Convert base64 string to JPG

Question

I am getting the image as base64 string ( dataurl ), Below is my function that converts the dataurl into the image,

Now if the

Answer 1

You're passing your io.Reader to png.Decode(), which begins consuming the reader, only to discover that the input is not a valid PNG, so returns an error.

Then your partly-consumed reader is passed to jpeg.Decode(), which reads the data not yet read, which is not a valid JPEG, and returns the error you observe.

You need to create a new reader for each decoder:

pngI, errPng := png.Decode(bytes.NewReader(unbased))

// ...

jpgI, errJpg := jpeg.Decode(bytes.NewReader(unbased))

Or better yet, consider the MIME type, and only call the proper decoder:

switch strings.TrimSuffix(image[5:coI], ";base64") {
case "image/png":
    pngI, err = png.Decode(res)
    // ...
case "image/jpeg":
    jpgI, err = jpeg.Decode(res)
    // ...
}