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-rw-r--r--preproc/sauvola_test.go62
1 files changed, 62 insertions, 0 deletions
diff --git a/preproc/sauvola_test.go b/preproc/sauvola_test.go
new file mode 100644
index 0000000..1397a4f
--- /dev/null
+++ b/preproc/sauvola_test.go
@@ -0,0 +1,62 @@
+package preproc
+
+import (
+ "fmt"
+ "image"
+ "image/png"
+ "os"
+ "testing"
+)
+
+func TestBinarization(t *testing.T) {
+ cases := []struct {
+ name string
+ orig string
+ golden string
+ ksize float64
+ wsize int
+ }{
+ {"integralsauvola", "testdata/pg1.png", "testdata/pg1_integralsauvola_k0.5_w41.png", 0.5, 41},
+ {"integralsauvola", "testdata/pg1.png", "testdata/pg1_integralsauvola_k0.5_w19.png", 0.5, 19},
+ {"integralsauvola", "testdata/pg1.png", "testdata/pg1_integralsauvola_k0.3_w19.png", 0.3, 19},
+ {"sauvola", "testdata/pg1.png", "testdata/pg1_sauvola_k0.5_w41.png", 0.5, 41},
+ {"sauvola", "testdata/pg1.png", "testdata/pg1_sauvola_k0.5_w19.png", 0.5, 19},
+ {"sauvola", "testdata/pg1.png", "testdata/pg1_sauvola_k0.3_w19.png", 0.3, 19},
+ }
+
+ for _, c := range cases {
+ t.Run(fmt.Sprintf("%s_%0.1f_%d", c.name, c.ksize, c.wsize), func(t *testing.T) {
+ var actual *image.Gray
+ orig, err := decode(c.orig)
+ if err != nil {
+ t.Fatalf("Could not open file %s: %v\n", c.orig, err)
+ }
+ switch c.name {
+ case "integralsauvola":
+ actual = IntegralSauvola(orig, c.ksize, c.wsize)
+ case "sauvola":
+ actual = Sauvola(orig, c.ksize, c.wsize)
+ default:
+ t.Fatalf("No method %s\n", c.name)
+ }
+ if *update {
+ f, err := os.Create(c.golden)
+ defer f.Close()
+ if err != nil {
+ t.Fatalf("Could not open file %s to update: %v\n", c.golden, err)
+ }
+ err = png.Encode(f, actual)
+ if err != nil {
+ t.Fatalf("Could not encode update of %s: %v\n", c.golden, err)
+ }
+ }
+ golden, err := decode(c.golden)
+ if err != nil {
+ t.Fatalf("Could not open file %s: %v\n", c.golden, err)
+ }
+ if ! imgsequal(golden, actual) {
+ t.Errorf("Binarized %s differs to %s\n", c.orig, c.golden)
+ }
+ })
+ }
+}