code: func getImageDimensionFromReader(rdr io.Reader) (int, int, error) {
  	image, _, err := image.DecodeConfig(rdr)
  	if err != nil {
  		return 0, 0, err
  	}
  	return image.Width, image.Height, nil
  }
docs: // getImageDimensionFromReader return image dimension , types is .jpg and .png