webp-near-lossless (#31)

* Remember target profile in OptimizeICCProfile, set that profile later when saving webp.

* Move ICC optimization logic from C to go, save optimized profile as go variable

* Add golden file

* Add "near_lossless" parameter for saving webp

.gitignore

@@ -3,3 +3,4 @@ build/
 *.failed.*
 .vscode
 .idea
+/vips/vips.test

vips/color.c

@@ -2,6 +2,9 @@
 #include "icc_profiles.h"
 #include <unistd.h>
 
+#define SRGB_PROFILE_PATH SRGB_V2_MICRO_ICC_PATH
+#define GRAY_PROFILE_PATH SGRAY_V2_MICRO_ICC_PATH
+
 int is_colorspace_supported(VipsImage *in) {
 	return vips_colourspace_issupported(in) ? 1 : 0;
 }
@@ -11,29 +14,13 @@ int to_colorspace(VipsImage *in, VipsImage **out, VipsInterpretation space) {
 }
 
 // https://libvips.github.io/libvips/API/8.6/libvips-colour.html#vips-icc-transform
-int optimize_icc_profile(VipsImage *in, VipsImage **out, int isCmyk) {
-	// todo: check current embedded profile, and skip if already set
-
-    char *srgb_profile_path = SRGB_V2_MICRO_ICC_PATH;
-    char *gray_profile_path = SGRAY_V2_MICRO_ICC_PATH;
-
-    int channels = vips_image_get_bands(in);
-	int result;
-
-    if (channels > 2) {
-    	if (isCmyk == 1) {
-    		result = vips_icc_transform(in, out, srgb_profile_path, "input_profile", "cmyk", "intent", VIPS_INTENT_PERCEPTUAL, NULL);
-    	} else {
-        	result = vips_icc_transform(in, out, srgb_profile_path, "embedded", TRUE, "intent", VIPS_INTENT_PERCEPTUAL, NULL);
-        	// ignore embedded errors
-        	if (result != 0) {
-        		result = 0;
-        		*out = in;
-        	}
-    	}
-    } else {
-			result = vips_icc_transform(in, out, gray_profile_path, "input_profile", gray_profile_path, "embedded", TRUE, "intent", VIPS_INTENT_PERCEPTUAL, NULL);
-    }
-
-    return result;
+int icc_transform(VipsImage *in, VipsImage **out, const char *output_profile, const char *input_profile, VipsIntent intent,
+	int depth, gboolean embedded) {
+	return vips_icc_transform(
+    	in, out, output_profile,
+    	"input_profile", input_profile ? input_profile : "none",
+    	"intent", intent,
+    	"depth", depth ? depth : 8,
+    	"embedded", embedded,
+    	NULL);
 }

vips/color.go

@@ -3,6 +3,7 @@ package vips
 // #cgo pkg-config: vips
 // #include "color.h"
 import "C"
+import "unsafe"
 
 // Color represents an RGB
 type Color struct {
@@ -37,6 +38,18 @@ const (
 	InterpretationHSV       Interpretation = C.VIPS_INTERPRETATION_HSV
 )
 
+// Interpretation represents VIPS_INTENT type
+type Intent int
+
+//Intent enum
+const (
+	IntentPerceptual Intent = C.VIPS_INTENT_PERCEPTUAL
+	IntentRelative   Intent = C.VIPS_INTENT_RELATIVE
+	IntentSaturation Intent = C.VIPS_INTENT_SATURATION
+	IntentAbsolute   Intent = C.VIPS_INTENT_ABSOLUTE
+	IntentLast       Intent = C.VIPS_INTENT_LAST
+)
+
 func vipsIsColorSpaceSupported(in *C.VipsImage) bool {
 	return C.is_colorspace_supported(in) == 1
 }
@@ -46,19 +59,32 @@ func vipsToColorSpace(in *C.VipsImage, interpretation Interpretation) (*C.VipsIm
 	incOpCounter("to_colorspace")
 	var out *C.VipsImage
 
-	inter := C.VipsInterpretation(interpretation)
-
-	if err := C.to_colorspace(in, &out, inter); err != 0 {
+	if res := C.to_colorspace(in, &out, C.VipsInterpretation(interpretation)); res != 0 {
 		return nil, handleImageError(out)
 	}
 
 	return out, nil
 }
 
-func vipsOptimizeICCProfile(in *C.VipsImage, isCmyk int) (*C.VipsImage, error) {
+func vipsICCTransform(in *C.VipsImage, outputProfile string, inputProfile string, intent Intent, depth int,
+	embedded bool) (*C.VipsImage, error) {
 	var out *C.VipsImage
+	var cInputProfile *C.char
+	var cEmbedded C.gboolean
+
+	cOutputProfile := C.CString(outputProfile)
+	defer C.free(unsafe.Pointer(cOutputProfile))
+
+	if inputProfile != "" {
+		cInputProfile = C.CString(inputProfile)
+		defer C.free(unsafe.Pointer(cInputProfile))
+	}
+
+	if embedded {
+		cEmbedded = C.TRUE
+	}
 
-	if res := int(C.optimize_icc_profile(in, &out, C.int(isCmyk))); res != 0 {
+	if res := C.icc_transform(in, &out, cOutputProfile, cInputProfile, C.VipsIntent(intent), C.int(depth), cEmbedded); res != 0 {
 		return nil, handleImageError(out)
 	}
 

vips/color.h

@@ -6,4 +6,5 @@
 int is_colorspace_supported(VipsImage *in);
 int to_colorspace(VipsImage *in, VipsImage **out, VipsInterpretation space);
 
-int optimize_icc_profile(VipsImage *in, VipsImage **out, int isCmyk);
+int icc_transform(VipsImage *in, VipsImage **out, const char *output_profile, const char *input_profile,
+	VipsIntent intent, int depth, gboolean embedded);

vips/foreign.c

@@ -1,5 +1,6 @@
 #include "lang.h"
 #include "foreign.h"
+#include "icc_profiles.h"
 
 int load_image_buffer(void *buf, size_t len, int imageType, VipsImage **out) {
 	int code = 1;
@@ -55,12 +56,15 @@ int save_png_buffer(VipsImage *in, void **buf, size_t *len, int strip, int compr
 // todo: support additional params
 // https://github.com/libvips/libvips/blob/master/libvips/foreign/webpsave.c#L524
 // https://libvips.github.io/libvips/API/current/VipsForeignSave.html#vips-webpsave-buffer
-int save_webp_buffer(VipsImage *in, void **buf, size_t *len, int strip, int quality, int lossless, int effort) {
+int save_webp_buffer(VipsImage *in, void **buf, size_t *len, int strip, int quality, int lossless, int near_lossless,
+	int effort, const char *profile) {
 	return vips_webpsave_buffer(in, buf, len,
 		"strip", INT_TO_GBOOLEAN(strip),
 		"Q", quality,
 		"lossless", INT_TO_GBOOLEAN(lossless),
+		"near_lossless", INT_TO_GBOOLEAN(near_lossless),
 		"reduction_effort", effort,
+		"profile", profile ? profile : "none",
 		NULL
 	);
 }

vips/foreign.go

@@ -237,17 +237,21 @@ func vipsSavePNGToBuffer(in *C.VipsImage, stripMetadata bool, compression int, i
 	return toBuff(ptr, cLen), nil
 }
 
-func vipsSaveWebPToBuffer(in *C.VipsImage, stripMetadata bool, quality int, lossless bool, effort int) ([]byte, error) {
+func vipsSaveWebPToBuffer(in *C.VipsImage, stripMetadata bool, quality int, lossless bool, nearLossless bool,
+	effort int, profile string) ([]byte, error) {
 	incOpCounter("save_webp_buffer")
 	var ptr unsafe.Pointer
-	cLen := C.size_t(0)
+	var cProfile *C.char
+	var cLen C.size_t
 
-	strip := C.int(boolToInt(stripMetadata))
-	qual := C.int(quality)
-	loss := C.int(boolToInt(lossless))
-	eff := C.int(effort)
+	if profile != "" {
+		cProfile = C.CString(profile)
+		defer C.free(unsafe.Pointer(cProfile))
+	}
 
-	if err := C.save_webp_buffer(in, &ptr, &cLen, strip, qual, loss, eff); err != 0 {
+	if err := C.save_webp_buffer(
+		in, &ptr, &cLen, C.int(boolToInt(stripMetadata)), C.int(quality), C.int(boolToInt(lossless)),
+		C.int(boolToInt(nearLossless)), C.int(effort), cProfile); err != 0 {
 		return nil, handleSaveBufferError(ptr)
 	}
 

vips/foreign.h

@@ -23,6 +23,7 @@ int load_image_buffer(void *buf, size_t len, int imageType, VipsImage **out);
 
 int save_jpeg_buffer(VipsImage* image, void **buf, size_t *len, int strip, int quality, int interlace);
 int save_png_buffer(VipsImage *in, void **buf, size_t *len, int strip, int compression, int interlace);
-int save_webp_buffer(VipsImage *in, void **buf, size_t *len, int strip, int quality, int lossless, int effort);
+int save_webp_buffer(VipsImage *in, void **buf, size_t *len, int strip, int quality, int lossless, int near_lossless,
+	int effort, const char *profile);
 int save_heif_buffer(VipsImage *in, void **buf, size_t *len, int quality, int lossless);
 int save_tiff_buffer(VipsImage *in, void **buf, size_t *len);

vips/image.go

@@ -2,6 +2,7 @@ package vips
 
 // #cgo pkg-config: vips
 // #include "image.h"
+// #include "icc_profiles.h"
 import "C"
 
 import (
@@ -23,11 +24,12 @@ type ImageRef struct {
 	// NOTE: We keep a reference to this so that the input buffer is
 	// never garbage collected during processing. Some image loaders use random
 	// access transcoding and therefore need the original buffer to be in memory.
-	buf               []byte
-	image             *C.VipsImage
-	format            ImageType
-	lock              sync.Mutex
-	preMultiplication *PreMultiplicationState
+	buf                 []byte
+	image               *C.VipsImage
+	format              ImageType
+	lock                sync.Mutex
+	preMultiplication   *PreMultiplicationState
+	optimizedIccProfile string
 }
 
 type ImageMetadata struct {
@@ -40,12 +42,13 @@ type ImageMetadata struct {
 
 // ExportParams are options when exporting an image to file or buffer
 type ExportParams struct {
-	Format      ImageType
-	Quality     int
-	Compression int
-	Interlaced  bool
-	Lossless    bool
-	Effort      int
+	Format       ImageType
+	Quality      int
+	Compression  int
+	Interlaced   bool
+	Lossless     bool
+	NearLossless bool
+	Effort       int
 }
 
 func NewDefaultExportParams() *ExportParams {
@@ -77,10 +80,11 @@ func NewDefaultPNGExportParams() *ExportParams {
 
 func NewDefaultWEBPExportParams() *ExportParams {
 	return &ExportParams{
-		Format:   ImageTypeWEBP,
-		Quality:  75,
-		Lossless: false,
-		Effort:   4,
+		Format:       ImageTypeWEBP,
+		Quality:      75,
+		Lossless:     false,
+		NearLossless: false,
+		Effort:       4,
 	}
 }
 
@@ -275,26 +279,10 @@ func (r *ImageRef) IsColorSpaceSupported() bool {
 
 // Export exports the image
 func (r *ImageRef) Export(params *ExportParams) ([]byte, *ImageMetadata, error) {
-	p := params
-	if p == nil {
-		switch r.format {
-		case ImageTypeJPEG:
-			p = NewDefaultJPEGExportParams()
-		case ImageTypePNG:
-			p = NewDefaultPNGExportParams()
-		case ImageTypeWEBP:
-			p = NewDefaultWEBPExportParams()
-		default:
-			p = NewDefaultExportParams()
-		}
-	}
-
-	if p.Format == ImageTypeUnknown {
-		p.Format = r.format
-	}
+	params = r.resolveExportParams(params)
 
 	// the exported buf is not necessarily in same format as the original buf, might default to JPEG as well.
-	buf, format, err := r.exportBuffer(p)
+	buf, format, err := r.exportBuffer(params)
 	if err != nil {
 		return nil, nil, err
 	}
@@ -310,6 +298,27 @@ func (r *ImageRef) Export(params *ExportParams) ([]byte, *ImageMetadata, error)
 	return buf, metadata, nil
 }
 
+func (r *ImageRef) resolveExportParams(params *ExportParams) *ExportParams {
+	if params == nil {
+		switch r.format {
+		case ImageTypeJPEG:
+			params = NewDefaultJPEGExportParams()
+		case ImageTypePNG:
+			params = NewDefaultPNGExportParams()
+		case ImageTypeWEBP:
+			params = NewDefaultWEBPExportParams()
+		default:
+			params = NewDefaultExportParams()
+		}
+	}
+
+	if params.Format == ImageTypeUnknown {
+		params.Format = r.format
+	}
+
+	return params
+}
+
 func (r *ImageRef) Composite(overlay *ImageRef, mode BlendMode, x, y int) error {
 	out, err := vipsComposite2(r.image, overlay.image, mode, x, y)
 	if err != nil {
@@ -464,16 +473,25 @@ func (r *ImageRef) RemoveICCProfile() error {
 }
 
 func (r *ImageRef) OptimizeICCProfile() error {
-	isCMYK := 0
-	if r.Interpretation() == InterpretationCMYK {
-		isCMYK = 1
+	inputProfile := r.determineInputICCProfile()
+	if !r.HasICCProfile() && (inputProfile == "") {
+		//No embedded ICC profile in the input image and no input profile determined, nothing to do.
+		return nil
 	}
 
-	out, err := vipsOptimizeICCProfile(r.image, isCMYK)
+	r.optimizedIccProfile = C.GoString(C.SRGB_V2_MICRO_ICC_PATH)
+	if r.Bands() <= 2 {
+		r.optimizedIccProfile = C.GoString(C.SGRAY_V2_MICRO_ICC_PATH)
+	}
+
+	embedded := r.HasICCProfile() && (inputProfile == "")
+
+	out, err := vipsICCTransform(r.image, r.optimizedIccProfile, inputProfile, IntentPerceptual, 0, embedded)
 	if err != nil {
 		info(err.Error())
 		return err
 	}
+
 	r.setImage(out)
 	return nil
 }
@@ -702,6 +720,13 @@ func (r *ImageRef) ToBytes() ([]byte, error) {
 	return bytes, nil
 }
 
+func (r *ImageRef) determineInputICCProfile() (inputProfile string) {
+	if r.Interpretation() == InterpretationCMYK {
+		inputProfile = "cmyk"
+	}
+	return
+}
+
 // setImage resets the image for this image and frees the previous one
 func (r *ImageRef) setImage(image *C.VipsImage) {
 	r.lock.Lock()
@@ -729,7 +754,8 @@ func (r *ImageRef) exportBuffer(params *ExportParams) ([]byte, ImageType, error)
 
 	switch format {
 	case ImageTypeWEBP:
-		buf, err = vipsSaveWebPToBuffer(r.image, false, params.Quality, params.Lossless, params.Effort)
+		buf, err = vipsSaveWebPToBuffer(r.image, false, params.Quality, params.Lossless, params.NearLossless,
+			params.Effort, r.optimizedIccProfile)
 	case ImageTypePNG:
 		buf, err = vipsSavePNGToBuffer(r.image, false, params.Compression, params.Interlaced)
 	case ImageTypeTIFF: