go/src/image/png/paeth_test.go

func slowAbs(x int) int { … }

// slowPaeth is a slow but simple implementation of the Paeth function.
// It is a straight port of the sample code in the PNG spec, section 9.4.
func slowPaeth(a, b, c uint8) uint8 { … }

// slowFilterPaeth is a slow but simple implementation of func filterPaeth.
func slowFilterPaeth(cdat, pdat []byte, bytesPerPixel int) { … }

func TestPaeth(t *testing.T) { … }

func BenchmarkPaeth(b *testing.B) { … }

func TestPaethDecode(t *testing.T) { … }