golang image图片截取、剪裁、缩略图插件imaging插件的使用

golang 图片剪裁插件imaging模块官方文档：

https://github.com/disintegration/imaging

https://pkg.go.dev/github.com/disintegration/imaging#section-readme

安装

go get -u github.com/disintegration/imaging

例子一：width和height都传了值，就按传值的比例放缩

width传了值，height传0则表示宽按传值宽度拉伸，高则等比例拉伸

func Resize(img image.Image, width, height int, filter ResampleFilter) *image.NRGBA

package itying

import (
	"log"

	beego "github.com/beego/beego/v2/server/web"
	"github.com/disintegration/imaging"
)

type UserController struct {
	beego.Controller
}

func (c *UserController) Get() {
	src, err := imaging.Open("static/upload/c.png")
	if err != nil {
		log.Fatalf("failed to open image: %v", err)
	}

	//生成缩略图，尺寸150*200，并保持到为文件2.jpg
	dsc := imaging.Resize(src, 150, 200, imaging.Lanczos)

	err = imaging.Save(dsc, "static/upload/c_150_200.jpg")

	c.Ctx.WriteString("生成图片成功")
}

最终效果 原图

生成后的图片

例子2：生成缩略图，尺寸宽100,高传0表示等比例放缩

package itying

import (
	"log"

	beego "github.com/beego/beego/v2/server/web"
	"github.com/disintegration/imaging"
)

type UserController struct {
	beego.Controller
}

func (c *UserController) Get() {
	src, err := imaging.Open("static/upload/c.png")
	if err != nil {
		log.Fatalf("failed to open image: %v", err)
	}

	//生成缩略图，尺寸宽100,高传0表示等比例放缩
	//最后缩略图尺寸为100*133
	dsc := imaging.Resize(src, 100, 0, imaging.Lanczos)

	err = imaging.Save(dsc, "static/upload/c_150_200.jpg")

	c.Ctx.WriteString("用户控制器")
}

原图

剪裁后的图

例子3：生成缩略图 从中间开始截取 imaging.Center,imaging.Lanczos

package itying

import (
	"log"

	beego "github.com/beego/beego/v2/server/web"
	"github.com/disintegration/imaging"
)

type UserController struct {
	beego.Controller
}

func (c *UserController) Get() {
	src, err := imaging.Open("static/upload/c.png")
	if err != nil {
		log.Fatalf("failed to open image: %v", err)
	}

	//生成缩略图，从中间截取
	//imaging.Center, imaging.Lanczos

	dsc := imaging.Fill(src, 120, 120, imaging.Center, imaging.Lanczos)

	err = imaging.Save(dsc, "static/upload/c_100_100.jpg")

	c.Ctx.WriteString("用户控制器")
}

原图

golang剪裁后的图片