webp

go.mod

@@ -10,11 +10,18 @@ require (
 	gorm.io/gorm v1.25.1
 )
 
-require github.com/mattn/go-sqlite3 v1.14.16 // indirect
+require (
+	github.com/mattn/go-sqlite3 v1.14.16 // indirect
+	github.com/sizeofint/webp-animation v0.0.0-20190207194838-b631dc900de9 // indirect
+	golang.org/x/image v0.0.0-20211028202545-6944b10bf410 // indirect
+)
 
 require (
+	github.com/chai2010/webp v1.1.1
+	github.com/disintegration/imaging v1.6.2
 	github.com/jinzhu/inflection v1.0.0 // indirect
 	github.com/jinzhu/now v1.1.5 // indirect
+	github.com/sizeofint/gif-to-webp v0.0.0-20210224202734-e9d7ed071591
 	github.com/tencentcloud/tencentcloud-sdk-go/tencentcloud/common v1.0.669
 	github.com/tencentcloud/tencentcloud-sdk-go/tencentcloud/cvm v1.0.669
 	gopkg.in/yaml.v2 v2.4.0

go.sum

@@ -1,3 +1,7 @@
+github.com/chai2010/webp v1.1.1 h1:jTRmEccAJ4MGrhFOrPMpNGIJ/eybIgwKpcACsrTEapk=
+github.com/chai2010/webp v1.1.1/go.mod h1:0XVwvZWdjjdxpUEIf7b9g9VkHFnInUSYujwqTLEuldU=
+github.com/disintegration/imaging v1.6.2 h1:w1LecBlG2Lnp8B3jk5zSuNqd7b4DXhcjwek1ei82L+c=
+github.com/disintegration/imaging v1.6.2/go.mod h1:44/5580QXChDfwIclfc/PCwrr44amcmDAg8hxG0Ewe4=
 github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
 github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/gorilla/mux v1.8.0 h1:i40aqfkR1h2SlN9hojwV5ZA91wcXFOvkdNIeFDP5koI=
@@ -13,10 +17,20 @@ github.com/mattn/go-sqlite3 v1.14.16 h1:yOQRA0RpS5PFz/oikGwBEqvAWhWg5ufRz4ETLjwp
 github.com/mattn/go-sqlite3 v1.14.16/go.mod h1:2eHXhiwb8IkHr+BDWZGa96P6+rkvnG63S2DGjv9HUNg=
 github.com/russross/blackfriday v1.6.0 h1:KqfZb0pUVN2lYqZUYRddxF4OR8ZMURnJIG5Y3VRLtww=
 github.com/russross/blackfriday v1.6.0/go.mod h1:ti0ldHuxg49ri4ksnFxlkCfN+hvslNlmVHqNRXXJNAY=
+github.com/sizeofint/gif-to-webp v0.0.0-20210224202734-e9d7ed071591 h1:dCWBD4Xchp/XFIR/x6D2l74DtQHvIpHsmpPRHgH9oUo=
+github.com/sizeofint/gif-to-webp v0.0.0-20210224202734-e9d7ed071591/go.mod h1:IXC7KN2FEuTEISdePm37qcFyXInAh6pfW35yDjbdfOM=
+github.com/sizeofint/webp-animation v0.0.0-20190207194838-b631dc900de9 h1:i3LYMwQ0zkh/BJ47vIZN+jBYqV4/f6DFoAsW8rwV490=
+github.com/sizeofint/webp-animation v0.0.0-20190207194838-b631dc900de9/go.mod h1:/NQ8ciRuH+vxYhrFlnX70gvXBugMYQbBygCRocFgSZ4=
 github.com/tencentcloud/tencentcloud-sdk-go/tencentcloud/common v1.0.669 h1:5KKJBcemqKONBFxMdMyLMvk+TrqXaEPhqe9TrZqB3r0=
 github.com/tencentcloud/tencentcloud-sdk-go/tencentcloud/common v1.0.669/go.mod h1:7sCQWVkxcsR38nffDW057DRGk8mUjK1Ing/EFOK8s8Y=
 github.com/tencentcloud/tencentcloud-sdk-go/tencentcloud/cvm v1.0.669 h1:gc1bPO/YVfuXEIs+HbQ/gFlFjdkJjOsjm8xWqF7hPww=
 github.com/tencentcloud/tencentcloud-sdk-go/tencentcloud/cvm v1.0.669/go.mod h1:hhy13j6NKKxt/g62JZEDekJNQx3EAevnHopmwlt2tRc=
+golang.org/x/image v0.0.0-20191009234506-e7c1f5e7dbb8/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
+golang.org/x/image v0.0.0-20211028202545-6944b10bf410 h1:hTftEOvwiOq2+O8k2D5/Q7COC7k5Qcrgc2TFURJYnvQ=
+golang.org/x/image v0.0.0-20211028202545-6944b10bf410/go.mod h1:023OzeP/+EPmXeapQh35lcL3II3LrY8Ic+EFFKVhULM=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=

models/Image.go

@@ -1,10 +1,18 @@
 package models
 
 import (
+	"bytes"
 	"database/sql/driver"
 	"encoding/json"
+	"fmt"
+	"image"
+	"io/ioutil"
 	"main/configs"
 	"time"
+
+	"github.com/chai2010/webp"
+	"github.com/disintegration/imaging"
+	giftowebp "github.com/sizeofint/gif-to-webp"
 )
 
 type Image struct {
@@ -24,6 +32,56 @@ type Image struct {
 	UpdatedAt         time.Time `json:"updated_at" gorm:"autoUpdateTime"`
 }
 
+// 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) {
+	// 從絕對路徑讀原始圖片
+	data, err := ioutil.ReadFile(fmt.Sprintf("data/images/%d", img.ID))
+	if err != nil {
+		return nil, err
+	}
+	// 將原始圖片轉換為 Image
+	imageData, format, err := image.Decode(bytes.NewReader(data))
+	if err != nil {
+		return nil, err
+	}
+
+	// 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 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(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(imageData, 100)
+	}
+	switch fit {
+	case "cover":
+		return webp.EncodeRGBA(imaging.Fill(imageData, width, height, imaging.Center, imaging.Lanczos), 100)
+	case "contain":
+		return webp.EncodeRGBA(imaging.Fit(imageData, width, height, imaging.Lanczos), 100)
+	case "fill":
+		return webp.EncodeRGBA(imaging.Fill(imageData, width, height, imaging.Center, imaging.Lanczos), 100)
+	case "inside":
+		return webp.EncodeRGBA(imaging.Fit(imageData, width, height, imaging.Lanczos), 100)
+	case "outside":
+		return webp.EncodeRGBA(imaging.Fill(imageData, width, height, imaging.Center, imaging.Lanczos), 100)
+	case "scale-down":
+		return webp.EncodeRGBA(imaging.Fit(imageData, width, height, imaging.Lanczos), 100)
+	default:
+		return webp.EncodeRGBA(imaging.Resize(imageData, width, height, imaging.Lanczos), 100)
+	}
+}
+
 func init() {
 	configs.ORMDB().AutoMigrate(&Image{})
 }