Watermark

config.go

@@ -20,6 +20,12 @@ func intEnvConfig(i *int, name string) {
 	}
 }
 
+func floatEnvConfig(i *float64, name string) {
+	if env, err := strconv.ParseFloat(os.Getenv(name), 64); err == nil {
+		*i = env
+	}
+}
+
 func megaIntEnvConfig(f *int, name string) {
 	if env, err := strconv.ParseFloat(os.Getenv(name), 64); err == nil {
 		*f = int(env * 1000000)
@@ -144,6 +150,11 @@ type config struct {
 	BaseURL string
 
 	Presets presets
+
+	WatermarkData    string
+	WatermarkPath    string
+	WatermarkURL     string
+	WatermarkOpacity float64
 }
 
 var conf = config{
@@ -161,6 +172,7 @@ var conf = config{
 	GZipCompression:       5,
 	ETagEnabled:           false,
 	S3Enabled:             false,
+	WatermarkOpacity:      1,
 }
 
 func init() {
@@ -223,6 +235,11 @@ func init() {
 	presetEnvConfig(conf.Presets, "IMGPROXY_PRESETS")
 	presetFileConfig(conf.Presets, *presetsPath)
 
+	strEnvConfig(&conf.WatermarkData, "IMGPROXY_WATERMARK_DATA")
+	strEnvConfig(&conf.WatermarkPath, "IMGPROXY_WATERMARK_PATH")
+	strEnvConfig(&conf.WatermarkURL, "IMGPROXY_WATERMARK_URL")
+	floatEnvConfig(&conf.WatermarkOpacity, "IMGPROXY_WATERMARK_OPACITY")
+
 	if len(conf.Key) == 0 {
 		warning("Key is not defined, so signature checking is disabled")
 		conf.AllowInsecure = true
@@ -300,6 +317,12 @@ func init() {
 
 	checkPresets(conf.Presets)
 
-	initVips()
+	if conf.WatermarkOpacity <= 0 {
+		log.Fatalln("Watermark opacity should be greater than 0")
+	} else if conf.WatermarkOpacity > 1 {
+		log.Fatalln("Watermark opacity should be less than or equal to 1")
+	}
+
 	initDownloading()
+	initVips()
 }

process.go

@@ -22,6 +22,8 @@ var (
 	vipsTypeSupportLoad  = make(map[imageType]bool)
 	vipsTypeSupportSave  = make(map[imageType]bool)
 
+	watermark *C.struct__VipsImage
+
 	errSmartCropNotSupported = errors.New("Smart crop is not supported by used version of libvips")
 )
 
@@ -29,6 +31,7 @@ type cConfig struct {
 	Quality          C.int
 	JpegProgressive  C.int
 	PngInterlaced    C.int
+	WatermarkOpacity C.double
 }
 
 var cConf cConfig
@@ -89,9 +92,16 @@ func initVips() {
 	if conf.PngInterlaced {
 		cConf.PngInterlaced = C.int(1)
 	}
+
+	cConf.WatermarkOpacity = C.double(conf.WatermarkOpacity)
+
+	if err := vipsPrepareWatermark(); err != nil {
+		log.Fatal(err)
+	}
 }
 
 func shutdownVips() {
+	C.clear_image(&watermark)
 	C.vips_shutdown()
 }
 
@@ -174,31 +184,33 @@ func calcShink(scale float64, imgtype imageType) int {
 }
 
 func calcCrop(width, height int, po *processingOptions) (left, top int) {
-	left = (width - po.Width + 1) / 2
-	top = (height - po.Height + 1) / 2
-
-	if po.Gravity.Type == gravityNorth {
-		top = 0
-	}
-
-	if po.Gravity.Type == gravityEast {
-		left = width - po.Width
-	}
-
-	if po.Gravity.Type == gravitySouth {
-		top = height - po.Height
-	}
-
-	if po.Gravity.Type == gravityWest {
-		left = 0
-	}
-
 	if po.Gravity.Type == gravityFocusPoint {
 		pointX := int(float64(width) * po.Gravity.X)
 		pointY := int(float64(height) * po.Gravity.Y)
 
 		left = maxInt(0, minInt(pointX-po.Width/2, width-po.Width))
 		top = maxInt(0, minInt(pointY-po.Height/2, height-po.Height))
+
+		return
+	}
+
+	left = (width - po.Width + 1) / 2
+	top = (height - po.Height + 1) / 2
+
+	if po.Gravity.Type == gravityNorth || po.Gravity.Type == gravityNorthEast || po.Gravity.Type == gravityNorthWest {
+		top = 0
+	}
+
+	if po.Gravity.Type == gravityEast || po.Gravity.Type == gravityNorthEast || po.Gravity.Type == gravitySouthEast {
+		left = width - po.Width
+	}
+
+	if po.Gravity.Type == gravitySouth || po.Gravity.Type == gravitySouthEast || po.Gravity.Type == gravitySouthWest {
+		top = height - po.Height
+	}
+
+	if po.Gravity.Type == gravityWest || po.Gravity.Type == gravityNorthWest || po.Gravity.Type == gravitySouthWest {
+		left = 0
 	}
 
 	return
@@ -354,9 +366,73 @@ func processImage(ctx context.Context) ([]byte, error) {
 
 	checkTimeout(ctx)
 
+	if po.Watermark.Enabled {
+		if err = vipsApplyWatermark(&img, &po.Watermark); err != nil {
+			return nil, err
+		}
+	}
+
 	return vipsSaveImage(img, po.Format)
 }
 
+func vipsPrepareWatermark() error {
+	data, imgtype, cancel, err := watermarkData()
+	defer cancel()
+
+	if err != nil {
+		return err
+	}
+
+	if data == nil {
+		return nil
+	}
+
+	if C.vips_load_buffer(unsafe.Pointer(&data[0]), C.size_t(len(data)), C.int(imgtype), 1, &watermark) != 0 {
+		return vipsError()
+	}
+
+	var tmp *C.struct__VipsImage
+
+	if cConf.WatermarkOpacity < 1 {
+		if vipsImageHasAlpha(watermark) {
+			var alpha *C.struct__VipsImage
+			defer C.clear_image(&alpha)
+
+			if C.vips_extract_band_go(watermark, &tmp, (*watermark).Bands-1, 1) != 0 {
+				return vipsError()
+			}
+			C.swap_and_clear(&alpha, tmp)
+
+			if C.vips_extract_band_go(watermark, &tmp, 0, (*watermark).Bands-1) != 0 {
+				return vipsError()
+			}
+			C.swap_and_clear(&watermark, tmp)
+
+			if C.vips_linear_go(alpha, &tmp, cConf.WatermarkOpacity, 0) != 0 {
+				return vipsError()
+			}
+			C.swap_and_clear(&alpha, tmp)
+
+			if C.vips_bandjoin_go(watermark, alpha, &tmp) != 0 {
+				return vipsError()
+			}
+			C.swap_and_clear(&watermark, tmp)
+		} else {
+			if C.vips_bandjoin_const_go(watermark, &tmp, cConf.WatermarkOpacity*255) != 0 {
+				return vipsError()
+			}
+			C.swap_and_clear(&watermark, tmp)
+		}
+	}
+
+	if tmp = C.vips_image_copy_memory(watermark); tmp == nil {
+		return vipsError()
+	}
+	C.swap_and_clear(&watermark, tmp)
+
+	return nil
+}
+
 func vipsLoadImage(data []byte, imgtype imageType, shrink int) (*C.struct__VipsImage, error) {
 	var img *C.struct__VipsImage
 	if C.vips_load_buffer(unsafe.Pointer(&data[0]), C.size_t(len(data)), C.int(imgtype), C.int(shrink), &img) != 0 {
@@ -549,6 +625,145 @@ func vipsImageCopyMemory(img **C.struct__VipsImage) error {
 	return nil
 }
 
+func vipsReplicateWatermark(width, height C.int) (wm *C.struct__VipsImage, err error) {
+	var tmp *C.struct__VipsImage
+	defer C.clear_image(&tmp)
+
+	if C.vips_replicate_go(watermark, &tmp, 1+width/watermark.Xsize, 1+height/watermark.Ysize) != 0 {
+		err = vipsError()
+		return
+	}
+
+	if C.vips_extract_area_go(tmp, &wm, 0, 0, width, height) != 0 {
+		err = vipsError()
+		return
+	}
+
+	return
+}
+
+func vipsEmbedWatermark(gravity gravityType, width, height C.int, offX, offY C.int) (wm *C.struct__VipsImage, err error) {
+	wmWidth := watermark.Xsize
+	wmHeight := watermark.Ysize
+
+	left := (width-wmWidth+1)/2 + offX
+	top := (height-wmHeight+1)/2 + offY
+
+	if gravity == gravityNorth || gravity == gravityNorthEast || gravity == gravityNorthWest {
+		top = offY
+	}
+
+	if gravity == gravityEast || gravity == gravityNorthEast || gravity == gravitySouthEast {
+		left = width - wmWidth - offX
+	}
+
+	if gravity == gravitySouth || gravity == gravitySouthEast || gravity == gravitySouthWest {
+		top = height - wmHeight - offY
+	}
+
+	if gravity == gravityWest || gravity == gravityNorthWest || gravity == gravitySouthWest {
+		left = offX
+	}
+
+	if left > width {
+		left = width - wmWidth
+	} else if left < -wmWidth {
+		left = 0
+	}
+
+	if top > height {
+		top = height - wmHeight
+	} else if top < -wmHeight {
+		top = 0
+	}
+
+	if C.vips_embed_go(watermark, &wm, left, top, width, height) != 0 {
+		err = vipsError()
+		return
+	}
+
+	return
+}
+
+func vipsApplyWatermark(img **C.struct__VipsImage, opts *watermarkOptions) error {
+	if watermark == nil {
+		return nil
+	}
+
+	var wm, wmAlpha, tmp *C.struct__VipsImage
+	var err error
+
+	defer C.clear_image(&wm)
+	defer C.clear_image(&wmAlpha)
+
+	imgW := (*img).Xsize
+	imgH := (*img).Ysize
+
+	if opts.Replicate {
+		if wm, err = vipsReplicateWatermark(imgW, imgH); err != nil {
+			return err
+		}
+	} else {
+		if wm, err = vipsEmbedWatermark(opts.Gravity, imgW, imgH, C.int(opts.OffsetX), C.int(opts.OffsetY)); err != nil {
+			return err
+		}
+	}
+
+	if C.vips_extract_band_go(wm, &tmp, (*wm).Bands-1, 1) != 0 {
+		return vipsError()
+	}
+	C.swap_and_clear(&wmAlpha, tmp)
+
+	if C.vips_extract_band_go(wm, &tmp, 0, (*wm).Bands-1) != 0 {
+		return vipsError()
+	}
+	C.swap_and_clear(&wm, tmp)
+
+	if C.vips_image_guess_interpretation(*img) != C.vips_image_guess_interpretation(wm) {
+		if C.vips_colourspace_go(wm, &tmp, C.vips_image_guess_interpretation(*img)) != 0 {
+			return vipsError()
+		}
+		C.swap_and_clear(&wm, tmp)
+	}
+
+	if opts.Opacity < 1 {
+		if C.vips_linear_go(wmAlpha, &tmp, C.double(opts.Opacity), 0) != 0 {
+			return vipsError()
+		}
+		C.swap_and_clear(&wmAlpha, tmp)
+	}
+
+	var imgAlpha *C.struct__VipsImage
+	defer C.clear_image(&imgAlpha)
+
+	hasAlpha := vipsImageHasAlpha(*img)
+
+	if hasAlpha {
+		if C.vips_extract_band_go(*img, &imgAlpha, (**img).Bands-1, 1) != 0 {
+			return vipsError()
+		}
+
+		if C.vips_extract_band_go(*img, &tmp, 0, (**img).Bands-1) != 0 {
+			return vipsError()
+		}
+		C.swap_and_clear(img, tmp)
+	}
+
+	if C.vips_ifthenelse_go(wmAlpha, wm, *img, &tmp) != 0 {
+		return vipsError()
+	}
+	C.swap_and_clear(img, tmp)
+
+	if hasAlpha {
+		if C.vips_bandjoin_go(*img, imgAlpha, &tmp) != 0 {
+			return vipsError()
+		}
+		C.swap_and_clear(img, tmp)
+	}
+
+	return nil
+}
+
 func vipsError() error {
 	return errors.New(C.GoString(C.vips_error_buffer()))
 }

processing_options.go

@@ -47,6 +47,10 @@ const (
 	gravityEast
 	gravitySouth
 	gravityWest
+	gravityNorthWest
+	gravityNorthEast
+	gravitySouthWest
+	gravitySouthEast
 	gravitySmart
 	gravityFocusPoint
 )
@@ -57,11 +61,15 @@ var gravityTypes = map[string]gravityType{
 	"ea":   gravityEast,
 	"so":   gravitySouth,
 	"we":   gravityWest,
+	"nowe": gravityNorthWest,
+	"noea": gravityNorthEast,
+	"sowe": gravitySouthWest,
+	"soea": gravitySouthEast,
 	"sm":   gravitySmart,
 	"fp":   gravityFocusPoint,
 }
 
-type gravity struct {
+type gravityOptions struct {
 	Type gravityType
 	X, Y float64
 }
@@ -89,17 +97,29 @@ const (
 	hexColorShortFormat = "%1x%1x%1x"
 )
 
+type watermarkOptions struct {
+	Enabled   bool
+	Opacity   float64
+	Replicate bool
+	Gravity   gravityType
+	OffsetX   int
+	OffsetY   int
+}
+
 type processingOptions struct {
 	Resize     resizeType
 	Width      int
 	Height     int
-	Gravity     gravity
+	Gravity    gravityOptions
 	Enlarge    bool
 	Format     imageType
 	Flatten    bool
 	Background color
 	Blur       float32
 	Sharpen    float32
+
+	Watermark watermarkOptions
+
 	UsedPresets []string
 }
 
@@ -411,6 +431,43 @@ func applyPresetOption(po *processingOptions, args []string) error {
 	return nil
 }
 
+func applyWatermarkOption(po *processingOptions, args []string) error {
+	if o, err := strconv.ParseFloat(args[0], 64); err == nil && o >= 0 && o <= 1 {
+		po.Watermark.Enabled = o > 0
+		po.Watermark.Opacity = o
+	} else {
+		return fmt.Errorf("Invalid watermark opacity: %s", args[0])
+	}
+
+	if len(args) > 1 {
+		if args[1] == "re" {
+			po.Watermark.Replicate = true
+		} else if g, ok := gravityTypes[args[1]]; ok && g != gravityFocusPoint {
+			po.Watermark.Gravity = g
+		} else {
+			return fmt.Errorf("Invalid watermark position: %s", args[1])
+		}
+	}
+
+	if len(args) > 2 {
+		if x, err := strconv.Atoi(args[2]); err == nil {
+			po.Watermark.OffsetX = x
+		} else {
+			return fmt.Errorf("Invalid watermark X offset: %s", args[2])
+		}
+	}
+
+	if len(args) > 3 {
+		if y, err := strconv.Atoi(args[3]); err == nil {
+			po.Watermark.OffsetY = y
+		} else {
+			return fmt.Errorf("Invalid watermark Y offset: %s", args[3])
+		}
+	}
+
+	return nil
+}
+
 func applyFormatOption(po *processingOptions, args []string) error {
 	if len(args) > 1 {
 		return fmt.Errorf("Invalid format arguments: %v", args)
@@ -480,6 +537,10 @@ func applyProcessingOption(po *processingOptions, name string, args []string) er
 		if err := applySharpenOption(po, args); err != nil {
 			return err
 		}
+	case "watermark", "wm":
+		if err := applyWatermarkOption(po, args); err != nil {
+			return err
+		}
 	case "preset", "pr":
 		if err := applyPresetOption(po, args); err != nil {
 			return err
@@ -534,11 +595,12 @@ func defaultProcessingOptions(acceptHeader string) (*processingOptions, error) {
 		Resize:      resizeFit,
 		Width:       0,
 		Height:      0,
-		Gravity:     gravity{Type: gravityCenter},
+		Gravity:     gravityOptions{Type: gravityCenter},
 		Enlarge:     false,
 		Format:      imageTypeJPEG,
 		Blur:        0,
 		Sharpen:     0,
+		Watermark:   watermarkOptions{Opacity: 1, Replicate: false, Gravity: gravityCenter},
 		UsedPresets: make([]string, 0, len(conf.Presets)),
 	}
 

vips.h

@@ -203,6 +203,41 @@ vips_extract_area_go(VipsImage *in, VipsImage **out, int left, int top, int widt
   return vips_extract_area(in, out, left, top, width, height, NULL);
 }
 
+int
+vips_replicate_go(VipsImage *in, VipsImage **out, int across, int down) {
+  return vips_replicate(in, out, across, down, NULL);
+}
+
+int
+vips_embed_go(VipsImage *in, VipsImage **out, int x, int y, int width, int height) {
+  return vips_embed(in, out, x, y, width, height, NULL);
+}
+
+int
+vips_extract_band_go(VipsImage *in, VipsImage **out, int band, int band_num) {
+  return vips_extract_band(in, out, band, "n", band_num, NULL);
+}
+
+int
+vips_bandjoin_go (VipsImage *in1, VipsImage *in2, VipsImage **out) {
+  return vips_bandjoin2(in1, in2, out, NULL);
+}
+
+int
+vips_bandjoin_const_go (VipsImage *in, VipsImage **out, double c) {
+  return vips_bandjoin_const1(in, out, c, NULL);
+}
+
+int
+vips_linear_go (VipsImage *in, VipsImage **out, double a, double b) {
+  return vips_linear1(in, out, a, b, NULL);
+}
+
+int
+vips_ifthenelse_go(VipsImage *cond, VipsImage *in1, VipsImage *in2, VipsImage **out) {
+  return vips_ifthenelse(cond, in1, in2, out, "blend", TRUE, NULL);
+}
+
 int
 vips_jpegsave_go(VipsImage *in, void **buf, size_t *len, int strip, int quality, int interlace) {
   return vips_jpegsave_buffer(in, buf, len, "strip", strip, "Q", quality, "optimize_coding", TRUE, "interlace", interlace, NULL);

watermark_data.go

@@ -0,0 +1,75 @@
+package main
+
+import (
+	"bytes"
+	"context"
+	"encoding/base64"
+	"fmt"
+	"io/ioutil"
+	"os"
+)
+
+func watermarkData() ([]byte, imageType, context.CancelFunc, error) {
+	if len(conf.WatermarkData) > 0 {
+		data, imgtype, err := base64WatermarkData()
+		return data, imgtype, func() {}, err
+	}
+
+	if len(conf.WatermarkPath) > 0 {
+		data, imgtype, err := fileWatermarkData()
+		return data, imgtype, func() {}, err
+	}
+
+	if len(conf.WatermarkURL) > 0 {
+		return remoteWatermarkData()
+	}
+
+	return nil, imageTypeUnknown, func() {}, nil
+}
+
+func base64WatermarkData() ([]byte, imageType, error) {
+	data, err := base64.StdEncoding.DecodeString(conf.WatermarkData)
+	if err != nil {
+		return nil, imageTypeUnknown, fmt.Errorf("Can't decode watermark data: %s", err)
+	}
+
+	imgtype, err := checkTypeAndDimensions(bytes.NewReader(data))
+	if err != nil {
+		return nil, imageTypeUnknown, fmt.Errorf("Can't decode watermark: %s", err)
+	}
+
+	return data, imgtype, nil
+}
+
+func fileWatermarkData() ([]byte, imageType, error) {
+	f, err := os.Open(conf.WatermarkPath)
+	if err != nil {
+		return nil, imageTypeUnknown, fmt.Errorf("Can't read watermark: %s", err)
+	}
+
+	imgtype, err := checkTypeAndDimensions(f)
+	if err != nil {
+		return nil, imageTypeUnknown, fmt.Errorf("Can't decode watermark: %s", err)
+	}
+
+	// Return to the beginning of the file
+	f.Seek(0, 0)
+
+	data, err := ioutil.ReadAll(f)
+	if err != nil {
+		return nil, imageTypeUnknown, fmt.Errorf("Can't read watermark: %s", err)
+	}
+
+	return data, imgtype, nil
+}
+
+func remoteWatermarkData() ([]byte, imageType, context.CancelFunc, error) {
+	ctx := context.WithValue(context.Background(), imageURLCtxKey, conf.WatermarkURL)
+	ctx, cancel, err := downloadImage(ctx)
+
+	if err != nil {
+		return nil, imageTypeUnknown, cancel, fmt.Errorf("Can't download watermark: %s", err)
+	}
+
+	return getImageData(ctx).Bytes(), getImageType(ctx), cancel, err
+}