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cloudreve/pkg/thumb/image.go

155 lines
3.7 KiB

package thumb
import (
"errors"
"fmt"
"image"
"image/gif"
"image/jpeg"
"image/png"
"io"
"path/filepath"
"strings"
model "github.com/cloudreve/Cloudreve/v3/models"
"github.com/cloudreve/Cloudreve/v3/pkg/util"
//"github.com/nfnt/resize"
"golang.org/x/image/draw"
)
// Thumb 缩略图
type Thumb struct {
src image.Image
ext string
}
// NewThumbFromFile 从文件数据获取新的Thumb对象
// 尝试通过文件名name解码图像
func NewThumbFromFile(file io.Reader, name string) (*Thumb, error) {
ext := strings.ToLower(filepath.Ext(name))
// 无扩展名时
if len(ext) == 0 {
return nil, errors.New("未知的图像类型")
}
var err error
var img image.Image
switch ext[1:] {
case "jpg":
img, err = jpeg.Decode(file)
case "jpeg":
img, err = jpeg.Decode(file)
case "gif":
img, err = gif.Decode(file)
case "png":
img, err = png.Decode(file)
default:
return nil, errors.New("unknown image format")
}
if err != nil {
return nil, err
}
return &Thumb{
src: img,
ext: ext[1:],
}, nil
}
// GetThumb 生成给定最大尺寸的缩略图
func (image *Thumb) GetThumb(width, height uint) {
//image.src = resize.Thumbnail(width, height, image.src, resize.Lanczos3)
image.src = Thumbnail(width, height, image.src)
}
// GetSize 获取图像尺寸
func (image *Thumb) GetSize() (int, int) {
b := image.src.Bounds()
return b.Max.X, b.Max.Y
}
// Save 保存图像到给定路径
func (image *Thumb) Save(path string) (err error) {
out, err := util.CreatNestedFile(path)
if err != nil {
return err
}
defer out.Close()
switch model.GetSettingByNameWithDefault("thumb_encode_method", "jpg") {
case "png":
err = png.Encode(out, image.src)
default:
err = jpeg.Encode(out, image.src, &jpeg.Options{Quality: model.GetIntSetting("thumb_encode_quality", 85)})
}
return err
}
// Thumbnail will downscale provided image to max width and height preserving
// original aspect ratio and using the interpolation function interp.
// It will return original image, without processing it, if original sizes
// are already smaller than provided constraints.
func Thumbnail(maxWidth, maxHeight uint, img image.Image) image.Image {
origBounds := img.Bounds()
origWidth := uint(origBounds.Dx())
origHeight := uint(origBounds.Dy())
newWidth, newHeight := origWidth, origHeight
// Return original image if it have same or smaller size as constraints
if maxWidth >= origWidth && maxHeight >= origHeight {
return img
}
// Preserve aspect ratio
if origWidth > maxWidth {
newHeight = uint(origHeight * maxWidth / origWidth)
if newHeight < 1 {
newHeight = 1
}
newWidth = maxWidth
}
if newHeight > maxHeight {
newWidth = uint(newWidth * maxHeight / newHeight)
if newWidth < 1 {
newWidth = 1
}
newHeight = maxHeight
}
return Resize(newWidth, newHeight, img)
}
func Resize(newWidth, newHeight uint, img image.Image) image.Image {
// Set the expected size that you want:
dst := image.NewRGBA(image.Rect(0, 0, int(newWidth), int(newHeight)))
// Resize:
draw.BiLinear.Scale(dst, dst.Rect, img, img.Bounds(), draw.Src, nil)
return dst
}
// CreateAvatar 创建头像
func (image *Thumb) CreateAvatar(uid uint) error {
// 读取头像相关设定
savePath := util.RelativePath(model.GetSettingByName("avatar_path"))
s := model.GetIntSetting("avatar_size_s", 50)
m := model.GetIntSetting("avatar_size_m", 130)
l := model.GetIntSetting("avatar_size_l", 200)
// 生成头像缩略图
src := image.src
for k, size := range []int{s, m, l} {
//image.src = resize.Resize(uint(size), uint(size), src, resize.Lanczos3)
image.src = Resize(uint(size), uint(size), src)
err := image.Save(filepath.Join(savePath, fmt.Sprintf("avatar_%d_%d.png", uid, k)))
if err != nil {
return err
}
}
return nil
}