golang-image/tiff/reader_test.go
Nigel Tao 996c335c4a go.image/{bmp,tiff}: move tiff/testdata to testdata.
Add a "compare to golden PNG" test for BMP and TIFF.

R=rsc
CC=golang-dev
https://golang.org/cl/5601054
2012-01-31 14:02:27 +11:00

154 lines
3.6 KiB
Go

// 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 (
"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")
}
// TestNoRPS tries to decode 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) {
f, err := os.Open(testdataDir + "no_rps.tiff")
if err != nil {
t.Fatal(err)
}
defer f.Close()
_, err = Decode(f)
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 compare(t *testing.T, img0, img1 image.Image) {
b := img1.Bounds()
if !b.Eq(img0.Bounds()) {
t.Fatalf("wrong image size: want %s, got %s", img0.Bounds(), b)
}
for y := b.Min.Y; y < b.Max.Y; y++ {
for x := b.Min.X; x < b.Max.X; x++ {
c0 := img0.At(x, y)
c1 := img1.At(x, y)
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) {
f0, err := os.Open(testdataDir + "video-001.png")
if err != nil {
t.Fatal(err)
}
defer f0.Close()
img0, _, err := image.Decode(f0)
if err != nil {
t.Fatal(err)
}
f1, err := os.Open(testdataDir + "video-001.tiff")
if err != nil {
t.Fatal(err)
}
defer f1.Close()
img1, _, err := image.Decode(f1)
if err != nil {
t.Fatal(err)
}
compare(t, img0, img1)
}
// 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 {
f, err := os.Open(testdataDir + name)
if err != nil {
t.Fatal(err)
}
defer f.Close()
if img0 == nil {
img0, err = Decode(f)
if err != nil {
t.Fatalf("decoding %s: %v", name, err)
}
continue
}
img1, err := Decode(f)
if err != nil {
t.Fatalf("decoding %s: %v", name, err)
}
compare(t, img0, img1)
}
}
// 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 {
panic(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") }