1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
|
package median_test
import (
"fmt"
"image"
"image/png"
"os"
"path/filepath"
"runtime"
"testing"
"github.com/soniakeys/quant"
"github.com/soniakeys/quant/median"
)
// TestMedian tests the median quantizer on png files found in the source
// directory. Output files are prefixed with _median_. Files beginning with
// _ are skipped when scanning for input files. Note nothing is tested
// with a fresh source tree--drop a png or two in the source directory
// before testing to give the test something to work on. Png files in the
// parent directory are similarly used for testing. Put files there
// to compare results of the different quantizers.
func TestMedian(t *testing.T) {
for _, p := range glob(t) {
f, err := os.Open(p)
if err != nil {
t.Log(err) // skip files that can't be opened
continue
}
img, err := png.Decode(f)
f.Close()
if err != nil {
t.Log(err) // skip files that can't be decoded
continue
}
pDir, pFile := filepath.Split(p)
for _, n := range []int{16, 256} {
// prefix _ on file name marks this as a result
fq, err := os.Create(fmt.Sprintf("%s_median_%d_%s", pDir, n, pFile))
if err != nil {
t.Fatal(err) // probably can't create any others
}
var q quant.Quantizer = median.Quantizer(n)
if err = png.Encode(fq, q.Paletted(img)); err != nil {
t.Fatal(err) // any problem is probably a problem for all
}
}
}
}
func glob(tb testing.TB) []string {
_, file, _, _ := runtime.Caller(0)
srcDir, _ := filepath.Split(file)
// ignore file names starting with _, those are result files.
imgs, err := filepath.Glob(srcDir + "[^_]*.png")
if err != nil {
tb.Fatal(err)
}
if srcDir > "" {
parentDir, _ := filepath.Split(srcDir[:len(srcDir)-1])
parentImgs, err := filepath.Glob(parentDir + "[^_]*.png")
if err != nil {
tb.Fatal(err)
}
imgs = append(parentImgs, imgs...)
}
return imgs
}
func BenchmarkPalette(b *testing.B) {
var img image.Image
for _, p := range glob(b) {
f, err := os.Open(p)
if err != nil {
b.Log(err) // skip files that can't be opened
continue
}
img, err = png.Decode(f)
f.Close()
if err != nil {
b.Log(err) // skip files that can't be decoded
continue
}
break
}
var q quant.Quantizer = median.Quantizer(256)
b.ResetTimer()
for i := 0; i < b.N; i++ {
q.Palette(img)
}
}
|
