golang-image/tiff/reader_test.go

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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package tiff
import (
"bytes"
"encoding/binary"
"encoding/hex"
"errors"
"image"
"io/ioutil"
"os"
"strings"
"testing"
_ "image/png"
)
const testdataDir = "../testdata/"
// Read makes *buffer implements io.Reader, so that we can pass one to Decode.
func (*buffer) Read([]byte) (int, error) {
panic("unimplemented")
}
func load(name string) (image.Image, error) {
f, err := os.Open(testdataDir + name)
if err != nil {
return nil, err
}
defer f.Close()
img, _, err := image.Decode(f)
if err != nil {
return nil, err
}
return img, nil
}
// TestNoRPS tests decoding an image that has no RowsPerStrip tag. The tag is
// mandatory according to the spec but some software omits it in the case of a
// single strip.
func TestNoRPS(t *testing.T) {
_, err := load("no_rps.tiff")
if err != nil {
t.Fatal(err)
}
}
// TestNoCompression tests decoding an image that has no Compression tag. This
// tag is mandatory, but most tools interpret a missing value as no
// compression.
func TestNoCompression(t *testing.T) {
_, err := load("no_compress.tiff")
if err != nil {
t.Fatal(err)
}
}
// TestUnpackBits tests the decoding of PackBits-encoded data.
func TestUnpackBits(t *testing.T) {
var unpackBitsTests = []struct {
compressed string
uncompressed string
}{{
// Example data from Wikipedia.
"\xfe\xaa\x02\x80\x00\x2a\xfd\xaa\x03\x80\x00\x2a\x22\xf7\xaa",
"\xaa\xaa\xaa\x80\x00\x2a\xaa\xaa\xaa\xaa\x80\x00\x2a\x22\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa",
}}
for _, u := range unpackBitsTests {
buf, err := unpackBits(strings.NewReader(u.compressed))
if err != nil {
t.Fatal(err)
}
if string(buf) != u.uncompressed {
t.Fatalf("unpackBits: want %x, got %x", u.uncompressed, buf)
}
}
}
func TestShortBlockData(t *testing.T) {
b, err := ioutil.ReadFile("../testdata/bw-uncompressed.tiff")
if err != nil {
t.Fatal(err)
}
// The bw-uncompressed.tiff image is a 153x55 bi-level image. This is 1 bit
// per pixel, or 20 bytes per row, times 55 rows, or 1100 bytes of pixel
// data. 1100 in hex is 0x44c, or "\x4c\x04" in little-endian. We replace
// that byte count (StripByteCounts-tagged data) by something less than
// that, so that there is not enough pixel data.
old := []byte{0x4c, 0x04}
new := []byte{0x01, 0x01}
i := bytes.Index(b, old)
if i < 0 {
t.Fatal(`could not find "\x4c\x04" byte count`)
}
if bytes.Contains(b[i+len(old):], old) {
t.Fatal(`too many occurrences of "\x4c\x04"`)
}
b[i+0] = new[0]
b[i+1] = new[1]
if _, err = Decode(bytes.NewReader(b)); err == nil {
t.Fatal("got nil error, want non-nil")
}
}
func TestDecodeInvalidDataType(t *testing.T) {
b, err := ioutil.ReadFile("../testdata/bw-uncompressed.tiff")
if err != nil {
t.Fatal(err)
}
// off is the offset of the ImageWidth tag. It is the offset of the overall
// IFD block (0x00000454), plus 2 for the uint16 number of IFD entries, plus 12
// to skip the first entry.
const off = 0x00000454 + 2 + 12*1
if v := binary.LittleEndian.Uint16(b[off : off+2]); v != tImageWidth {
t.Fatal(`could not find ImageWidth tag`)
}
binary.LittleEndian.PutUint16(b[off+2:], uint16(len(lengths))) // invalid datatype
if _, err = Decode(bytes.NewReader(b)); err == nil {
t.Fatal("got nil error, want non-nil")
}
}
func compare(t *testing.T, img0, img1 image.Image) {
b0 := img0.Bounds()
b1 := img1.Bounds()
if b0.Dx() != b1.Dx() || b0.Dy() != b1.Dy() {
t.Fatalf("wrong image size: want %s, got %s", b0, b1)
}
x1 := b1.Min.X - b0.Min.X
y1 := b1.Min.Y - b0.Min.Y
for y := b0.Min.Y; y < b0.Max.Y; y++ {
for x := b0.Min.X; x < b0.Max.X; x++ {
c0 := img0.At(x, y)
c1 := img1.At(x+x1, y+y1)
r0, g0, b0, a0 := c0.RGBA()
r1, g1, b1, a1 := c1.RGBA()
if r0 != r1 || g0 != g1 || b0 != b1 || a0 != a1 {
t.Fatalf("pixel at (%d, %d) has wrong color: want %v, got %v", x, y, c0, c1)
}
}
}
}
// TestDecode tests that decoding a PNG image and a TIFF image result in the
// same pixel data.
func TestDecode(t *testing.T) {
img0, err := load("video-001.png")
if err != nil {
t.Fatal(err)
}
img1, err := load("video-001.tiff")
if err != nil {
t.Fatal(err)
}
img2, err := load("video-001-strip-64.tiff")
if err != nil {
t.Fatal(err)
}
img3, err := load("video-001-tile-64x64.tiff")
if err != nil {
t.Fatal(err)
}
img4, err := load("video-001-16bit.tiff")
if err != nil {
t.Fatal(err)
}
compare(t, img0, img1)
compare(t, img0, img2)
compare(t, img0, img3)
compare(t, img0, img4)
}
// TestDecodeLZW tests that decoding a PNG image and a LZW-compressed TIFF
// image result in the same pixel data.
func TestDecodeLZW(t *testing.T) {
img0, err := load("blue-purple-pink.png")
if err != nil {
t.Fatal(err)
}
img1, err := load("blue-purple-pink.lzwcompressed.tiff")
if err != nil {
t.Fatal(err)
}
compare(t, img0, img1)
}
// TestDecodeTagOrder tests that a malformed image with unsorted IFD entries is
// correctly rejected.
func TestDecodeTagOrder(t *testing.T) {
data, err := ioutil.ReadFile("../testdata/video-001.tiff")
if err != nil {
t.Fatal(err)
}
// Swap the first two IFD entries.
ifdOffset := int64(binary.LittleEndian.Uint32(data[4:8]))
for i := ifdOffset + 2; i < ifdOffset+14; i++ {
data[i], data[i+12] = data[i+12], data[i]
}
if _, _, err := image.Decode(bytes.NewReader(data)); err == nil {
t.Fatal("got nil error, want non-nil")
}
}
// TestDecompress tests that decoding some TIFF images that use different
// compression formats result in the same pixel data.
func TestDecompress(t *testing.T) {
var decompressTests = []string{
"bw-uncompressed.tiff",
"bw-deflate.tiff",
"bw-packbits.tiff",
}
var img0 image.Image
for _, name := range decompressTests {
img1, err := load(name)
if err != nil {
t.Fatalf("decoding %s: %v", name, err)
}
if img0 == nil {
img0 = img1
continue
}
compare(t, img0, img1)
}
}
func replace(src []byte, find, repl string) ([]byte, error) {
removeSpaces := func(r rune) rune {
if r != ' ' {
return r
}
return -1
}
f, err := hex.DecodeString(strings.Map(removeSpaces, find))
if err != nil {
return nil, err
}
r, err := hex.DecodeString(strings.Map(removeSpaces, repl))
if err != nil {
return nil, err
}
dst := bytes.Replace(src, f, r, 1)
if bytes.Equal(dst, src) {
return nil, errors.New("replacement failed")
}
return dst, nil
}
// TestZeroBitsPerSample tests that an IFD with a bitsPerSample of 0 does not
// cause a crash.
// Issue 10711.
func TestZeroBitsPerSample(t *testing.T) {
b0, err := ioutil.ReadFile(testdataDir + "bw-deflate.tiff")
if err != nil {
t.Fatal(err)
}
// Mutate the loaded image to have the problem.
// 02 01: tag number (tBitsPerSample)
// 03 00: data type (short, or uint16)
// 01 00 00 00: count
// ?? 00 00 00: value (1 -> 0)
b1, err := replace(b0,
"02 01 03 00 01 00 00 00 01 00 00 00",
"02 01 03 00 01 00 00 00 00 00 00 00",
)
if err != nil {
t.Fatal(err)
}
_, err = Decode(bytes.NewReader(b1))
if err == nil {
t.Fatal("Decode with 0 bits per sample: got nil error, want non-nil")
}
}
// TestTileTooBig tests that we do not panic when a tile is too big compared to
// the data available.
// Issue 10712
func TestTileTooBig(t *testing.T) {
b0, err := ioutil.ReadFile(testdataDir + "video-001-tile-64x64.tiff")
if err != nil {
t.Fatal(err)
}
// Mutate the loaded image to have the problem.
//
// 42 01: tag number (tTileWidth)
// 03 00: data type (short, or uint16)
// 01 00 00 00: count
// xx 00 00 00: value (0x40 -> 0x44: a wider tile consumes more data
// than is available)
b1, err := replace(b0,
"42 01 03 00 01 00 00 00 40 00 00 00",
"42 01 03 00 01 00 00 00 44 00 00 00",
)
if err != nil {
t.Fatal(err)
}
// Turn off the predictor, which makes it possible to hit the
// place with the defect. Without this patch to the image, we run
// out of data too early, and do not hit the part of the code where
// the original panic was.
//
// 3d 01: tag number (tPredictor)
// 03 00: data type (short, or uint16)
// 01 00 00 00: count
// xx 00 00 00: value (2 -> 1: 2 = horizontal, 1 = none)
b2, err := replace(b1,
"3d 01 03 00 01 00 00 00 02 00 00 00",
"3d 01 03 00 01 00 00 00 01 00 00 00",
)
if err != nil {
t.Fatal(err)
}
_, err = Decode(bytes.NewReader(b2))
if err == nil {
t.Fatal("did not expect nil error")
}
}
// TestZeroSizedImages tests that decoding does not panic when image dimensions
// are zero, and returns a zero-sized image instead.
// Issue 10393.
func TestZeroSizedImages(t *testing.T) {
testsizes := []struct {
w, h int
}{
{0, 0},
{1, 0},
{0, 1},
{1, 1},
}
for _, r := range testsizes {
img := image.NewRGBA(image.Rect(0, 0, r.w, r.h))
var buf bytes.Buffer
if err := Encode(&buf, img, nil); err != nil {
t.Errorf("encode w=%d h=%d: %v", r.w, r.h, err)
continue
}
if _, err := Decode(&buf); err != nil {
t.Errorf("decode w=%d h=%d: %v", r.w, r.h, err)
}
}
}
// TestLargeIFDEntry tests that a large IFD entry does not cause Decode to
// panic.
// Issue 10596.
func TestLargeIFDEntry(t *testing.T) {
testdata := "II*\x00\x08\x00\x00\x00\f\x000000000000" +
"00000000000000000000" +
"00000000000000000000" +
"00000000000000000000" +
"00000000000000\x17\x01\x04\x00\x01\x00" +
"\x00\xc0000000000000000000" +
"00000000000000000000" +
"00000000000000000000" +
"000000"
_, err := Decode(strings.NewReader(testdata))
if err == nil {
t.Fatal("Decode with large IFD entry: got nil error, want non-nil")
}
}
// benchmarkDecode benchmarks the decoding of an image.
func benchmarkDecode(b *testing.B, filename string) {
b.StopTimer()
contents, err := ioutil.ReadFile(testdataDir + filename)
if err != nil {
b.Fatal(err)
}
r := &buffer{buf: contents}
b.StartTimer()
for i := 0; i < b.N; i++ {
_, err := Decode(r)
if err != nil {
b.Fatal("Decode:", err)
}
}
}
func BenchmarkDecodeCompressed(b *testing.B) { benchmarkDecode(b, "video-001.tiff") }
func BenchmarkDecodeUncompressed(b *testing.B) { benchmarkDecode(b, "video-001-uncompressed.tiff") }