Adding support for metadata in webp images.

Pillow now uses the webpmux library to envelop the webp images in RIFF. This allows for easy support of exif and icc_profile metadata.

Also included tests that verify compatibility with jpeg for exif and icc_profile metadata.

If the user does not have webp with webpmux enabled, pillow will fall back to the previous approach, meaning no exif or icc_profile metadata will be read or written to.

PIL/WebPImagePlugin.py

@@ -29,11 +29,19 @@ class WebPImageFile(ImageFile.ImageFile):
     format_description = "WebP image"
 
     def _open(self):
-        data, width, height, self.mode = _webp.WebPDecode(self.fp.read())
+        data, width, height, self.mode, icc_profile, exif = _webp.WebPDecode(self.fp.read())
+
+        self.info["icc_profile"] = icc_profile
+        self.info["exif"] = exif
+
         self.size = width, height
         self.fp = BytesIO(data)
         self.tile = [("raw", (0, 0) + self.size, 0, self.mode)]
 
+    def _getexif(self):
+        from PIL.JpegImagePlugin import JpegImageFile
+        return JpegImageFile._getexif.im_func(self)
+
 
 def _save(im, fp, filename):
     image_mode = im.mode
@@ -41,14 +49,21 @@ def _save(im, fp, filename):
         raise IOError("cannot write mode %s as WEBP" % image_mode)
 
     quality = im.encoderinfo.get("quality", 80)
+    icc_profile = im.encoderinfo.get("icc_profile", "")
+    exif = im.encoderinfo.get("exif", "")
 
     data = _webp.WebPEncode(
         im.tobytes(),
         im.size[0],
         im.size[1],
         float(quality),
-		im.mode
+        im.mode,
+        icc_profile,
+        exif
     )
+    if data is None:
+        raise IOError("cannot write file as WEBP (encoder returned None)")
+
     fp.write(data)
 
 

Tests/test_file_webp_metadata.py

@@ -0,0 +1,85 @@
+from tester import *
+
+from PIL import Image
+
+try:
+    from PIL import _webp
+    if not _webp.HAVE_WEBPMUX:
+        skip('webpmux support not installed')
+except:
+    skip('webp support not installed')
+
+try:
+    from StringIO import StringIO
+except ImportError:
+    from io import StringIO
+
+
+def test_read_exif_metadata():
+
+    file_path = "Images/flower.webp"
+    image = Image.open(file_path)
+
+    assert_equal(image.format, "WEBP")
+    exif_data = image.info.get("exif", None)
+    assert_true(exif_data)
+
+    exif = image._getexif()
+
+    #camera make
+    assert_equal(exif[271], "Canon")
+
+    jpeg_image = Image.open('Tests/images/flower.jpg')
+    expected_exif = jpeg_image.info['exif']
+
+    assert_equal(exif_data, expected_exif)
+
+
+def test_write_exif_metadata():
+    file_path = "Tests/images/flower.jpg"
+    image = Image.open(file_path)
+    expected_exif = image.info['exif']
+
+    buffer = StringIO()
+
+    image.save(buffer, "webp", exif=expected_exif)
+
+    buffer.seek(0)
+    webp_image = Image.open(buffer)
+
+    webp_exif = webp_image.info.get('exif', None)
+    assert_true(webp_exif)
+    assert_equal(webp_exif, expected_exif)
+
+
+def test_read_icc_profile():
+
+    file_path = "Images/flower2.webp"
+    image = Image.open(file_path)
+
+    assert_equal(image.format, "WEBP")
+    assert_true(image.info.get("icc_profile", None))
+
+    icc = image.info['icc_profile']
+
+    jpeg_image = Image.open('Tests/images/flower2.jpg')
+    expected_icc = jpeg_image.info['icc_profile']
+
+    assert_equal(icc, expected_icc)
+
+
+def test_write_icc_metadata():
+    file_path = "Tests/images/flower2.jpg"
+    image = Image.open(file_path)
+    expected_icc_profile = image.info['icc_profile']
+
+    buffer = StringIO()
+
+    image.save(buffer, "webp", icc_profile=expected_icc_profile)
+
+    buffer.seek(0)
+    webp_image = Image.open(buffer)
+
+    webp_icc_profile = webp_image.info.get('icc_profile', None)
+    assert_true(webp_icc_profile)
+    assert_equal(webp_icc_profile, expected_icc_profile)

_webp.c

@@ -5,6 +5,9 @@
 #include <webp/decode.h>
 #include <webp/types.h>
 
+#ifdef HAVE_WEBPMUX
+#include <webp/mux.h>
+#endif
 
 PyObject* WebPEncode_wrapper(PyObject* self, PyObject* args)
 {
@@ -12,12 +15,18 @@ PyObject* WebPEncode_wrapper(PyObject* self, PyObject* args)
     int height;
     float quality_factor;
     uint8_t *rgb;
+    uint8_t *icc_bytes;
+    uint8_t *exif_bytes;
     uint8_t *output;
     char *mode;
     Py_ssize_t size;
+    Py_ssize_t icc_size;
+    Py_ssize_t exif_size;
     size_t ret_size;
 
-    if (!PyArg_ParseTuple(args, "s#nifs",(char**)&rgb, &size, &width, &height, &quality_factor, &mode)) {
+    if (!PyArg_ParseTuple(args, "s#nifss#s#",
+                (char**)&rgb, &size, &width, &height, &quality_factor, &mode,
+                &icc_bytes, &icc_size, &exif_bytes, &exif_size)) {
         Py_RETURN_NONE;
     }
 
@@ -35,9 +44,42 @@ PyObject* WebPEncode_wrapper(PyObject* self, PyObject* args)
 		Py_RETURN_NONE;
 	}
 
+#ifdef HAVE_WEBPMUX
+    WebPData output_data = {0};
+    WebPData image = { output, ret_size };
+
+    int copy_data = 0;  // value 1 indicates given data WILL be copied to the mux
+                        // and value 0 indicates data will NOT be copied.
+
+    WebPMux* mux = WebPMuxNew();
+    WebPMuxSetImage(mux, &image, copy_data);
+
+    if (icc_size > 0) {
+        WebPData icc_profile = { icc_bytes, icc_size };
+        WebPMuxSetChunk(mux, "ICCP", &icc_profile, copy_data);
+    }
+
+    if (exif_size > 0) {
+        WebPData exif = { exif_bytes, exif_size };
+        WebPMuxSetChunk(mux, "EXIF", &exif, copy_data);
+    }
+
+    WebPMuxAssemble(mux, &output_data);
+    WebPMuxDelete(mux);
+
+    output = (uint8_t*)output_data.bytes;
+    ret_size = output_data.size;
+#endif
+
     if (ret_size > 0) {
         PyObject *ret = PyBytes_FromStringAndSize((char*)output, ret_size);
+
+#ifdef HAVE_WEBPMUX
+        WebPDataClear(&output_data);
+#else
         free(output);
+#endif
+
         return ret;
     }
     Py_RETURN_NONE;
@@ -49,7 +91,7 @@ PyObject* WebPDecode_wrapper(PyObject* self, PyObject* args)
     PyBytesObject *webp_string;
     uint8_t *webp;
     Py_ssize_t size;
-    PyObject *ret, *bytes, *pymode;
+    PyObject *ret, *bytes, *pymode, *icc_profile = Py_None, *exif = Py_None;
     WebPDecoderConfig config;
     VP8StatusCode vp8_status_code = VP8_STATUS_OK;
     char* mode = "RGB";
@@ -72,7 +114,35 @@ PyObject* WebPDecode_wrapper(PyObject* self, PyObject* args)
             config.output.colorspace = MODE_RGBA;
             mode = "RGBA";
         }
+
+#ifdef HAVE_WEBPMUX
+        int copy_data = 0;
+        WebPData data = { webp, size };
+        WebPMuxFrameInfo image;
+
+        WebPMux* mux = WebPMuxCreate(&data, copy_data);
+        WebPMuxGetFrame(mux, 1, &image);
+        webp = (uint8_t*)image.bitstream.bytes;
+        size = image.bitstream.size;
+#endif
+
         vp8_status_code = WebPDecode(webp, size, &config);
+
+#ifdef HAVE_WEBPMUX
+        WebPData icc_profile_data = {0};
+        WebPMuxGetChunk(mux, "ICCP", &icc_profile_data);
+        if (icc_profile_data.size > 0) {
+            icc_profile = PyBytes_FromStringAndSize((const char*)icc_profile_data.bytes, icc_profile_data.size);
+        }
+
+        WebPData exif_data = {0};
+        WebPMuxGetChunk(mux, "EXIF", &exif_data);
+        if (exif_data.size > 0) {
+            exif = PyBytes_FromStringAndSize((const char*)exif_data.bytes, exif_data.size);
+        }
+
+        WebPMuxDelete(mux);
+#endif
     }
 
     if (vp8_status_code != VP8_STATUS_OK) {
@@ -95,8 +165,8 @@ PyObject* WebPDecode_wrapper(PyObject* self, PyObject* args)
 #else
     pymode = PyString_FromString(mode);
 #endif
-    ret = Py_BuildValue("SiiS", bytes, config.output.width,
-                        config.output.height, pymode);
+    ret = Py_BuildValue("SiiSSS", bytes, config.output.width,
+                        config.output.height, pymode, icc_profile, exif);
     WebPFreeDecBuffer(&config.output);
     return ret;
 }
@@ -124,6 +194,14 @@ static PyMethodDef webpMethods[] =
     {NULL, NULL}
 };
 
+void addMuxFlagToModule(PyObject* m) {
+#ifdef HAVE_WEBPMUX
+    PyModule_AddObject(m, "HAVE_WEBPMUX", Py_True);
+#else
+    PyModule_AddObject(m, "HAVE_WEBPMUX", Py_False);
+#endif
+}
+
 
 #if PY_VERSION_HEX >= 0x03000000
 PyMODINIT_FUNC
@@ -139,12 +217,14 @@ PyInit__webp(void) {
     };
 
     m = PyModule_Create(&module_def);
+    addMuxFlagToModule(m);
     return m;
 }
 #else
 PyMODINIT_FUNC
 init_webp(void)
 {
-    Py_InitModule("_webp", webpMethods);
+    PyObject* m = Py_InitModule("_webp", webpMethods);
+    addMuxFlagToModule(m);
 }
 #endif

setup.py

@@ -86,7 +86,7 @@ LCMS_ROOT = None
 class pil_build_ext(build_ext):
 
     class feature:
-        zlib = jpeg = tiff = freetype = tcl = tk = lcms = webp = None
+        zlib = jpeg = tiff = freetype = tcl = tk = lcms = webp = webpmux = None
         required = []
 
         def require(self, feat):
@@ -329,6 +329,12 @@ class pil_build_ext(build_ext):
                 if _find_library_file(self, "webp"): # in googles precompiled zip it is call "libwebp"
                     feature.webp = "webp"
 
+        if feature.want('webpmux'):
+            if (_find_include_file(self, "webp/mux.h") and
+                    _find_include_file(self, "webp/demux.h")):
+                if _find_library_file(self, "webpmux") and _find_library_file(self, "webpdemux"):
+                    feature.webpmux = "webpmux"
+
         for f in feature:
             if not getattr(feature, f) and feature.require(f):
                 raise ValueError(
@@ -386,8 +392,16 @@ class pil_build_ext(build_ext):
                 "PIL._imagingcms", ["_imagingcms.c"], libraries=["lcms"] + extra))
 
         if os.path.isfile("_webp.c") and feature.webp:
+            libs = ["webp"]
+            defs = []
+
+            if feature.webpmux:
+                defs.append(("HAVE_WEBPMUX", None))
+                libs.append("webpmux")
+                libs.append("webpdemux")
+
             exts.append(Extension(
-                "PIL._webp", ["_webp.c"], libraries=["webp"]))
+                "PIL._webp", ["_webp.c"], libraries=libs, define_macros=defs))
 
         if sys.platform == "darwin":
             # locate Tcl/Tk frameworks
@@ -452,7 +466,8 @@ class pil_build_ext(build_ext):
             (feature.tiff, "TIFF G3/G4 (experimental)"),
             (feature.freetype, "FREETYPE2"),
             (feature.lcms, "LITTLECMS"),
-            (feature.webp, "WEBP"), ]
+            (feature.webp, "WEBP"),
+            (feature.webpmux, "WEBPMUX"), ]
 
         all = 1
         for option in options: