Go实战--golang实现生成缩略图服务器(disintegration/imaging、n
生命不止,继续 go go go~~~~ 今天做一点图片处理的东西,跟大家一起学习分享。 很久之前,介绍过golang提供的关于图片的标准库: 当你search on google或百度一下的时候,你会发现很多提到了graphics-go/graphics,但是这个库不知道为何,官方好像不再提供了,很难找到了。 那也没关系,我们还有面向github编程呢!!! 温故而知新,先看一下之前的代码: package main
import "image"
import "image/color"
import "image/png"
import "os"
func main() {
// Create an 100 x 50 image
img := image.NewRGBA(image.Rect(0, 0, 100, 50))
// Draw a red dot at (2,3)
img.Set(2, 3,color.RGBA{255, 255})
// Save to out.png
f,_ := os.OpenFile("out.png",os.O_WRONLY|os.O_CREATE, 0600)
defer f.Close()
png.Encode(f,img)
}
disintegration/imaginggithub地址: Star: 1284 获取: 生成缩略图 package main
import (
"image"
"image/color"
"runtime"
"github.com/disintegration/imaging"
)
func main() {
// use all CPU cores for maximum performance
runtime.GOMAXPROCS(runtime.NumCPU())
// input files
files := []string{"1.jpg","2.jpg","3.jpg"}
// load images and make 100x100 thumbnails of them
var thumbnails []image.Image
for _,file := range files {
img,err := imaging.Open(file)
if err != nil {
panic(err)
}
thumb := imaging.Thumbnail(img,imaging.CatmullRom)
thumbnails = append(thumbnails,thumb)
}
// create a new blank image
dst := imaging.New(100*len(thumbnails),color.NRGBA{0, 0})
// paste thumbnails into the new image side by side
for i,thumb := range thumbnails {
dst = imaging.Paste(dst,thumb,image.Pt(i*100, 0))
}
// save the combined image to file
err := imaging.Save(dst,"dst.jpg")
if err != nil {
panic(err)
}
}
生成缩略图服务 关于golang中net/http可以参考: package main
import (
"fmt"
"image"
"image/color"
"image/png"
"net/http"
"runtime"
"strconv"
"strings"
"github.com/disintegration/imaging"
)
func main() {
// use all CPU cores for maximum performance
runtime.GOMAXPROCS(runtime.NumCPU())
http.HandleFunc("/",doImageHandler)
http.ListenAndServe("localhost:8080",nil)
}
func doImageHandler(w http.ResponseWriter,r *http.Request) {
fmt.Printf("%qn",strings.Split(r.URL.Path,"/"))
url := strings.Split(r.URL.Path,"/")
if len(url) != 3 {
return
}
thumbnails_size := strings.Split(url[2],"_")
if len(thumbnails_size) != 2 {
return
}
thumbnails_width,_ := strconv.Atoi(thumbnails_size[0])
thumbnails_height,_ := strconv.Atoi(thumbnails_size[1])
img,err := imaging.Open(url[1])
if err != nil {
panic(err)
}
thumb := imaging.Thumbnail(img,thumbnails_width,thumbnails_height,imaging.CatmullRom)
dst := imaging.New(thumbnails_width, 0})
dst = imaging.Paste(dst,image.Pt(0, 0))
if err != nil {
panic(err)
}
header := w.Header()
header.Add("Content-Type","image/jpeg")
png.Encode(w,dst)
}
例如,浏览器输入:http://localhost:8080/1.jpg/80_90 nfnt/resizegithub地址: Star: 1544 获取: 等比例放大缩小图片 package main
import (
"image/jpeg"
"log"
"os"
"github.com/nfnt/resize"
)
func main() {
file,err := os.Open("1.jpg")
if err != nil {
log.Fatal(err)
}
img,err := jpeg.Decode(file)
if err != nil {
log.Fatal(err)
}
file.Close()
// resize to width 1000 using Lanczos resampling
// and preserve aspect ratio
m := resize.Resize(100,img,resize.Lanczos3)
out,err := os.Create("test_resized.jpg")
if err != nil {
log.Fatal(err)
}
defer out.Close()
// write new image to file
jpeg.Encode(out,m,nil)
}
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