320, 180)
-vision.Save(captcha, "captcha.png")
+
+// 提取音频预览片段 (16kHz Ogg Opus, 最长 3 分钟)
+vision.GenerateAudioPreview("input.mp4", "preview.ogg")
 ```
 
 ## 🛠 API 概览

TODO.md

@@ -0,0 +1,21 @@
+# @go/vision 演进路线图 (TODO)
+
+## 🎨 1. 水印系统 (Watermarking) - [已完成]
+- [x] **图片水印**: 支持 `func (c *Canvas) Watermark(mark *Canvas, pos Position, opacity float64)`。
+- [x] **文字水印**: 支持指定字体、颜色、旋转角度的快速文字遮盖。
+- [x] **视频水印**: 封装 FFmpeg 指令，支持给视频一键添加静态水印。
+
+## 🧩 2. 交互式验证物料 (Interactive Captcha) - [已完成]
+- [x] **滑块验证码 (Slider Jigsaw)**: 
+    - [x] 自动生成拼图路径 (Puzzle Path)。
+    - [x] 输出带阴影的“拼图块”与带“槽口”的底图。
+    - [x] **开箱即用**: 输出 `JigsawResult` 结构。
+
+## 🎞 3. 动态验证码 (Dynamic GIF) - [已完成]
+- [x] **GIF 动态验证码**: 不同帧出现不同字符，并伴随背景波形干扰。
+
+## 🛠 4. 向量路径补完 (Vector)
+- [ ] **SVG Path 基础指令**: 实现 `M, L, C, Q, Z` 的解析，支持业务中复杂的异形裁剪（如滑块形状）。
+
+## 基础维护
+- [ ] 移除超纲的视频编排计划，保持 FFmpeg 仅用于帧提取与基础合成。

animation.go

@@ -83,3 +83,31 @@ func LoadGIF(path string) (*Animation, error) {
 	}
 	return anim, nil
 }
+
+// Watermark 给动画所有帧添加图片水印
+func (a *Animation) Watermark(mark *Canvas, pos Position, opacity float64, padding int, angle ...float64) {
+	for _, f := range a.Frames {
+		f.Watermark(mark, pos, opacity, padding, angle...)
+	}
+}
+
+// TileWatermark 给动画所有帧平铺图片水印
+func (a *Animation) TileWatermark(mark *Canvas, opacity float64, spacing int, angle float64) {
+	for _, f := range a.Frames {
+		f.TileWatermark(mark, opacity, spacing, angle)
+	}
+}
+
+// TextWatermark 给动画所有帧添加文字水印
+func (a *Animation) TextWatermark(text string, pos Position, style *DrawStyle, opacity float64, padding int, angle ...float64) {
+	for _, f := range a.Frames {
+		f.TextWatermark(text, pos, style, opacity, padding, angle...)
+	}
+}
+
+// TileTextWatermark 给动画所有帧平铺文字水印
+func (a *Animation) TileTextWatermark(text string, style *DrawStyle, opacity float64, spacing int, angle float64) {
+	for _, f := range a.Frames {
+		f.TileTextWatermark(text, style, opacity, spacing, angle)
+	}
+}

captcha.go

@@ -45,6 +45,41 @@ func GenerateCaptcha(opt *CaptchaOption) *Canvas {
 	return c
 }
 
+// GenerateGIFCaptcha 生成动态 GIF 验证码
+func GenerateGIFCaptcha(opt *CaptchaOption) *Animation {
+	if opt == nil {
+		opt = &CaptchaOption{Length: 4, Width: 120, Height: 40}
+	}
+	
+	const chars = "0123456789"
+	code := ""
+	for i := 0; i < opt.Length; i++ {
+		code += string(chars[rand.Int(0, len(chars)-1)])
+	}
+	anim := NewAnimation()
+	
+	// 每一帧显示不同的干扰和字符位移
+	for i := 0; i < 10; i++ {
+		c := New(opt.Width, opt.Height, "#FFFFFF")
+		c.RandBG(3)
+		
+		// 绘制字符，每一帧字符的位置都有微小抖动
+		for idx, char := range code {
+			x := float64(idx)*float64(opt.Width/opt.Length) + 5 + rand.Float(0.0, 4.0) - 2.0
+			y := float64(opt.Height/2) + 10 + rand.Float(0.0, 6.0) - 3.0
+			c.dc.Push()
+			c.dc.RotateAbout(rand.Float(0.0, 0.4)-0.2, x, y)
+			c.dc.SetColor(ParseColor(RandColor()))
+			c.dc.DrawString(string(char), x, y)
+			c.dc.Pop()
+		}
+		
+		anim.AddFrame(c, 15) // 150ms 每帧
+	}
+	
+	return anim
+}
+
 // RandText 绘制随机扭曲文本 (用于验证码)
 func (c *Canvas) RandText(text string) [][4]float64 {
 	w, h := float64(c.Width()), float64(c.Height())

jigsaw.go

@@ -0,0 +1,79 @@
+package vision
+
+import (
+	"image"
+	"image/color"
+	"image/draw"
+
+	"github.com/fogleman/gg"
+)
+
+// JigsawResult 滑块拼图结果
+type JigsawResult struct {
+	Background *Canvas // 带槽口的背景
+	Piece      *Canvas // 拼图块
+	X, Y       int     // 槽口位置
+}
+
+// GenerateJigsaw 生成滑块拼图物料
+func (c *Canvas) GenerateJigsaw(x, y, size int) *JigsawResult {
+	sw, sh := c.Width(), c.Height()
+	if x < 0 { x = 0 }
+	if y < 0 { y = 0 }
+	if x+size > sw { x = sw - size }
+	if y+size > sh { y = sh - size }
+
+	// 1. 创建背景副本并绘制槽口
+	bg := c.Clone()
+	piece := New(size, size)
+
+	// 定义拼图路径 (带有四个圆润突起/凹陷的拼图块形状)
+	drawPuzzlePath := func(dc *gg.Context, px, py, s float64) {
+		r := s / 4.0
+		dc.MoveTo(px, py)
+		dc.LineTo(px+s/2-r, py)
+		dc.QuadraticTo(px+s/2, py-r*1.5, px+s/2+r, py) // 上凸起
+		dc.LineTo(px+s, py)
+		dc.LineTo(px+s, py+s/2-r)
+		dc.QuadraticTo(px+s+r*1.5, py+s/2, px+s, py+s/2+r) // 右凸起
+		dc.LineTo(px+s, py+s)
+		dc.LineTo(px+s/2+r, py+s)
+		dc.QuadraticTo(px+s/2, py+s-r*1.5, px+s/2-r, py+s) // 下凹陷 (可以改反向)
+		dc.LineTo(px, py+s)
+		dc.LineTo(px, py+s/2+r)
+		dc.QuadraticTo(px-r*1.5, py+s/2, px, py+s/2-r) // 左凹陷
+		dc.ClosePath()
+	}
+
+	// 2. 提取拼图块内容
+	// 我们需要一个蒙版来裁剪
+	mask := gg.NewContext(sw, sh)
+	drawPuzzlePath(mask, float64(x), float64(y), float64(size))
+	mask.SetFillRule(gg.FillRuleWinding)
+	mask.Fill()
+
+	// 裁剪 Piece
+	draw.DrawMask(piece.dc.Image().(draw.Image), image.Rect(0, 0, size, size), c.dc.Image(), image.Pt(x, y), mask.Image(), image.Pt(x, y), draw.Src)
+
+	// 3. 在背景上绘制半透明槽口 (遮罩)
+	bg.dc.Push()
+	drawPuzzlePath(bg.dc, float64(x), float64(y), float64(size))
+	bg.dc.SetColor(color.RGBA{0, 0, 0, 160})
+	bg.dc.Fill()
+	bg.dc.Pop()
+
+	// 4. 给拼图块加一点描边或投影增强识别度
+	piece.dc.Push()
+	drawPuzzlePath(piece.dc, 0, 0, float64(size))
+	piece.dc.SetColor(color.RGBA{255, 255, 255, 128})
+	piece.dc.SetLineWidth(2)
+	piece.dc.Stroke()
+	piece.dc.Pop()
+
+	return &JigsawResult{
+		Background: bg,
+		Piece:      piece,
+		X:          x,
+		Y:          y,
+	}
+}

preview.go

@@ -0,0 +1,79 @@
+package vision
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+)
+
+// GenerateImagePreview 生成图片预览 (WebP)
+// 支持缩放并裁剪以填充指定尺寸 (Fill 模式)
+func GenerateImagePreview(srcPath, outPath string, width, height int) error {
+	c, err := Load(srcPath)
+	if err != nil {
+		return err
+	}
+	c.Fill(width, height)
+	return Save(c, outPath)
+}
+
+// GenerateVideoPreview 生成视频预览 (4帧动画 WebP)
+// 支持缩放并裁剪以填充指定尺寸 (Fill 模式)
+func GenerateVideoPreview(videoPath, outPath string, width, height int) error {
+	v, err := NewVideo()
+	if err != nil {
+		return err
+	}
+
+	duration, err := getVideoDuration(videoPath)
+	if err != nil {
+		return err
+	}
+
+	times := []float64{0, duration * 0.33, duration * 0.67, duration * 0.90}
+	tmpDir, _ := os.MkdirTemp("", "frames")
+	defer os.RemoveAll(tmpDir)
+
+	// 使用 ffmpeg 的 scale 和 crop 滤镜实现 Fill 效果
+	// force_original_aspect_ratio=increase 确保图片至少覆盖目标尺寸
+	// crop=w:h 裁剪中心区域
+	vf := fmt.Sprintf("scale=%d:%d:force_original_aspect_ratio=increase,crop=%d:%d", width, height, width, height)
+
+	for i, t := range times {
+		framePath := filepath.Join(tmpDir, fmt.Sprintf("frame_%d.png", i))
+		cmd := exec.Command(v.FFmpegPath, "-ss", fmt.Sprintf("%f", t), "-i", videoPath, "-frames:v", "1", "-vf", vf, framePath)
+		if err := cmd.Run(); err != nil {
+			return err
+		}
+	}
+
+	cmd := exec.Command(v.FFmpegPath, "-framerate", "1", "-i", filepath.Join(tmpDir, "frame_%d.png"), 
+		"-c:v", "libwebp", "-lossless", "0", "-quality", "70", "-loop", "0", outPath)
+	return cmd.Run()
+}
+
+// GenerateAudioPreview 提取 3 分钟内的音频用于转写/预览
+// 格式: Ogg Opus, 16kHz, 单声道
+func GenerateAudioPreview(mediaPath, outPath string) error {
+	v, err := NewVideo()
+	if err != nil {
+		return err
+	}
+	// -vn: 禁用视频
+	// -c:a libopus: 高效音频压缩
+	// -ar 16000: 采样率 16k
+	// -t 180: 最长 180 秒
+	cmd := exec.Command(v.FFmpegPath, "-i", mediaPath, "-vn", "-c:a", "libopus", "-ar", "16000", "-ac", "1", "-t", "180", outPath)
+	return cmd.Run()
+}
+
+func getVideoDuration(videoPath string) (float64, error) {
+	out, err := exec.Command("ffprobe", "-v", "error", "-show_entries", "format=duration", "-of", "default=noprint_wrappers=1:nokey=1", videoPath).Output()
+	if err != nil {
+		return 0, err
+	}
+	var duration float64
+	_, err = fmt.Sscanf(string(out), "%f", &duration)
+	return duration, err
+}

preview_test.go

@@ -0,0 +1,88 @@
+package vision
+
+import (
+	"fmt"
+	"image/color"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"testing"
+
+	"github.com/fogleman/gg"
+)
+
+func TestPreviewer(t *testing.T) {
+	// 1. 创建测试环境
+	tmpDir, err := os.MkdirTemp("", "vision_test")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	videoPath := filepath.Join(tmpDir, "test.mp4")
+	webPPath := filepath.Join(tmpDir, "preview.webp")
+	oggPath := filepath.Join(tmpDir, "preview.ogg")
+
+	// 2. 模拟生成素材 (生成 5 张纯色帧图片用于合成视频)
+	imgPattern := filepath.Join(tmpDir, "frame_%d.png")
+	for i := 0; i < 5; i++ {
+		dc := gg.NewContext(320, 240)
+		dc.SetColor(color.RGBA{uint8(i * 50), 100, 200, 255})
+		dc.Clear()
+		dc.SavePNG(fmt.Sprintf(imgPattern, i))
+	}
+
+	// 使用现有的 vision.Video 逻辑生成视频
+	v, err := NewVideo()
+	if err != nil {
+		t.Fatal(err)
+	}
+	
+	// 这里通过 ffmpeg 拼接图片并添加一个静音音频产生视频
+	err = v.CreateVideoFromImages(filepath.Join(tmpDir, "frame_%d.png"), 1, videoPath)
+	if err != nil {
+		t.Skip("FFmpeg video generation failed, skipping integration test")
+	}
+	
+	// 为测试视频添加静音音频，否则提取音频会失败
+	audioPath := filepath.Join(tmpDir, "silent.aac")
+	err = exec.Command("ffmpeg", "-f", "lavfi", "-i", "anullsrc=r=44100:cl=mono", "-t", "5", "-c:a", "aac", audioPath).Run()
+	if err == nil {
+		finalVideo := filepath.Join(tmpDir, "final.mp4")
+		exec.Command("ffmpeg", "-i", videoPath, "-i", audioPath, "-c", "copy", finalVideo).Run()
+		videoPath = finalVideo
+	}
+
+	// 3. 测试 Preview 功能
+	t.Run("GenerateImagePreview", func(t *testing.T) {
+		imgPath := filepath.Join(tmpDir, "frame_0.png")
+		previewImgPath := filepath.Join(tmpDir, "img_preview.webp")
+		err := GenerateImagePreview(imgPath, previewImgPath, 100, 100)
+		if err != nil {
+			t.Errorf("GenerateImagePreview failed: %v", err)
+		}
+		if _, err := os.Stat(previewImgPath); os.IsNotExist(err) {
+			t.Error("Image preview output not created")
+		}
+	})
+
+	t.Run("GenerateVideoPreview", func(t *testing.T) {
+		err := GenerateVideoPreview(videoPath, webPPath, 160, 120)
+		if err != nil {
+			t.Errorf("GenerateVideoPreview failed: %v", err)
+		}
+		if _, err := os.Stat(webPPath); os.IsNotExist(err) {
+			t.Error("WebP output not created")
+		}
+	})
+
+	t.Run("GenerateAudioPreview", func(t *testing.T) {
+		err := GenerateAudioPreview(videoPath, oggPath)
+		if err != nil {
+			t.Errorf("GenerateAudioPreview failed: %v", err)
+		}
+		if _, err := os.Stat(oggPath); os.IsNotExist(err) {
+			t.Error("Ogg output not created")
+		}
+	})
+}

video_ffmpeg.go

@@ -37,6 +37,21 @@ func (v *Video) ExtractFrame(videoPath string, offsetSeconds float64) (*Canvas,
 	return Load(tmpFile)
 }
 
+// WatermarkVideo 给视频添加水印
+// videoPath: 输入视频
+// markPath: 水印图片路径
+// outPath: 输出视频路径
+// pos: 水印位置 (使用 FFmpeg 语法, 如 '10:10', 'main_w-overlay_w-10:10')
+func (v *Video) WatermarkVideo(videoPath, markPath, outPath, pos string) error {
+	if pos == "" {
+		pos = "main_w-overlay_w-10:main_h-overlay_h-10" // 默认右下角
+	}
+	
+	filter := fmt.Sprintf("overlay=%s", pos)
+	cmd := exec.Command(v.FFmpegPath, "-i", videoPath, "-i", markPath, "-filter_complex", filter, "-codec:a", "copy", outPath)
+	return cmd.Run()
+}
+
 // CreateVideoFromImages 从一系列图片创建视频
 func (v *Video) CreateVideoFromImages(imagePattern string, frameRate int, outPath string) error {
 	cmd := exec.Command(v.FFmpegPath, "-framerate", fmt.Sprintf("%d", frameRate), "-i", imagePattern, "-c:v", "libx264", "-pix_fmt", "yuv420p", outPath)

vision_test.go

@@ -2,6 +2,7 @@ package vision
 
 import (
 	"image"
+	"image/color"
 	"os"
 	"testing"
 )
@@ -64,6 +65,36 @@ func TestPHash(t *testing.T) {
 	t.Logf("pHash distance: %d", dist)
 }
 
+func TestTileWatermark(t *testing.T) {
+	c := New(400, 300, "#FFFFFF")
+	c.Circle(200, 150, 50, &DrawStyle{FillColor: "#0000FF"})
+	
+	c.TileTextWatermark("CONFIDENTIAL", &DrawStyle{FillColor: "#FF0000"}, 0.2, 50, -0.785) // 45度
+	
+	err := Save(c, "test_tile_watermark.png")
+	if err != nil {
+		t.Fatalf("save tile watermark test failed: %v", err)
+	}
+	defer os.Remove("test_tile_watermark.png")
+}
+
+func TestAnimationWatermark(t *testing.T) {
+	anim := NewAnimation()
+	for i := 0; i < 5; i++ {
+		c := New(100, 100, "#FFFFFF")
+		c.Circle(float64(i*20), 50, 10, &DrawStyle{FillColor: "#00FF00"})
+		anim.AddFrame(c, 10)
+	}
+	
+	anim.TextWatermark("GO", Center, &DrawStyle{FillColor: "#000000"}, 0.5, 0)
+	
+	err := anim.SaveGIF("test_anim_watermark.gif", 0)
+	if err != nil {
+		t.Fatalf("save anim watermark failed: %v", err)
+	}
+	defer os.Remove("test_anim_watermark.gif")
+}
+
 func TestQRCode(t *testing.T) {
 	content := "https://apigo.cc"
 	c, err := GenerateQRCode(content, 200)
@@ -80,6 +111,42 @@ func TestQRCode(t *testing.T) {
 	}
 }
 
+func TestWatermark(t *testing.T) {
+	c := New(400, 300, "#EEEEEE")
+	c.Circle(200, 150, 100, &DrawStyle{FillColor: "#FFFFFF"})
+	
+	mark := New(100, 30, "#FF0000")
+	mark.dc.SetColor(color.White)
+	mark.dc.DrawString("WATERMARK", 5, 20)
+	
+	c.Watermark(mark, BottomRight, 0.5, 10)
+	
+	err := Save(c, "test_watermark.png")
+	if err != nil {
+		t.Fatalf("save watermark test failed: %v", err)
+	}
+	defer os.Remove("test_watermark.png")
+}
+
+func TestJigsaw(t *testing.T) {
+	c := New(400, 300, "#FFFFFF")
+	c.RandBG(5)
+	
+	res := c.GenerateJigsaw(150, 100, 60)
+	
+	err := Save(res.Background, "test_jigsaw_bg.png")
+	if err != nil {
+		t.Errorf("save jigsaw bg failed: %v", err)
+	}
+	err = Save(res.Piece, "test_jigsaw_piece.png")
+	if err != nil {
+		t.Errorf("save jigsaw piece failed: %v", err)
+	}
+	
+	defer os.Remove("test_jigsaw_bg.png")
+	defer os.Remove("test_jigsaw_piece.png")
+}
+
 func TestBarcode(t *testing.T) {
 	content := "12345678"
 	c, err := GenerateBarcode(content, 200, 50)

watermark.go

@@ -0,0 +1,139 @@
+package vision
+
+import (
+	"image"
+	"image/color"
+	"image/draw"
+)
+
+// Position 水印位置
+type Position int
+
+const (
+	TopLeft Position = iota
+	TopCenter
+	TopRight
+	LeftCenter
+	Center
+	RightCenter
+	BottomLeft
+	BottomCenter
+	BottomRight
+)
+
+// Watermark 给画布添加图片水印
+// mark: 水印画布
+// pos: 位置
+// opacity: 透明度 (0.0 - 1.0)
+// padding: 边距
+// angle: 旋转角度 (弧度)
+func (c *Canvas) Watermark(mark *Canvas, pos Position, opacity float64, padding int, angle ...float64) {
+	if mark == nil || opacity < 0.01 {
+		return
+	}
+
+	w, h := c.Width(), c.Height()
+	mw, mh := mark.Width(), mark.Height()
+
+	var x, y int
+	switch pos {
+	case TopLeft:
+		x, y = padding, padding
+	case TopCenter:
+		x, y = (w-mw)/2, padding
+	case TopRight:
+		x, y = w-mw-padding, padding
+	case LeftCenter:
+		x, y = padding, (h-mh)/2
+	case Center:
+		x, y = (w-mw)/2, (h-mh)/2
+	case RightCenter:
+		x, y = w-mw-padding, (h-mh)/2
+	case BottomLeft:
+		x, y = padding, h-mh-padding
+	case BottomCenter:
+		x, y = (w-mw)/2, h-mh-padding
+	case BottomRight:
+		x, y = w-mw-padding, h-mh-padding
+	}
+
+	c.dc.Push()
+	if len(angle) > 0 && angle[0] != 0 {
+		c.dc.RotateAbout(angle[0], float64(x+mw/2), float64(y+mh/2))
+	}
+
+	// 处理透明度
+	if opacity >= 0.99 {
+		c.dc.DrawImage(mark.dc.Image(), x, y)
+	} else {
+		mask := image.NewUniform(color.Alpha{uint8(255 * opacity)})
+		draw.DrawMask(c.dc.Image().(draw.Image), mark.dc.Image().Bounds().Add(image.Pt(x, y)), mark.dc.Image(), image.Point{}, mask, image.Point{}, draw.Over)
+	}
+	c.dc.Pop()
+}
+
+// TileWatermark 平铺图片水印
+// spacing: 间距
+// angle: 旋转角度 (弧度)
+func (c *Canvas) TileWatermark(mark *Canvas, opacity float64, spacing int, angle float64) {
+	if mark == nil || opacity < 0.01 {
+		return
+	}
+
+	mw, mh := mark.Width(), mark.Height()
+	w, h := c.Width(), c.Height()
+
+	stepX := mw + spacing
+	stepY := mh + spacing
+
+	for y := -mh; y < h+mh; y += stepY {
+		for x := -mw; x < w+mw; x += stepX {
+			c.dc.Push()
+			c.dc.RotateAbout(angle, float64(x+mw/2), float64(y+mh/2))
+			if opacity >= 0.99 {
+				c.dc.DrawImage(mark.dc.Image(), x, y)
+			} else {
+				mask := image.NewUniform(color.Alpha{uint8(255 * opacity)})
+				draw.DrawMask(c.dc.Image().(draw.Image), mark.dc.Image().Bounds().Add(image.Pt(x, y)), mark.dc.Image(), image.Point{}, mask, image.Point{}, draw.Over)
+			}
+			c.dc.Pop()
+		}
+	}
+}
+
+// TextWatermark 给画布添加文字水印
+func (c *Canvas) TextWatermark(text string, pos Position, style *DrawStyle, opacity float64, padding int, angle ...float64) {
+	// 创建一个临时画布来渲染文字，然后调用 Watermark
+	c.dc.Push()
+	tw, th := c.dc.MeasureString(text)
+	temp := New(int(tw)+4, int(th)+4)
+	if style != nil && style.FillColor != "" {
+		temp.dc.SetColor(ParseColor(style.FillColor))
+	} else {
+		temp.dc.SetColor(color.Black)
+	}
+	temp.dc.DrawString(text, 2, th+2)
+	
+	ang := 0.0
+	if len(angle) > 0 {
+		ang = angle[0]
+	}
+	c.Watermark(temp, pos, opacity, padding, ang)
+	c.dc.Pop()
+}
+
+// TileTextWatermark 平铺文字水印
+func (c *Canvas) TileTextWatermark(text string, style *DrawStyle, opacity float64, spacing int, angle float64) {
+	c.dc.Push()
+	tw, th := c.dc.MeasureString(text)
+	temp := New(int(tw)+4, int(th)+4)
+	if style != nil && style.FillColor != "" {
+		temp.dc.SetColor(ParseColor(style.FillColor))
+	} else {
+		temp.dc.SetColor(color.Black)
+	}
+	temp.dc.DrawString(text, 2, th+2)
+	
+	c.TileWatermark(temp, opacity, spacing, angle)
+	c.dc.Pop()
+}