GO语言实现批量压缩图片和水印

前段时间想做个图片站，就用手机照了很多相片，但是要一个个用ps去压缩修改尺寸太麻烦了。最后想到了用golang去实现，算是边学边练吧。其中用到了github.com/nfnt/resize这个第三方库，仅仅支持jpg图片格式。

package main
import (
    "fmt"
    "github.com/nfnt/resize"
    "image"
    "image/draw"
    "image/jpeg"
    "image/png"
    "io/ioutil"
    "log"
    "math/rand"
    "os"
    "runtime"
    "strconv"
    "strings"
    "time"
)
func main() {
    runtime.gomaxprocs(runtime.numcpu())
    cmd("data/")
    fmt.println("ok!")
}
// 执行操作
func cmd(path string) {
    files, _ := ioutil.readdir(path)
    for _, file := range files {
        if file.isdir() {
            fmt.println("目录" + file.name())
            cmd(path + file.name() + "/")
        } else {
            if strings.contains(strings.tolower(file.name()), ".jpg") {
                // 随机名称
                to := path + random_name() + ".jpg"
                origin := path + file.name()
                fmt.println("正在处理" + origin + ">>>" + to)
                cmd_resize(origin, 2048, 0, to)
                defer os.remove(origin)
            }
        }
    }
}
// 改变大小
func cmd_resize(file string, width uint, height uint, to string) {
    // 打开图片并解码
    file_origin, _ := os.open(file)
    origin, _ := jpeg.decode(file_origin)
    defer file_origin.close()
    canvas := resize.resize(width, height, origin, resize.lanczos3)
    file_out, err := os.create(to)
    if err != nil {
        log.fatal(err)
    }
    defer file_out.close()
    jpeg.encode(file_out, canvas, &jpeg.options{80})
    // cmd_watermark(to, strings.replace(to, ".jpg", "@big.jpg", 1))
    cmd_thumbnail(to, 480, 360, strings.replace(to, ".jpg", "@small.jpg", 1))
}
func cmd_thumbnail(file string, width uint, height uint, to string) {
    // 打开图片并解码
    file_origin, _ := os.open(file)
    origin, _ := jpeg.decode(file_origin)
    defer file_origin.close()
    canvas := resize.thumbnail(width, height, origin, resize.lanczos3)
    file_out, err := os.create(to)
    if err != nil {
        log.fatal(err)
    }
    defer file_out.close()
    jpeg.encode(file_out, canvas, &jpeg.options{80})
}
// 水印
func cmd_watermark(file string, to string) {
    // 打开图片并解码
    file_origin, _ := os.open(file)
    origin, _ := jpeg.decode(file_origin)
    defer file_origin.close()
    // 打开水印图并解码
    file_watermark, _ := os.open("watermark.png")
    watermark, _ := png.decode(file_watermark)
    defer file_watermark.close()
    //原始图界限
    origin_size := origin.bounds()
    //创建新图层
    canvas := image.newnrgba(origin_size)
    // 贴原始图
    draw.draw(canvas, origin_size, origin, image.zp, draw.src)
    // 贴水印图
    draw.draw(canvas, watermark.bounds().add(image.pt(30, 30)), watermark, image.zp, draw.over)
    //生成新图片
    create_image, _ := os.create(to)
    jpeg.encode(create_image, canvas, &jpeg.options{95})
    defer create_image.close()
}
// 随机生成文件名
func random_name() string {
    rand.seed(time.now().unixnano())
    return strconv.itoa(rand.int())
}

以上就是本文所述的全部内容了，希望能够对大家熟练掌握go语言有所帮助。