Provide XMP as a string, as well as a Buffer, where possible

docs/src/content/docs/changelog.md

@@ -20,6 +20,8 @@ Requires libvips v8.17.0
 
 * Add support for RAW digital camera image input. Requires libvips compiled with libraw support.
 
+* Provide XMP metadata as a string, as well as a Buffer, where possible.
+
 * Add `pageHeight` option to `create` and `raw` input for animated images.
   [#3236](https://github.com/lovell/sharp/issues/3236)
 

lib/index.d.ts

@@ -1254,6 +1254,8 @@ declare namespace sharp {
         iptc?: Buffer | undefined;
         /** Buffer containing raw XMP data, if present */
         xmp?: Buffer | undefined;
+        /** String containing XMP data, if valid UTF-8 */
+        xmpAsString?: string | undefined;
         /** Buffer containing raw TIFFTAG_PHOTOSHOP data, if present */
         tifftagPhotoshop?: Buffer | undefined;
         /** The encoder used to compress an HEIF file, `av1` (AVIF) or `hevc` (HEIC) */

lib/input.js

@@ -605,6 +605,7 @@ function _isStreamInput () {
  * - `icc`: Buffer containing raw [ICC](https://www.npmjs.com/package/icc) profile data, if present
  * - `iptc`: Buffer containing raw IPTC data, if present
  * - `xmp`: Buffer containing raw XMP data, if present
+ * - `xmpAsString`: String containing XMP data, if valid UTF-8.
  * - `tifftagPhotoshop`: Buffer containing raw TIFFTAG_PHOTOSHOP data, if present
  * - `formatMagick`: String containing format for images loaded via *magick
  * - `comments`: Array of keyword/text pairs representing PNG text blocks, if present.

src/metadata.cc

@@ -262,6 +262,10 @@ class MetadataWorker : public Napi::AsyncWorker {
       }
       if (baton->xmpLength > 0) {
         info.Set("xmp", Napi::Buffer<char>::NewOrCopy(env, baton->xmp, baton->xmpLength, sharp::FreeCallback));
+        if (g_utf8_validate(static_cast<char const *>(baton->xmp), baton->xmpLength, nullptr)) {
+          info.Set("xmpAsString",
+            Napi::String::New(env, static_cast<char const *>(baton->xmp), baton->xmpLength));
+        }
       }
       if (baton->tifftagPhotoshopLength > 0) {
         info.Set("tifftagPhotoshop",

test/unit/metadata.js

@@ -82,6 +82,7 @@ describe('Image metadata', function () {
       assert.strictEqual(true, metadata.xmp instanceof Buffer);
       assert.strictEqual(12466, metadata.xmp.byteLength);
       assert.strictEqual(metadata.xmp.indexOf(Buffer.from('<?xpacket begin="')), 0);
+      assert(metadata.xmpAsString.startsWith('<?xpacket begin="" id="W5M0MpCehiHzreSzNTczkc9d"?>'));
       done();
     });
   });
@@ -106,6 +107,8 @@ describe('Image metadata', function () {
       assert.strictEqual(3248, metadata.autoOrient.height);
       assert.strictEqual('undefined', typeof metadata.exif);
       assert.strictEqual('undefined', typeof metadata.icc);
+      assert.strictEqual('undefined', typeof metadata.xmp);
+      assert.strictEqual('undefined', typeof metadata.xmpAsString);
       assert.strictEqual('inch', metadata.resolutionUnit);
       done();
     });