refactor(#47): minor refactors, code normalization and test coverage

README.md

@@ -238,7 +238,7 @@ bimg.Write("new.jpg", newImage)
 
 Run the process passing the `DEBUG` environment variable
 ```
-DEBUG=* ./app 
+DEBUG=bimg ./app 
 ```
 
 Enable libvips traces (note that a lot of data will be written in stdout):
@@ -248,6 +248,12 @@ VIPS_TRACE=1 ./app
 
 ### Programmatic API 
 
+#### func  ColourspaceIsSupported
+
+```go
+func ColourspaceIsSupported(buf []byte) (bool, error)
+```
+Check in the image colourspace is supported by libvips
 
 #### func  DetermineImageTypeName
 
@@ -295,7 +301,7 @@ func Resize(buf []byte, o Options) ([]byte, error)
 ```go
 func Shutdown()
 ```
-Thread-safe function to shutdown libvips. You could call this to drop caches as
+Thread-safe function to shutdown libvips. You can call this to drop caches as
 well. If libvips was already initialized, the function is no-op
 
 #### func  VipsDebugInfo
@@ -383,6 +389,20 @@ func NewImage(buf []byte) *Image
 ```
 Creates a new image
 
+#### func (*Image) Colourspace
+
+```go
+func (i *Image) Colourspace(c Interpretation) ([]byte, error)
+```
+Colour space conversion
+
+#### func (*Image) ColourspaceIsSupported
+
+```go
+func (i *Image) ColourspaceIsSupported() (bool, error)
+```
+Check if the current image has a valid colourspace
+
 #### func (*Image) Convert
 
 ```go
@@ -453,6 +473,14 @@ func (i *Image) Image() []byte
 ```
 Get image buffer
 
+#### func (*Image) Interpretation
+
+```go
+func (i *Image) Interpretation() (Interpretation, error)
+```
+Get the image interpretation type See:
+http://www.vips.ecs.soton.ac.uk/supported/current/doc/html/libvips/VipsImage.html#VipsInterpretation
+
 #### func (*Image) Metadata
 
 ```go
@@ -533,6 +561,7 @@ type ImageMetadata struct {
   Profile     bool
   Type        string
   Space       string
+  Colourspace string
   Size        ImageSize
 }
 ```
@@ -609,6 +638,37 @@ const (
 func (i Interpolator) String() string
 ```
 
+#### type Interpretation
+
+```go
+type Interpretation int
+```
+
+Image interpretation type See:
+http://www.vips.ecs.soton.ac.uk/supported/current/doc/html/libvips/VipsImage.html#VipsInterpretation
+
+```go
+const (
+  INTERPRETATION_ERROR     Interpretation = C.VIPS_INTERPRETATION_ERROR
+  INTERPRETATION_MULTIBAND Interpretation = C.VIPS_INTERPRETATION_MULTIBAND
+  INTERPRETATION_B_W       Interpretation = C.VIPS_INTERPRETATION_B_W
+  INTERPRETATION_CMYK      Interpretation = C.VIPS_INTERPRETATION_CMYK
+  INTERPRETATION_RGB       Interpretation = C.VIPS_INTERPRETATION_RGB
+  INTERPRETATION_sRGB      Interpretation = C.VIPS_INTERPRETATION_sRGB
+  INTERPRETATION_RGB16     Interpretation = C.VIPS_INTERPRETATION_RGB16
+  INTERPRETATION_GREY16    Interpretation = C.VIPS_INTERPRETATION_GREY16
+  INTERPRETATION_scRGB     Interpretation = C.VIPS_INTERPRETATION_scRGB
+)
+```
+
+#### func  ImageInterpretation
+
+```go
+func ImageInterpretation(buf []byte) (Interpretation, error)
+```
+Get the image interpretation type See:
+http://www.vips.ecs.soton.ac.uk/supported/current/doc/html/libvips/VipsImage.html#VipsInterpretation
+
 #### type Options
 
 ```go
@@ -636,6 +696,7 @@ type Options struct {
   Watermark      Watermark
   Type           ImageType
   Interpolator   Interpolator
+  Interpretation Interpretation
 }
 ```
 

image.go

@@ -155,6 +155,17 @@ func (i *Image) Metadata() (ImageMetadata, error) {
 	return Metadata(i.buffer)
 }
 
+// Get the image interpretation type
+// See: http://www.vips.ecs.soton.ac.uk/supported/current/doc/html/libvips/VipsImage.html#VipsInterpretation
+func (i *Image) Interpretation() (Interpretation, error) {
+	return ImageInterpretation(i.buffer)
+}
+
+// Check if the current image has a valid colourspace
+func (i *Image) ColourspaceIsSupported() (bool, error) {
+	return ColourspaceIsSupported(i.buffer)
+}
+
 // Get image type format (jpeg, png, webp, tiff)
 func (i *Image) Type() string {
 	return DetermineImageTypeName(i.buffer)

image_test.go

@@ -262,12 +262,36 @@ func TestImageMetadata(t *testing.T) {
 	}
 }
 
+func TestInterpretation(t *testing.T) {
+	interpretation, err := initImage("test.jpg").Interpretation()
+	if err != nil {
+		t.Errorf("Cannot process the image: %#v", err)
+	}
+	if interpretation != INTERPRETATION_sRGB {
+		t.Errorf("Invalid interpretation: %d", interpretation)
+	}
+}
+
 func TestImageColourspaceBW(t *testing.T) {
-	buf, err := initImage("test.jpg").Colourspace(B_W)
+	buf, err := initImage("test.jpg").Colourspace(INTERPRETATION_B_W)
+	if err != nil {
+		t.Errorf("Cannot process the image: %#v", err)
+	}
+
+	interpretation, err := ImageInterpretation(buf)
+	if interpretation != INTERPRETATION_B_W {
+		t.Errorf("Invalid colourspace")
+	}
+}
+
+func TestImageColourspaceIsSupported(t *testing.T) {
+	supported, err := initImage("test.jpg").ColourspaceIsSupported()
 	if err != nil {
 		t.Errorf("Cannot process the image: %#v", err)
 	}
-	Write("fixtures/test_image_colourspace_b_w.jpg", buf)
+	if supported != true {
+		t.Errorf("Non-supported colourspace")
+	}
 }
 
 func TestFluentInterface(t *testing.T) {

metadata.go

@@ -18,6 +18,7 @@ type ImageMetadata struct {
 	Profile     bool
 	Type        string
 	Space       string
+	Colourspace string
 	Size        ImageSize
 }
 
@@ -34,6 +35,17 @@ func Size(buf []byte) (ImageSize, error) {
 	}, nil
 }
 
+// Check in the image colourspace is supported by libvips
+func ColourspaceIsSupported(buf []byte) (bool, error) {
+	return vipsColourspaceIsSupportedBuffer(buf)
+}
+
+// Get the image interpretation type
+// See: http://www.vips.ecs.soton.ac.uk/supported/current/doc/html/libvips/VipsImage.html#VipsInterpretation
+func ImageInterpretation(buf []byte) (Interpretation, error) {
+	return vipsInterpretationBuffer(buf)
+}
+
 // Extract the image metadata (size, type, alpha channel, profile, EXIF orientation...)
 func Metadata(buf []byte) (ImageMetadata, error) {
 	defer C.vips_thread_shutdown()

metadata_test.go

@@ -38,9 +38,9 @@ func TestMetadata(t *testing.T) {
 		profile     bool
 		space       string
 	}{
-		{"test.jpg", "jpeg", 0, false, false, "bicubic"},
+		{"test.jpg", "jpeg", 0, false, false, "srgb"},
-		{"test.png", "png", 0, true, false, "bicubic"},
+		{"test.png", "png", 0, true, false, "srgb"},
-		{"test.webp", "webp", 0, false, false, "bicubic"},
+		{"test.webp", "webp", 0, false, false, "srgb"},
 	}
 
 	for _, file := range files {
@@ -61,6 +61,58 @@ func TestMetadata(t *testing.T) {
 		if metadata.Profile != file.profile {
 			t.Fatalf("Unexpected image profile: %s != %s", metadata.Profile, file.profile)
 		}
+		if metadata.Space != file.space {
+			t.Fatalf("Unexpected image profile: %s != %s", metadata.Profile, file.profile)
+		}
+	}
+}
+
+func TestImageInterpretation(t *testing.T) {
+	files := []struct {
+		name           string
+		interpretation Interpretation
+	}{
+		{"test.jpg", INTERPRETATION_sRGB},
+		{"test.png", INTERPRETATION_sRGB},
+		{"test.webp", INTERPRETATION_sRGB},
+	}
+
+	for _, file := range files {
+		interpretation, err := ImageInterpretation(readFile(file.name))
+		if err != nil {
+			t.Fatalf("Cannot read the image: %s -> %s", file.name, err)
+		}
+		if interpretation != file.interpretation {
+			t.Fatalf("Unexpected image interpretation")
+		}
+	}
+}
+
+func TestColourspaceIsSupported(t *testing.T) {
+	files := []struct {
+		name string
+	}{
+		{"test.jpg"},
+		{"test.png"},
+		{"test.webp"},
+	}
+
+	for _, file := range files {
+		supported, err := ColourspaceIsSupported(readFile(file.name))
+		if err != nil {
+			t.Fatalf("Cannot read the image: %s -> %s", file.name, err)
+		}
+		if supported != true {
+			t.Fatalf("Unsupported image colourspace")
+		}
+	}
+
+	supported, err := initImage("test.jpg").ColourspaceIsSupported()
+	if err != nil {
+		t.Errorf("Cannot process the image: %#v", err)
+	}
+	if supported != true {
+		t.Errorf("Non-supported colourspace")
 	}
 }
 

options.go

@@ -55,18 +55,20 @@ const (
 	VERTICAL   Direction = C.VIPS_DIRECTION_VERTICAL
 )
 
+// Image interpretation type
+// See: http://www.vips.ecs.soton.ac.uk/supported/current/doc/html/libvips/VipsImage.html#VipsInterpretation
 type Interpretation int
 
 const (
-	ERROR Interpretation = C.VIPS_INTERPRETATION_ERROR
+	INTERPRETATION_ERROR     Interpretation = C.VIPS_INTERPRETATION_ERROR
-	MULTIBAND Interpretation = C.VIPS_INTERPRETATION_MULTIBAND
+	INTERPRETATION_MULTIBAND Interpretation = C.VIPS_INTERPRETATION_MULTIBAND
-	B_W Interpretation = C.VIPS_INTERPRETATION_B_W
+	INTERPRETATION_B_W       Interpretation = C.VIPS_INTERPRETATION_B_W
-	CMYK Interpretation = C.VIPS_INTERPRETATION_CMYK
+	INTERPRETATION_CMYK      Interpretation = C.VIPS_INTERPRETATION_CMYK
-	RGB Interpretation = C.VIPS_INTERPRETATION_RGB
+	INTERPRETATION_RGB       Interpretation = C.VIPS_INTERPRETATION_RGB
-	sRGB Interpretation = C.VIPS_INTERPRETATION_sRGB
+	INTERPRETATION_sRGB      Interpretation = C.VIPS_INTERPRETATION_sRGB
-	RGB16 Interpretation = C.VIPS_INTERPRETATION_RGB16
+	INTERPRETATION_RGB16     Interpretation = C.VIPS_INTERPRETATION_RGB16
-	GREY16 Interpretation = C.VIPS_INTERPRETATION_GREY16
+	INTERPRETATION_GREY16    Interpretation = C.VIPS_INTERPRETATION_GREY16
-	scRGB Interpretation = C.VIPS_INTERPRETATION_scRGB
+	INTERPRETATION_scRGB     Interpretation = C.VIPS_INTERPRETATION_scRGB
 )
 
 const WATERMARK_FONT = "sans 10"

resize.go

@@ -125,7 +125,7 @@ func Resize(buf []byte, o Options) ([]byte, error) {
 		Interpretation: o.Interpretation,
 	}
 
-	// Finally save as buffer
+	// Finally get the resultant buffer
 	buf, err = vipsSave(image, saveOptions)
 	if err != nil {
 		return nil, err
@@ -145,7 +145,7 @@ func applyDefaults(o *Options, imageType ImageType) {
 		o.Type = imageType
 	}
 	if o.Interpretation == 0 {
-		o.Interpretation = sRGB
+		o.Interpretation = INTERPRETATION_sRGB
 	}
 }
 

vips.go

@@ -224,41 +224,85 @@ func vipsRead(buf []byte) (*C.struct__VipsImage, ImageType, error) {
 	return image, imageType, nil
 }
 
-func vipsSave(image *C.struct__VipsImage, o vipsSaveOptions) ([]byte, error) {
+func vipsColourspaceIsSupportedBuffer(buf []byte) (bool, error) {
-	length := C.size_t(0)
+	image, _, err := vipsRead(buf)
-	err := C.int(0)
+	defer C.g_object_unref(C.gpointer(image))
-	interlace := C.int(boolToInt(o.Interlace))
+	if err != nil {
-	if o.Interpretation == 0 {
+		return false, err
-		o.Interpretation = sRGB
+	}
+	return vipsColourspaceIsSupported(image), nil
+}
+
+func vipsColourspaceIsSupported(image *C.struct__VipsImage) bool {
+	return int(C.vips_colourspace_issupported_bridge(image)) == 1
 }
-	interpretation := C.VipsInterpretation(o.Interpretation)
 
+func vipsInterpretationBuffer(buf []byte) (Interpretation, error) {
+	image, _, err := vipsRead(buf)
+	defer C.g_object_unref(C.gpointer(image))
+	if err != nil {
+		return Interpretation(-1), err
+	}
+	return vipsInterpretation(image), nil
+}
+
+func vipsInterpretation(image *C.struct__VipsImage) Interpretation {
+	return Interpretation(C.vips_image_guess_interpretation_bridge(image))
+}
+
+func vipsPreSave(image *C.struct__VipsImage, o *vipsSaveOptions) (*C.struct__VipsImage, error) {
 	// Remove ICC profile metadata
 	if o.NoProfile {
 		C.remove_profile(image)
 	}
 
-	// Force RGB color space
+	// Use a default interpretation and cast it to C type
+	if o.Interpretation == 0 {
+		o.Interpretation = INTERPRETATION_sRGB
+	}
+	interpretation := C.VipsInterpretation(o.Interpretation)
+
+	// Apply the proper colour space
 	var outImage *C.struct__VipsImage
-	C.vips_colourspace_bridge(image, &outImage, interpretation)
+	if vipsColourspaceIsSupported(image) {
+		err := int(C.vips_colourspace_bridge(image, &outImage, interpretation))
+		C.g_object_unref(C.gpointer(image))
+		if err != 0 {
+			return nil, catchVipsError()
+		}
+		image = outImage
+	}
 
+	return image, nil
+}
+
+func vipsSave(image *C.struct__VipsImage, o vipsSaveOptions) ([]byte, error) {
 	defer C.g_object_unref(C.gpointer(image))
-	defer C.g_object_unref(C.gpointer(outImage))
+
+	image, err := vipsPreSave(image, &o)
+	if err != nil {
+		return nil, err
+	}
+
+	length := C.size_t(0)
+	saveErr := C.int(0)
+	interlace := C.int(boolToInt(o.Interlace))
+	quality := C.int(o.Quality)
 
 	var ptr unsafe.Pointer
 	switch o.Type {
-	case PNG:
-		err = C.vips_pngsave_bridge(outImage, &ptr, &length, 1, C.int(o.Compression), C.int(o.Quality), interlace)
-		break
 	case WEBP:
-		err = C.vips_webpsave_bridge(outImage, &ptr, &length, 1, C.int(o.Quality))
+		saveErr = C.vips_webpsave_bridge(image, &ptr, &length, 1, quality)
+		break
+	case PNG:
+		saveErr = C.vips_pngsave_bridge(image, &ptr, &length, 1, C.int(o.Compression), quality, interlace)
 		break
 	default:
-		err = C.vips_jpegsave_bridge(outImage, &ptr, &length, 1, C.int(o.Quality), interlace)
+		saveErr = C.vips_jpegsave_bridge(image, &ptr, &length, 1, quality, interlace)
 		break
 	}
 
-	if int(err) != 0 {
+	if int(saveErr) != 0 {
 		return nil, catchVipsError()
 	}
 

vips.h

@@ -134,6 +134,17 @@ vips_extract_area_bridge(VipsImage *in, VipsImage **out, int left, int top, int
 	return vips_extract_area(in, out, left, top, width, height, NULL);
 };
 
+int
+vips_colourspace_issupported_bridge(VipsImage *in)
+{
+	return vips_colourspace_issupported(in) ? 1 : 0;
+};
+
+VipsInterpretation
+vips_image_guess_interpretation_bridge(VipsImage *in) {
+	return vips_image_guess_interpretation(in);
+};
+
 int
 vips_colourspace_bridge(VipsImage *in, VipsImage **out, VipsInterpretation space)
 {