add more exif data to metadata

metadata.go

@@ -22,6 +22,15 @@ type ImageMetadata struct {
 	Space       string
 	Colourspace string
 	Size        ImageSize
+	EXIF EXIF
+}
+
+type EXIF struct {
+	Make string
+	Model string
+	Orientation int
+	Software string
+	Datetime string
 }
 
 // Size returns the image size by width and height pixels.
@@ -63,14 +72,23 @@ func Metadata(buf []byte) (ImageMetadata, error) {
 		Height: int(image.Ysize),
 	}
 
+	orientation := vipsExifOrientation(image)
+
 	metadata := ImageMetadata{
 		Size:        size,
 		Channels:    int(image.Bands),
-		Orientation: vipsExifOrientation(image),
+		Orientation: orientation,
 		Alpha:       vipsHasAlpha(image),
 		Profile:     vipsHasProfile(image),
 		Space:       vipsSpace(image),
 		Type:        ImageTypeName(imageType),
+		EXIF: EXIF{
+			Make: vipsExifMake(image),
+			Model: vipsExifModel(image),
+			Orientation: orientation,
+			Software: vipsExifSoftware(image),
+			Datetime: vipsExifDatetime(image),
+		},
 	}
 
 	return metadata, nil

metadata_test.go

@@ -89,6 +89,44 @@ func TestImageInterpretation(t *testing.T) {
 	}
 }
 
+func TestEXIF(t *testing.T) {
+	files := []struct {
+		name           string
+		make string
+		model string
+		orientation int
+		software string
+		datetime string
+	}{
+		{"test.jpg", "", "", 0, "", ""},
+		{"exif/Landscape_1.jpg", "", "", 1, "", ""},
+		{"test_exif.jpg", "Jolla", "Jolla", 1, "", "2014:09:21 16:00:56"},
+		{"test_exif_canon.jpg", "Canon", "Canon EOS 40D", 1, "GIMP 2.4.5", "2008:07:31 10:38:11"},
+	}
+
+	for _, file := range files {
+		metadata, err := Metadata(readFile(file.name))
+		if err != nil {
+			t.Fatalf("Cannot read the image: %s -> %s", file.name, err)
+		}
+		if metadata.EXIF.Make != file.make {
+			t.Fatalf("Unexpected image exif make: %s != %s", metadata.EXIF.Make, file.make)
+		}
+		if metadata.EXIF.Model != file.model {
+			t.Fatalf("Unexpected image exif model: %s != %s", metadata.EXIF.Model, file.model)
+		}
+		if metadata.EXIF.Orientation != file.orientation {
+			t.Fatalf("Unexpected image exif orientation: %d != %d", metadata.EXIF.Orientation, file.orientation)
+		}
+		if metadata.EXIF.Software != file.software {
+			t.Fatalf("Unexpected image exif software: %s != %s", metadata.EXIF.Software, file.software)
+		}
+		if metadata.EXIF.Datetime != file.datetime {
+			t.Fatalf("Unexpected image exif datetime: %s != %s", metadata.EXIF.Datetime, file.datetime)
+		}
+	}
+}
+
 func TestColourspaceIsSupported(t *testing.T) {
 	files := []struct {
 		name string

vips.go

@@ -215,10 +215,33 @@ func VipsIsTypeSupportedSave(t ImageType) bool {
 	return false
 }
 
+func vipsExifMake(image *C.VipsImage) string {
+	return vipsExifShort(C.GoString(C.vips_exif_make(image)))
+}
+
+func vipsExifModel(image *C.VipsImage) string {
+	return vipsExifShort(C.GoString(C.vips_exif_model(image)))
+}
+
 func vipsExifOrientation(image *C.VipsImage) int {
 	return int(C.vips_exif_orientation(image))
 }
 
+func vipsExifSoftware(image *C.VipsImage) string {
+	return vipsExifShort(C.GoString(C.vips_exif_software(image)))
+}
+
+func vipsExifDatetime(image *C.VipsImage) string {
+	return vipsExifShort(C.GoString(C.vips_exif_datetime(image)))
+}
+
+func vipsExifShort(s string) string {
+	if strings.Contains(s, " (") {
+		return s[:strings.Index(s, "(")-1]
+	}
+	return s
+}
+
 func vipsHasAlpha(image *C.VipsImage) bool {
 	return int(C.has_alpha_channel(image)) > 0
 }

vips.h

@@ -18,7 +18,11 @@
 #define VIPS_ANGLE_D270 VIPS_ANGLE_270
 #endif
 
+#define EXIF_IFD0_MAKE "exif-ifd0-Make"
+#define EXIF_IFD0_MODEL "exif-ifd0-Model"
 #define EXIF_IFD0_ORIENTATION "exif-ifd0-Orientation"
+#define EXIF_IFD0_SOFTWARE "exif-ifd0-Software"
+#define EXIF_IFD0_DATETIME "exif-ifd0-DateTime"
 
 #define INT_TO_GBOOLEAN(bool) (bool > 0 ? TRUE : FALSE)
 
@@ -218,19 +222,48 @@ vips_rotate_bridge(VipsImage *in, VipsImage **out, int angle) {
 	}
 }
 
+const char *
+vips_exif_tag(VipsImage *image, const char *tag) {
+	const char *exif;
+	if (
+		vips_image_get_typeof(image, tag) != 0 &&
+		!vips_image_get_string(image, tag, &exif)
+	) {
+		return &exif[0];
+	}
+	return "";
+}
+
+const char *
+vips_exif_make(VipsImage *image) {
+	return vips_exif_tag(image, EXIF_IFD0_MAKE);
+}
+
+const char *
+vips_exif_model(VipsImage *image) {
+	return vips_exif_tag(image, EXIF_IFD0_MODEL);
+}
+
 int
 vips_exif_orientation(VipsImage *image) {
 	int orientation = 0;
-	const char *exif;
+	const char *exif = vips_exif_tag(image, EXIF_IFD0_ORIENTATION);
-	if (
+	if (strcmp(exif, "")) {
-		vips_image_get_typeof(image, EXIF_IFD0_ORIENTATION) != 0 &&
-		!vips_image_get_string(image, EXIF_IFD0_ORIENTATION, &exif)
-	) {
 		orientation = atoi(&exif[0]);
 	}
 	return orientation;
 }
 
+const char *
+vips_exif_software(VipsImage *image) {
+	return vips_exif_tag(image, EXIF_IFD0_SOFTWARE);
+}
+
+const char *
+vips_exif_datetime(VipsImage *image) {
+	return vips_exif_tag(image, EXIF_IFD0_DATETIME);
+}
+
 int
 interpolator_window_size(char const *name) {
 	VipsInterpolate *interpolator = vips_interpolate_new(name);