Golang将image.Image转换为[] byte

Question

转换图像时遇到问题.图像转换为[]字节.问题点用虚线包裹.

image_data, err := mybucket.Get(key)

if err != nil {
    panic(err.Error())
}

// reset format of data []byte to image.Image

original_image, _, err := image.Decode(bytes.NewReader(image_data))

new_image := resize.Resize(160, 0, original_image, resize.Lanczos3)
- - - - - - - - - - - - - - - - - - - - - - - - - - -
// reset format the image.Image to data []byte here
var send_S3 []byte
var byteWriter = bufio.NewWriter(send_S3)
- - - - - - - - - - - - - - - - - - - - - - - - - -
err = jpeg.Encode(byteWriter, new_image, nil)

new_path := key + "_sm"

err = mybucket.Put(new_path, send_S3, "image/jpg", "aclstring")

基本上,我需要new_image以[]字节格式,以便我可以将它发送到我的S3存储桶.

谢谢您的帮助.

Answer 1

你想要一个bytes.Buffer,而不是bufio.Writer.当您需要写入内存的编写器时,使用bytes.Buffer.bufio.Writer只是在将数据转发给另一个编写器之前将数据缓存在内存中.

buf := new(bytes.Buffer)
err := jpeg.Encode(buf, new_image, nil)
send_s3 := buf.Bytes()

Answer 2

添加到Stephen的代码,如果你使用aws s3 go SDK来放置一个对象,你的代码将如下所示:

// create buffer
buff := new(bytes.Buffer)

// encode image to buffer
err = png.Encode(buff, new_image)
if err != nil {
    fmt.Println("failed to create buffer", err)
}

// convert buffer to reader
reader := bytes.NewReader(buf.Bytes())

// use it in `PutObjectInput`
putInput := s3.PutObjectInput{
    Bucket: aws.String("my_bucket"),
    Body:   reader,
}

// send response
resp, err := svc.PutObject(&putInput)