code review 13243047: go.image/tiff: encoder support Gray/Gray16 format

tiff/writer_test.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 = []struct {
         filename string
         opts     *Options
 }{
         {"video-001.tiff", nil},
-        //{"video-001-16bit.tiff", nil},
         {"video-001-gray.tiff", nil},
         {"video-001-gray-16bit.tiff", nil},
         {"video-001-paletted.tiff", nil},
         {"bw-packbits.tiff", nil},
         {"video-001.tiff", &Options{Predictor: true}},
         {"video-001.tiff", &Options{Compression: Deflate}},
         {"video-001.tiff", &Options{Predictor: true, Compression: Deflate}},
 }
 
 func openImage(filename string) (image.Image, error) {
@@ skipping 36 matching lines @@
         if err := Encode(out, m0, nil); 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.

[nigeltao, 2013/09/13 07:36:59]

I'd delete the obvious comment.

 func BenchmarkEncode(b *testing.B) {
-        img, err := openImage("video-001.tiff")
+        benchmarkEncode(b, "video-001.tiff", 4)
+}
+
+func BenchmarkEncodePaletted(b *testing.B) {
+        benchmarkEncode(b, "video-001-paletted.tiff", 1)
+}
+
+func BenchmarkEncodeGray(b *testing.B) {
+        benchmarkEncode(b, "video-001-gray.tiff", 1)
+}
+
+func BenchmarkEncodeGray16(b *testing.B) {
+        benchmarkEncode(b, "video-001-gray-16bit.tiff", 2)
+}
+
+func benchmarkEncode(b *testing.B, name string, pixelSize int) {
+        img, err := openImage(name)
         if err != nil {
                 b.Fatal(err)
         }
         s := img.Bounds().Size()
-        b.SetBytes(int64(s.X * s.Y * 4))
+        b.SetBytes(int64(s.X * s.Y * pixelSize))
         b.ResetTimer()
         for i := 0; i < b.N; i++ {
                 Encode(ioutil.Discard, img, nil)
         }
 }
-
-func BenchmarkEncodePaletted(b *testing.B) {
-        img, err := openImage("video-001-paletted.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, nil)
-        }
-}
-
-func BenchmarkEncodeGray(b *testing.B) {
-        img, err := openImage("video-001-gray.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, nil)
-        }
-}
-
-func BenchmarkEncodeGray16(b *testing.B) {
-        img, err := openImage("video-001-gray-16bit.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, nil)
-        }
-}