无损压缩GIF

bin/main.go

@@ -18,17 +18,61 @@ import (
 )
 
 func init() {
-	// 设置日志格式
 	log.SetFlags(log.Ldate | log.Ltime | log.Lshortfile)
 }
 
-// 实现一个 web api 服务(获取指定尺寸的图片)
+// string 转换为 int, 如果转换失败则返回默认值
+func stringToInt(str string, defaultValue int) int {
+	if str == "" {
+		return defaultValue
+	}
+	value, err := strconv.Atoi(str)
+	if err != nil {
+		return defaultValue
+	}
+	return value
+}
+
 func main() {
 	runtime.GOMAXPROCS(runtime.NumCPU())
-	models.GetMysql() // 测试连接数据库
+
+	var mysqlConnection models.MysqlConnection
+	mysqlConnection.Init()
+
+	// 直接走 CDN 的请求不缓存本地, 因此直接使用参数
+	http.HandleFunc("/webp/", func(w http.ResponseWriter, r *http.Request) {
+		log.Println(r.Method, r.URL.Path)
+		// URL 格式: /img/{id}.{格式}?width=320&height=320&fit=cover
+		reg := regexp.MustCompile(`^/webp/([0-9a-zA-Z]+).(jpg|jpeg|png|webp)$`)
+		matches := reg.FindStringSubmatch(r.URL.Path)
+		if len(matches) != 3 {
+			log.Println("URL 格式错误", matches)
+			w.WriteHeader(http.StatusNotFound)
+			return
+		}
+
+		id, format, width, height, fit := matches[1], matches[2], stringToInt(r.URL.Query().Get("width"), 0), stringToInt(r.URL.Query().Get("height"), 0), r.URL.Query().Get("fit")
+		content, err := mysqlConnection.GetImageContent(id)
+		if err != nil {
+			log.Println("获取图片失败", format, err)
+			w.WriteHeader(http.StatusBadRequest)
+		}
+
+		var img models.Image
+		img.Init(content)
+
+		data, err := img.ToWebP(width, height, fit)
+		if err != nil {
+			log.Println("转换图片失败", err)
+			w.WriteHeader(http.StatusBadRequest)
+		}
+
+		w.Header().Set("Content-Type", "image/webp")
+		w.Header().Set("Cache-Control", "max-age=31536000")
+		w.Write(data)
+	})
 
 	http.HandleFunc("/img/", func(w http.ResponseWriter, r *http.Request) {
-
 		// URL 格式: /img/{id}-{version}@{倍图}{宽度}.{格式}
 		reg := regexp.MustCompile(`^/img/([0-9a-zA-Z]+)-([0-9a-zA-Z]+)@([0-9]{1,4})x([0-9]{1,4}).(jpg|jpeg|png|webp)$`)
 		matches := reg.FindStringSubmatch(r.URL.Path)

models/config.go

@@ -28,7 +28,7 @@ func 生成配置文件() {
 	viper.Set("mysql.charset", "utf8mb4")
 	viper.Set("mysql.maxOpenConns", 100)
 
-	viper.Set("oss.host", "")
+	viper.Set("oss.endpoint", "")
-	viper.Set("oss.accessId", "")
+	viper.Set("oss.accessID", "")
 	viper.Set("oss.accessKey", "")
 }

models/image.go

@@ -0,0 +1,121 @@
+package models
+
+import (
+	"image"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"regexp"
+
+	"github.com/chai2010/webp"
+	"github.com/disintegration/imaging"
+	giftowebp "github.com/sizeofint/gif-to-webp"
+)
+
+// Image is a struct that contains the information of an image
+type Image struct {
+	image  image.Image
+	format string
+	data   []byte
+}
+
+// 初始化图片
+func (img *Image) Init(content string) {
+	if len(regexp.MustCompile(`image.gameuiux.cn`).FindStringSubmatch(content)) > 0 {
+		key := regexp.MustCompile(`^https?://image.gameuiux.cn/`).ReplaceAllString(content, "")
+
+		// 从OSS中读取图片
+		bucket := GetBucket("gameui-image2")
+		body, err := bucket.GetObject(key)
+		if err != nil {
+			log.Println("读取图片失败", err)
+			return
+		}
+		defer body.Close()
+
+		// 判断图片格式是否为 gif 或 GIF
+		if len(regexp.MustCompile(`\.gif$`).FindStringSubmatch(key)) > 0 {
+			img.format = "gif"
+			img.data, err = ioutil.ReadAll(body)
+			if err != nil {
+				log.Println("读取图片失败", err)
+				return
+			}
+			return
+		}
+
+		// 将文件解码为 image.Image
+		img.image, img.format, err = image.Decode(body)
+		if err != nil {
+			log.Println("解码图像失败", err)
+			return
+		}
+		return
+	} else {
+		log.Println("直接从网络下载图片:", content)
+		resp, err := http.Get(content)
+		if err != nil {
+			log.Println("下载图片失败", err)
+			return
+		}
+		defer resp.Body.Close()
+
+		// 判断图片格式是否为 gif 或 GIF
+		if len(regexp.MustCompile(`\.gif$`).FindStringSubmatch(content)) > 0 {
+			img.format = "gif"
+			img.data, err = ioutil.ReadAll(resp.Body)
+			if err != nil {
+				log.Println("读取图片失败", err)
+				return
+			}
+			println("数据长度:", len(img.data))
+			return
+		}
+
+		// 将文件解码为 image.Image
+		img.image, img.format, err = image.Decode(resp.Body)
+		if err != nil {
+			log.Println("解码图像失败", err)
+			return
+		}
+	}
+}
+
+// 将图片输出为指定尺寸的 webp 格式(默认使用 Lanczos 缩放算法)
+func (img *Image) ToWebP(width int, height int, fit string) ([]byte, error) {
+	// 如果原图是GIF格式的动态图片，直接不作尺寸处理，直接转换为webp格式
+	if img.format == "gif" {
+		converter := giftowebp.NewConverter()
+		converter.LoopCompatibility = true   // 是否兼容循环动画
+		converter.WebPConfig.SetLossless(1)  // 0 有损压缩 1无损压缩
+		converter.WebPConfig.SetMethod(6)    // 压缩速度 0-6 0最快 6质量最好
+		converter.WebPConfig.SetQuality(100) // 压缩质量 0-100
+		converter.WebPAnimEncoderOptions.SetKmin(9)
+		converter.WebPAnimEncoderOptions.SetKmax(17)
+		return converter.Convert(img.data)
+	}
+	// 如果指定了宽高却没有指定fit, 则默认fit为cover
+	if width != 0 && height != 0 && fit == "" {
+		fit = "cover"
+	}
+	// 如果未指定宽高和fit, 则不缩放图片直接返回webp
+	if width == 0 && height == 0 && fit == "" {
+		return webp.EncodeRGBA(img.image, 100)
+	}
+	switch fit {
+	case "cover":
+		return webp.EncodeRGBA(imaging.Fill(img.image, width, height, imaging.Center, imaging.Lanczos), 100)
+	case "contain":
+		return webp.EncodeRGBA(imaging.Fit(img.image, width, height, imaging.Lanczos), 100)
+	case "fill":
+		return webp.EncodeRGBA(imaging.Fill(img.image, width, height, imaging.Center, imaging.Lanczos), 100)
+	case "inside":
+		return webp.EncodeRGBA(imaging.Fit(img.image, width, height, imaging.Lanczos), 100)
+	case "outside":
+		return webp.EncodeRGBA(imaging.Fill(img.image, width, height, imaging.Center, imaging.Lanczos), 100)
+	case "scale-down":
+		return webp.EncodeRGBA(imaging.Fit(img.image, width, height, imaging.Lanczos), 100)
+	default:
+		return webp.EncodeRGBA(imaging.Resize(img.image, width, height, imaging.Lanczos), 100)
+	}
+}

models/mysql.go

@@ -8,7 +8,12 @@ import (
 	_ "github.com/go-sql-driver/mysql"
 )
 
-func GetMysql() {
+type MysqlConnection struct {
+	db *sql.DB
+}
+
+// 初始化数据库连接
+func (m *MysqlConnection) Init() (err error) {
 	viper := Viper // 从 models/config.go 中获取 viper 对象
 	user := viper.Get("mysql.user").(string)
 	password := viper.Get("mysql.password").(string)
@@ -16,29 +21,17 @@ func GetMysql() {
 	port := viper.Get("mysql.port").(int)
 	database := viper.Get("mysql.database").(string)
 	sqlconf := user + ":" + password + "@tcp(" + host + ":" + strconv.Itoa(port) + ")/" + database + "?charset=utf8mb4&parseTime=True&loc=Local"
-
+	m.db, err = sql.Open("mysql", sqlconf) // 连接数据库
-	// 连接数据库
-	db, err := sql.Open("mysql", sqlconf)
 	if err != nil {
 		log.Println("连接数据库失败", err)
 		return
 	}
-
-	// 从 web_images 表读取图片 id, version, width, height, format
-	rows, err := db.Query("SELECT id, width, height, content FROM web_images WHERE id = 8888")
-	if err != nil {
-		log.Println("查询数据库失败", err)
 	return
 }
-	defer rows.Close()
 
-	// 遍历查询结果
+// 根据 id 获取图片的 content
-	for rows.Next() {
+func (m *MysqlConnection) GetImageContent(id string) (key string, err error) {
-		var id, width, height, content string
+	var content string
-		if err = rows.Scan(&id, &width, &height, &content); err != nil {
+	err = m.db.QueryRow("SELECT content FROM web_images WHERE id=" + id).Scan(&content)
-			log.Println("读取数据库失败", err)
+	return content, err
-			return
-		}
-		log.Println(id, width, height, content)
-	}
 }

models/resnet.go

@@ -1,55 +0,0 @@
-package models
-
-import (
-	//"gocv.io/x/gocv"
-	//"github.com/xuyu/gotool/torch"
-	"fmt"
-
-	"github.com/wangkuiyi/gotorch"
-)
-
-func init() {
-	// 模型文件地址: https://download.pytorch.org/models/resnet50-19c8e357.pth
-	// 模型地址: "/home/satori/webp/data/resnet-50.t7"
-
-	tensor := gotorch.Load("/home/satori/webp/data/resnet-50.t7")
-	fmt.Println(tensor)
-
-	//model := torch.NewModel()
-	//err := model.ReadFromFile("/home/satori/webp/data/resnet-50.t7")
-	//if err != nil {
-	//	panic(err)
-	//}
-
-	/**
-	t7 := "/home/satori/webp/data/resnet-50.t7"
-	// 加载t7格式的模型
-	model := gocv.ReadNetFromTorch(t7)
-
-	if model.Empty() {
-		panic("Failed to load model")
-	}
-
-	fmt.Println("==============================")
-	img := gocv.IMRead("data/test.jpeg", gocv.IMReadColor)
-	if img.Empty() {
-		panic("Failed to read image")
-	}
-
-	fmt.Println("==============================")
-	inputBlob := gocv.BlobFromImage(img, 1.0, image.Pt(224, 224), gocv.NewScalar(0, 0, 0, 0), true, false)
-	defer inputBlob.Close()
-
-	fmt.Println("==============================")
-	model.SetInput(inputBlob, "input")
-	outputBlob := model.Forward("output")
-	defer outputBlob.Close()
-
-	fmt.Println("==============================")
-	features := outputBlob.Reshape(1, 1)
-	defer features.Close()
-
-	fmt.Println("==============================")
-	fmt.Println(features.ToBytes())
-	**/
-}