golang-image/tiff/reader_test.go
Nigel Tao cc3e6234e7 go.image: initial code.
Manual edits to README.
Moved from main Go repository, deleted Makefiles.

Tested with go test code.google.com/p/go.image/...

Fixes golang/go#2797.

R=rsc, rsc, r
CC=golang-dev
https://golang.org/cl/5593053
2012-01-31 11:32:50 +11:00

120 lines
2.8 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"
)
// 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("testdata/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)
}
}
}
// 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("testdata/" + 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)
}
b := img1.Bounds()
// Compare images.
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)
}
}
}
}
}
const filename = "testdata/video-001-uncompressed.tiff"
// BenchmarkDecode benchmarks the decoding of an image.
func BenchmarkDecode(b *testing.B) {
b.StopTimer()
contents, err := ioutil.ReadFile(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)
}
}
}