golang-image/tiff/writer_test.go
Benny Siegert c35a1ecb6c go.image/tiff: use optimized routines for RGBA and NRGBA
Performance for an RGBA image:

benchmark          old ns/op    new ns/op    delta
BenchmarkEncode      1633495         7897  -99.52%

benchmark           old MB/s     new MB/s  speedup
BenchmarkEncode        37.83      7824.96  206.85x

NRGBA images are now encoded as such, the spec calls it
"unassociated alpha".

R=nigeltao, rsc
CC=golang-dev
https://golang.org/cl/6308049
2012-06-13 10:40:38 +10:00

80 lines
1.5 KiB
Go

// Copyright 2012 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"
"image"
"io/ioutil"
"os"
"testing"
)
var roundtripTests = []string{
"video-001.tiff",
"bw-packbits.tiff",
}
func openImage(filename string) (image.Image, error) {
f, err := os.Open(testdataDir + filename)
if err != nil {
return nil, err
}
defer f.Close()
return Decode(f)
}
func TestRoundtrip(t *testing.T) {
for _, filename := range roundtripTests {
img, err := openImage(filename)
if err != nil {
t.Fatal(err)
}
out := new(bytes.Buffer)
err = Encode(out, img)
if err != nil {
t.Fatal(err)
}
img2, err := Decode(&buffer{buf: out.Bytes()})
if err != nil {
t.Fatal(err)
}
compare(t, img, img2)
}
}
// TestRoundtrip2 tests that encoding and decoding an image whose
// origin is not (0, 0) gives the same thing.
func TestRoundtrip2(t *testing.T) {
m0 := image.NewRGBA(image.Rect(3, 4, 9, 8))
for i := range m0.Pix {
m0.Pix[i] = byte(i)
}
out := new(bytes.Buffer)
if err := Encode(out, m0); err != nil {
t.Fatal(err)
}
m1, err := Decode(&buffer{buf: out.Bytes()})
if err != nil {
t.Fatal(err)
}
compare(t, m0, m1)
}
// BenchmarkEncode benchmarks the encoding of an image.
func BenchmarkEncode(b *testing.B) {
img, err := openImage("video-001.tiff")
if err != nil {
b.Fatal(err)
}
s := img.Bounds().Size()
b.SetBytes(int64(s.X * s.Y * 4))
b.ResetTimer()
for i := 0; i < b.N; i++ {
Encode(ioutil.Discard, img)
}
}