func CenterCrop(img *io.Reader, width, height int) ([]byte, error) {
m, _, err := image.Decode(*img)
if err != nil {
return nil, err
}
// TODO: I probably can switch to using imaging.Thumbnail here.
imgW := float64(m.Bounds().Max.X - m.Bounds().Min.X)
imgH := float64(m.Bounds().Max.Y - m.Bounds().Min.Y)
targetW := float64(width)
targetH := float64(height)
var scale float64
if imgW*targetH > targetW*imgH {
scale = targetH / imgH
} else {
scale = targetW / imgW
}
m = imaging.Resize(m, int(imgW*scale), int(imgH*scale), imaging.Lanczos)
m = imaging.CropCenter(m, width, height)
buf := new(bytes.Buffer)
jpeg.Encode(buf, m, &jpeg.Options{Quality: 95})
return buf.Bytes(), nil
}
/* resize when there is no height constraint, otherwise crop */
func (result *imageInfo) resizeOrCrop(img image.Image, width int, height int) image.Image {
var imgdata image.Image
if height == 0 {
imgdata = imaging.Resize(img, width, height, imaging.Lanczos)
} else {
imgdata = imaging.CropCenter(img, width, height)
}
result.width = imgdata.Bounds().Max.X
result.height = imgdata.Bounds().Max.Y
return imgdata
}
func (m *User) ValidateAndSetAvatar(avatarFile io.Reader, filename string) error {
var img image.Image
var err error
var ext string
var tmpFile *os.File
if tmpFile, err = ioutil.TempFile(setting.TmpPath, "uploaded-avatar-"); err != nil {
return err
}
defer os.Remove(tmpFile.Name())
defer tmpFile.Close()
if _, err = io.Copy(tmpFile, avatarFile); err != nil {
return err
}
tmpFile.Seek(0, 0)
if filename != "" {
ext = strings.ToLower(filepath.Ext(filename))
} else {
ext = utils.GetImageFormat(tmpFile)
tmpFile.Seek(0, 0)
}
if ext != ".jpg" && ext != ".jpeg" && ext != ".png" && ext != ".gif" {
return errors.New("只允许jpg, png, gif类型的图片")
}
switch ext {
case ".jpg", ".jpeg":
img, err = jpeg.Decode(tmpFile)
if err != nil {
return errors.New("无法识别此jpg文件")
}
case ".png":
img, err = png.Decode(tmpFile)
if err != nil {
return errors.New("无法识别此png文件")
}
case ".gif":
img, err = gif.Decode(tmpFile)
if err != nil {
return errors.New("无法识别此gif文件")
}
}
//crop正方形
bound := img.Bounds()
if w, h := bound.Dx(), bound.Dy(); w > h {
img = imaging.CropCenter(img, h, h)
} else if w < h {
img = imaging.CropCenter(img, w, w)
}
//制作缩略图
imgL := imaging.Resize(img, 220, 220, imaging.Lanczos)
imgM := imaging.Resize(img, 48, 48, imaging.Lanczos)
imgS := imaging.Resize(img, 24, 24, imaging.Lanczos)
uuid := strings.Replace(uuid.New(), "-", "", -1)
imgLName, imgMName, imgSName := setting.TmpPath+uuid+"-l.png", setting.TmpPath+uuid+"-m.png", setting.TmpPath+uuid+"-s.png"
errL, errM, errS := imaging.Save(imgL, imgLName), imaging.Save(imgM, imgMName), imaging.Save(imgS, imgSName)
if errL != nil || errM != nil || errS != nil {
return errors.New("无法保存头像临时文件")
}
defer os.Remove(imgLName)
defer os.Remove(imgMName)
defer os.Remove(imgSName)
_, errL = setting.AvatarFSM.PutFile(imgLName, string(uuid[0])+"/"+string(uuid[1])+"/"+uuid+"-l.png")
_, errM = setting.AvatarFSM.PutFile(imgMName, string(uuid[0])+"/"+string(uuid[1])+"/"+uuid+"-m.png")
_, errS = setting.AvatarFSM.PutFile(imgSName, string(uuid[0])+"/"+string(uuid[1])+"/"+uuid+"-s.png")
if errL != nil || errM != nil || errS != nil {
return errors.New("无法保存头像")
}
if m.Avatar != "" {
errL = setting.AvatarFSM.Delete(m.Avatar + "-l.png")
errM = setting.AvatarFSM.Delete(m.Avatar + "-m.png")
errS = setting.AvatarFSM.Delete(m.Avatar + "-s.png")
}
m.Avatar = uuid
//errL, errM, errS = setting.AvatarFSM.Delete
return nil
}
