go-fastdfs/server/http_img_resize.go

package server

import (
	"bytes"
	"fmt"
	"image"
	"image/jpeg"
	"image/png"
	"io"
	"net/http"
	"os"

	"github.com/nfnt/resize"
	log "github.com/sjqzhang/seelog"
)

func (c *Server) ResizeImageByBytes(w http.ResponseWriter, data []byte, width, height uint) {
	var (
		img     image.Image
		err     error
		imgType string
	)
	reader := bytes.NewReader(data)
	img, imgType, err = image.Decode(reader)
	if err != nil {
		log.Error(err)
		return
	}
	fmt.Println(width, height)
	img = resize.Resize(width, height, img, resize.Lanczos3)
	if imgType == "jpg" || imgType == "jpeg" {
		jpeg.Encode(w, img, nil)
	} else if imgType == "png" {
		png.Encode(w, img)
	} else {
		w.Write(data)
	}
}

func (c *Server) ResizeImage(w http.ResponseWriter, fullpath string, width, height uint) {
	var (
		img     image.Image
		err     error
		imgType string
		file    *os.File
	)
	file, err = os.Open(fullpath)
	if err != nil {
		log.Error(err)
		return
	}
	img, imgType, err = image.Decode(file)
	if err != nil {
		log.Error(err)
		return
	}
	file.Close()
	img = resize.Resize(width, height, img, resize.Lanczos3)
	if imgType == "jpg" || imgType == "jpeg" {
		jpeg.Encode(w, img, nil)
	} else if imgType == "png" {
		png.Encode(w, img)
	} else {
		file.Seek(0, 0)
		io.Copy(w, file)
	}
}