Add option to keep metadata/tags in output image (#329)

* add env var to disable stripping metadata

by default, all metadata will be stripped (as before)

* always strip orientation tags when rotating the image

in case IMGPROXY_STRIP_METADATA is false

* document IMGPROXY_STRIP_METADATA env var

* remove ICC profile after importing it

needed, in case metadata aren't stripped from the output image

config.go

@@ -166,6 +166,7 @@ type config struct {
 	PngQuantizationColors int
 	Quality               int
 	GZipCompression       int
+	StripMetadata         bool
 
 	EnableWebpDetection bool
 	EnforceWebp         bool
@@ -242,6 +243,7 @@ var conf = config{
 	SignatureSize:                  32,
 	PngQuantizationColors:          256,
 	Quality:                        80,
+	StripMetadata:                  true,
 	UserAgent:                      fmt.Sprintf("imgproxy/%s", version),
 	Presets:                        make(presets),
 	WatermarkOpacity:               1,
@@ -300,6 +302,7 @@ func configure() {
 	intEnvConfig(&conf.PngQuantizationColors, "IMGPROXY_PNG_QUANTIZATION_COLORS")
 	intEnvConfig(&conf.Quality, "IMGPROXY_QUALITY")
 	intEnvConfig(&conf.GZipCompression, "IMGPROXY_GZIP_COMPRESSION")
+	boolEnvConfig(&conf.StripMetadata, "IMGPROXY_STRIP_METADATA")
 
 	boolEnvConfig(&conf.EnableWebpDetection, "IMGPROXY_ENABLE_WEBP_DETECTION")
 	boolEnvConfig(&conf.EnforceWebp, "IMGPROXY_ENFORCE_WEBP")

docs/configuration.md

@@ -253,3 +253,4 @@ imgproxy can send logs to syslog, but this feature is disabled by default. To en
 * `IMGPROXY_USE_LINEAR_COLORSPACE`: when `true`, imgproxy will process images in linear colorspace. This will slow down processing. Note that images won't be fully processed in linear colorspace while shrink-on-load is enabled (see below).
 * `IMGPROXY_DISABLE_SHRINK_ON_LOAD`: when `true`, disables shrink-on-load for JPEG and WebP. Allows to process the whole image in linear colorspace but dramatically slows down resizing and increases memory usage when working with large images.
 * `IMGPROXY_APPLY_UNSHARPEN_MASKING`: <img class="pro-badge" src="assets/pro.svg" alt="pro" /> when `true`, imgproxy will apply unsharpen masking to the resulting image if one is smaller than the source. Default: `true`.
+* `IMGPROXY_STRIP_METADATA`: whether to strip all metadata (EXIF, IPTC, etc.) from JPEG and WebP output images. Default: `true`.

process.go

@@ -609,7 +609,7 @@ func saveImageToFitBytes(po *processingOptions, img *vipsImage) ([]byte, context
 	img.CopyMemory()
 
 	for {
-		result, cancel, err := img.Save(po.Format, quality)
+		result, cancel, err := img.Save(po.Format, quality, po.StripMetadata)
 		if len(result) <= po.MaxBytes || quality <= 10 || err != nil {
 			return result, cancel, err
 		}
@@ -737,5 +737,5 @@ func processImage(ctx context.Context) ([]byte, context.CancelFunc, error) {
 		return saveImageToFitBytes(po, img)
 	}
 
-	return img.Save(po.Format, po.Quality)
+	return img.Save(po.Format, po.Quality, po.StripMetadata)
 }

processing_options.go

@@ -125,6 +125,7 @@ type processingOptions struct {
 	Trim          trimOptions
 	Format        imageType
 	Quality       int
+	StripMetadata bool
 	MaxBytes      int
 	Flatten       bool
 	Background    rgbColor
@@ -206,6 +207,7 @@ func newProcessingOptions() *processingOptions {
 			Extend:        extendOptions{Enabled: false, Gravity: gravityOptions{Type: gravityCenter}},
 			Trim:          trimOptions{Enabled: false, Threshold: 10},
 			Quality:       conf.Quality,
+			StripMetadata: conf.StripMetadata,
 			MaxBytes:      0,
 			Format:        imageTypeUnknown,
 			Background:    rgbColor{255, 255, 255},

vips.c

@@ -338,7 +338,12 @@ vips_support_builtin_icc() {
 
 int
 vips_icc_import_go(VipsImage *in, VipsImage **out, char *profile) {
-  return vips_icc_import(in, out, "input_profile", profile, "embedded", TRUE, "pcs", VIPS_PCS_XYZ, NULL);
+  if (vips_icc_import(in, out, "input_profile", profile, "embedded", TRUE, "pcs", VIPS_PCS_XYZ, NULL))
+    return 1;
+
+  vips_image_remove(*out, VIPS_META_ICC_NAME);
+
+  return 0;
 }
 
 int
@@ -512,8 +517,8 @@ vips_arrayjoin_go(VipsImage **in, VipsImage **out, int n) {
 }
 
 int
-vips_jpegsave_go(VipsImage *in, void **buf, size_t *len, int quality, int interlace) {
+vips_jpegsave_go(VipsImage *in, void **buf, size_t *len, int quality, int interlace, gboolean strip) {
-  return vips_jpegsave_buffer(in, buf, len, "profile", "none", "Q", quality, "strip", TRUE, "optimize_coding", TRUE, "interlace", interlace, NULL);
+  return vips_jpegsave_buffer(in, buf, len, "profile", "none", "Q", quality, "strip", strip, "optimize_coding", TRUE, "interlace", interlace, NULL);
 }
 
 int
@@ -531,8 +536,8 @@ vips_pngsave_go(VipsImage *in, void **buf, size_t *len, int interlace, int quant
 }
 
 int
-vips_webpsave_go(VipsImage *in, void **buf, size_t *len, int quality) {
+vips_webpsave_go(VipsImage *in, void **buf, size_t *len, int quality, gboolean strip) {
-  return vips_webpsave_buffer(in, buf, len, "Q", quality, "strip", TRUE, NULL);
+  return vips_webpsave_buffer(in, buf, len, "Q", quality, "strip", strip, NULL);
 }
 
 int

vips.go

@@ -130,6 +130,13 @@ func vipsLoadWatermark() (err error) {
 	return
 }
 
+func gbool(b bool) C.gboolean {
+	if b {
+		return C.gboolean(1)
+	}
+	return C.gboolean(0)
+}
+
 func (img *vipsImage) Width() int {
 	return int(img.VipsImage.Xsize)
 }
@@ -170,7 +177,7 @@ func (img *vipsImage) Load(data []byte, imgtype imageType, shrink int, scale flo
 	return nil
 }
 
-func (img *vipsImage) Save(imgtype imageType, quality int) ([]byte, context.CancelFunc, error) {
+func (img *vipsImage) Save(imgtype imageType, quality int, stripMeta bool) ([]byte, context.CancelFunc, error) {
 	var ptr unsafe.Pointer
 
 	cancel := func() {
@@ -183,11 +190,11 @@ func (img *vipsImage) Save(imgtype imageType, quality int) ([]byte, context.Canc
 
 	switch imgtype {
 	case imageTypeJPEG:
-		err = C.vips_jpegsave_go(img.VipsImage, &ptr, &imgsize, C.int(quality), vipsConf.JpegProgressive)
+		err = C.vips_jpegsave_go(img.VipsImage, &ptr, &imgsize, C.int(quality), vipsConf.JpegProgressive, gbool(stripMeta))
 	case imageTypePNG:
 		err = C.vips_pngsave_go(img.VipsImage, &ptr, &imgsize, vipsConf.PngInterlaced, vipsConf.PngQuantize, vipsConf.PngQuantizationColors)
 	case imageTypeWEBP:
-		err = C.vips_webpsave_go(img.VipsImage, &ptr, &imgsize, C.int(quality))
+		err = C.vips_webpsave_go(img.VipsImage, &ptr, &imgsize, C.int(quality), gbool(stripMeta))
 	case imageTypeGIF:
 		err = C.vips_gifsave_go(img.VipsImage, &ptr, &imgsize)
 	case imageTypeICO:
@@ -312,6 +319,8 @@ func (img *vipsImage) Rotate(angle int) error {
 		return vipsError()
 	}
 
+	C.vips_autorot_remove_angle(tmp)
+
 	C.swap_and_clear(&img.VipsImage, tmp)
 	return nil
 }

vips.h

@@ -82,9 +82,9 @@ int vips_apply_watermark(VipsImage *in, VipsImage *watermark, VipsImage **out, d
 
 int vips_arrayjoin_go(VipsImage **in, VipsImage **out, int n);
 
-int vips_jpegsave_go(VipsImage *in, void **buf, size_t *len, int quality, int interlace);
+int vips_jpegsave_go(VipsImage *in, void **buf, size_t *len, int quality, int interlace, gboolean strip);
 int vips_pngsave_go(VipsImage *in, void **buf, size_t *len, int interlace, int quantize, int colors);
-int vips_webpsave_go(VipsImage *in, void **buf, size_t *len, int quality);
+int vips_webpsave_go(VipsImage *in, void **buf, size_t *len, int quality, gboolean strip);
 int vips_gifsave_go(VipsImage *in, void **buf, size_t *len);
 int vips_icosave_go(VipsImage *in, void **buf, size_t *len);
 int vips_heifsave_go(VipsImage *in, void **buf, size_t *len, int quality);