draw2dimg/fileutil.go
func LoadFromPngFile(filePath string) (image.Image, error) {
	// Open file
	f, err := os.OpenFile(filePath, 0, 0)
	if err != nil {
		return nil, err
	}
	defer f.Close()
	b := bufio.NewReader(f)
	img, err := png.Decode(b)
	if err != nil {
		return nil, err
	}
	return img, nil
}
func LoadFromPngFile(filePath string) (image.Image, error) {
	// Open file
	f, err := os.OpenFile(filePath, 0, 0)
	if err != nil {
		return nil, err
	}
	defer f.Close()
	b := bufio.NewReader(f)
	img, err := png.Decode(b)
	if err != nil {
		return nil, err
	}
	return img, nil
}
// LoadFromPngFile Open a png file