// [Decode] is the function that decodes the encoded image.
// [DecodeConfig] is the function that decodes just its configuration.
func RegisterFormat(name, magic string, decode func(io.Reader) (Image, error), decodeConfig func(io.Reader) (Config, error)) {
	formatsMu.Lock()
	formats, _ := atomicFormats.Load().([]format)
	atomicFormats.Store(append(formats, format{name, magic, decode, decodeConfig}))
	formatsMu.Unlock()
}

	if err != nil {
		return nil, "", err
	}
	defer f.Close()
	return image.Decode(bufio.NewReader(f))
}

func decodeConfig(filename string) (image.Config, string, error) {
	f, err := os.Open(filename)
	if err != nil {
		return image.Config{}, "", err
	}
	defer f.Close()
	return image.DecodeConfig(bufio.NewReader(f))
}

func delta(u0, u1 uint32) int {
	d := int(u0) - int(u1)
	if d < 0 {
		return -d
	}

		b, err := os.ReadFile(filepath.Join("../testdata", de.Name()))
		if err != nil {
			f.Fatalf("failed to read testdata: %s", err)
		}
		f.Add(b)
	}

	f.Fuzz(func(t *testing.T, b []byte) {
		cfg, _, err := image.DecodeConfig(bytes.NewReader(b))
		if err != nil {
			return
		}
		if cfg.Width*cfg.Height > 1e6 {
			return
		}
		img, typ, err := image.Decode(bytes.NewReader(b))
		if err != nil || typ != "png" {
			return
		}

		0xe4, 0xbd, 0x70, 0x00, 0x00, 0x00, 0x00, 0x49, 0x45, 0x4e, 0x44, 0xae, 0x42, 0x60, 0x82,
	}

	cfg, err := DecodeConfig(bytes.NewReader(src))
	if err != nil {
		t.Fatalf("DecodeConfig: %v", err)
	} else if _, _, _, alpha := cfg.ColorModel.(color.Palette)[0].RGBA(); alpha != 0 {
		t.Errorf("DecodeConfig: got %d, want 0", alpha)
	}

	img, err := Decode(bytes.NewReader(src))
	if err != nil {

		b, err := os.ReadFile(filepath.Join("../testdata", de.Name()))
		if err != nil {
			f.Fatalf("failed to read testdata: %s", err)
		}
		f.Add(b)
	}

	f.Fuzz(func(t *testing.T, b []byte) {
		cfg, _, err := image.DecodeConfig(bytes.NewReader(b))
		if err != nil {
			return
		}
		if cfg.Width*cfg.Height > 1e6 {
			return
		}
		img, typ, err := image.Decode(bytes.NewReader(b))
		if err != nil || typ != "jpeg" {
			return
		}

		b, err := os.ReadFile(filepath.Join("../testdata", de.Name()))
		if err != nil {
			f.Fatalf("failed to read testdata: %s", err)
		}
		f.Add(b)
	}

	f.Fuzz(func(t *testing.T, b []byte) {
		cfg, _, err := image.DecodeConfig(bytes.NewReader(b))
		if err != nil {
			return
		}
		if cfg.Width*cfg.Height > 1e6 {
			return
		}
		img, typ, err := image.Decode(bytes.NewReader(b))
		if err != nil || typ != "gif" {
			return
		}

	// _ "image/gif"
	// _ "image/png"
	_ "image/jpeg"
)

func Example_decodeConfig() {
	reader := base64.NewDecoder(base64.StdEncoding, strings.NewReader(data))
	config, format, err := image.DecodeConfig(reader)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println("Width:", config.Width, "Height:", config.Height, "Format:", format)
}

func Example() {

		t.Fatal("EncodeAll:", err)
	}
	encoded := buf.Bytes()
	config, err := DecodeConfig(bytes.NewReader(encoded))
	if err != nil {
		t.Fatal("DecodeConfig:", err)
	}
	g1, err := DecodeAll(bytes.NewReader(encoded))
	if err != nil {
		t.Fatal("DecodeAll:", err)
	}

	if !reflect.DeepEqual(config, g1.Config) {
		t.Errorf("DecodeConfig inconsistent with DecodeAll")
	}

			Width:      d.width,
			Height:     d.height,
		},
		BackgroundIndex: d.backgroundIndex,
	}
	return gif, nil
}

// DecodeConfig returns the global color model and dimensions of a GIF image
// without decoding the entire image.
func DecodeConfig(r io.Reader) (image.Config, error) {
	var d decoder
	if err := d.decode(r, true, false); err != nil {
		return image.Config{}, err
	}

func Decode(r io.Reader) (image.Image, error) {
	var d decoder
	return d.decode(r, false)
}

// DecodeConfig returns the color model and dimensions of a JPEG image without
// decoding the entire image.
func DecodeConfig(r io.Reader) (image.Config, error) {
	var d decoder
	if _, err := d.decode(r, true); err != nil {
		return image.Config{}, err
	}
	switch d.nComp {