如何在谷歌云存储中上传调整大小的图像？

Question

How to upload an image file in Google Cloud Storage that I already resized using 3rd party package "github.com/disintegration/imaging" ?

I tried this

Code:

f, uploadedFile, err := c.Request.FormFile("file") // image file
    // Decode the file into a image struct
     srcImg, _, err:=  image.Decode(f)

    // Resize srcImage to width = 800px preserving the aspect ratio.
    adjustedFile := imaging.Resize(srcImg, 800, 0, imaging.Lanczos)

    if err != nil {
        c.JSON(http.StatusInternalServerError, gin.H{
            "message": err.Error(),
            "error":   true,
        })
        return
    }

    defer f.Close()

    sw := storageClient.Bucket(bucket).Object(""+ callType +"/"+ yearString +"/"+ monthString +"/" + uploadedFile.Filename).NewWriter(ctx)
    
    if _, err := io.Copy(sw, adjustedFile); err != nil { // error here
        c.JSON(http.StatusInternalServerError, gin.H{
            "message": err.Error(),
            "error":   true,
        })
        return
    }

Error:

`cannot use adjustedFile (type *image.NRGBA) as type io.Reader in a`rgument to io.Copy:
    *image.NRGBA does not implement io.Reader (missing Read method)

Answer 1

Posting this as a community wiki, since It's based on @CeriseLimon's comment.

The problem is that you have to encode your image to bytes before sending it to GCS and you can do it by using the image/jpeg package, try the following code

if _, err := jpeg.Encode(sw, adjustedFile, &jpeg.Options{Quality:77}); err != nil {
    ...
}