Add image.Exif

Note that we will probably need to add some metadata cache for this to scale.

Fixes #4600

go.mod

@@ -41,6 +41,7 @@ require (
  github.com/pkg/errors v0.8.1
  github.com/rogpeppe/go-internal v1.3.0
  github.com/russross/blackfriday v1.5.3-0.20190124082335-a477dd164691
+ github.com/rwcarlsen/goexif v0.0.0-20190401172101-9e8deecbddbd
  github.com/sanity-io/litter v1.1.0
  github.com/spf13/afero v1.2.2
  github.com/spf13/cast v1.3.0

go.sum

@@ -263,6 +263,8 @@ github.com/russross/blackfriday v1.5.2 h1:HyvC0ARfnZBqnXwABFeSZHpKvJHJJfPz81GNue
 github.com/russross/blackfriday v1.5.2/go.mod h1:JO/DiYxRf+HjHt06OyowR9PTA263kcR/rfWxYHBV53g=
 github.com/russross/blackfriday v1.5.3-0.20190124082335-a477dd164691 h1:auJkuUc4uOuZNoH9jGLvqVaDLiuCOh/LY+Qw5NBFo4I=
 github.com/russross/blackfriday v1.5.3-0.20190124082335-a477dd164691/go.mod h1:JO/DiYxRf+HjHt06OyowR9PTA263kcR/rfWxYHBV53g=
+github.com/rwcarlsen/goexif v0.0.0-20190401172101-9e8deecbddbd h1:CmH9+J6ZSsIjUK3dcGsnCnO41eRBOnY12zwkn5qVwgc=
+github.com/rwcarlsen/goexif v0.0.0-20190401172101-9e8deecbddbd/go.mod h1:hPqNNc0+uJM6H+SuU8sEs5K5IQeKccPqeSjfgcKGgPk=
 github.com/sanity-io/litter v1.1.0 h1:BllcKWa3VbZmOZbDCoszYLk7zCsKHz5Beossi8SUcTc=
 github.com/sanity-io/litter v1.1.0/go.mod h1:CJ0VCw2q4qKU7LaQr3n7UOSHzgEMgcGco7N/SkZQPjw=
 github.com/sergi/go-diff v1.0.0 h1:Kpca3qRNrduNnOQeazBd0ysaKrUJiIuISHxogkT9RPQ=

resources/image.go

@@ -21,6 +21,9 @@ import (
  _ "image/png"
  "os"
  "strings"
+ "sync"
+
+ "github.com/gohugoio/hugo/resources/images/exif"
 
  "github.com/gohugoio/hugo/resources/internal"
 
@@ -48,12 +51,56 @@ var (
 type imageResource struct {
  *images.Image
 
+ // When a image is processed in a chain, this holds the reference to the
+ // original (first).
+ root *imageResource
+
+ exifInit sync.Once
+ exifInitErr error
+ exif *exif.Exif
+
  baseResource
 }
 
+// ImageData contains image related data, typically Exif.
+type ImageData map[string]interface{}
+
+func (i *imageResource) Exif() (*exif.Exif, error) {
+ return i.root.getExif()
+}
+
+func (i *imageResource) getExif() (*exif.Exif, error) {
+
+ i.exifInit.Do(func() {
+ supportsExif := i.Format == images.JPEG || i.Format == images.TIFF
+ if !supportsExif {
+ return
+ }
+
+ f, err := i.root.ReadSeekCloser()
+ if err != nil {
+ i.exifInitErr = err
+ return
+ }
+ defer f.Close()
+
+ x, err := i.getSpec().imaging.DecodeExif(f)
+ if err != nil {
+ i.exifInitErr = err
+ return
+ }
+
+ i.exif = x
+
+ })
+
+ return i.exif, i.exifInitErr
+}
+
 func (i *imageResource) Clone() resource.Resource {
  gr := i.baseResource.Clone().(baseResource)
  return &imageResource{
+ root: i.root,
  Image: i.WithSpec(gr),
  baseResource: gr,
  }
@@ -74,6 +121,7 @@ func (i *imageResource) cloneWithUpdates(u *transformationUpdate) (baseResource,
  }
 
  return &imageResource{
+ root: i.root,
  Image: img,
  baseResource: base,
  }, nil
@@ -217,6 +265,7 @@ func (i *imageResource) clone(img image.Image) *imageResource {
 
  return &imageResource{
  Image: image,
+ root: i.root,
  baseResource: spec,
  }
 }

resources/image_test.go

@@ -332,6 +332,32 @@ func TestSVGImageContent(t *testing.T) {
  c.Assert(content.(string), qt.Contains, `<svg height="100" width="100">`)
 }
 
+func TestImageExif(t *testing.T) {
+ c := qt.New(t)
+ image := fetchImage(c, "sunset.jpg")
+
+ x, err := image.Exif()
+ c.Assert(err, qt.IsNil)
+ c.Assert(x, qt.Not(qt.IsNil))
+
+ c.Assert(x.Date.Format("2006-01-02"), qt.Equals, "2017-10-27")
+
+ // Malaga: https://goo.gl/taazZy
+ c.Assert(x.Lat, qt.Equals, float64(36.59744166666667))
+ c.Assert(x.Long, qt.Equals, float64(-4.50846))
+
+ v, found := x.Values["LensModel"]
+ c.Assert(found, qt.Equals, true)
+ lensModel, ok := v.(string)
+ c.Assert(ok, qt.Equals, true)
+ c.Assert(lensModel, qt.Equals, "smc PENTAX-DA* 16-50mm F2.8 ED AL [IF] SDM")
+
+ resized, _ := image.Resize("300x200")
+ x2, _ := resized.Exif()
+ c.Assert(x2, qt.Equals, x)
+
+}
+
 func TestImageOperationsGolden(t *testing.T) {
  c := qt.New(t)
  c.Parallel()

resources/images/config.go

@@ -119,6 +119,11 @@ func DecodeConfig(m map[string]interface{}) (Imaging, error) {
  i.ResampleFilter = filter
  }
 
+ if strings.TrimSpace(i.Exif.IncludeFields) == "" && strings.TrimSpace(i.Exif.ExcludeFields) == "" {
+ // Don't change this for no good reason. Please don't.
+ i.Exif.ExcludeFields = "GPS|Exif|Exposure[M|P|B]|Contrast|Resolution|Sharp|JPEG|Metering|Sensing|Saturation|ColorSpace|Flash|WhiteBalance"
+ }
+
  return i, nil
 }
 
@@ -279,4 +284,29 @@ type Imaging struct {
 
  // The anchor to use in Fill. Default is "smart", i.e. Smart Crop.
  Anchor string
+
+ Exif ExifConfig
+}
+
+type ExifConfig struct {
+
+ // Regexp matching the Exif fields you want from the (massive) set of Exif info
+ // available. As we cache this info to disk, this is for performance and
+ // disk space reasons more than anything.
+ // If you want it all, put ".*" in this config setting.
+ // Note that if neither this or ExcludeFields is set, Hugo will return a small
+ // default set.
+ IncludeFields string
+
+ // Regexp matching the Exif fields you want to exclude. This may be easier to use
+ // than IncludeFields above, depending on what you want.
+ ExcludeFields string
+
+ // Hugo extracts the "photo taken" date/time into .Date by default.
+ // Set this to true to turn it off.
+ DisableDate bool
+
+ // Hugo extracts the "photo taken where" (GPS latitude and longitude) into
+ // .Long and .Lat. Set this to true to turn it off.
+ DisableLatLong bool
 }

resources/images/config_test.go

@@ -64,6 +64,16 @@ func TestDecodeConfig(t *testing.T) {
  })
  c.Assert(err, qt.IsNil)
  c.Assert(imaging.Anchor, qt.Equals, "smart")
+
+ imaging, err = DecodeConfig(map[string]interface{}{
+ "exif": map[string]interface{}{
+ "disableLatLong": true,
+ },
+ })
+ c.Assert(err, qt.IsNil)
+ c.Assert(imaging.Exif.DisableLatLong, qt.Equals, true)
+ c.Assert(imaging.Exif.ExcludeFields, qt.Equals, "GPS|Exif|Exposure[M|P|B]|Contrast|Resolution|Sharp|JPEG|Metering|Sensing|Saturation|ColorSpace|Flash|WhiteBalance")
+
 }
 
 func TestDecodeImageConfig(t *testing.T) {