Sends width and height as another parameter to the callback. Fixes issue #67

README.md

@@ -79,51 +79,62 @@ var sharp = require('sharp');
 ```
 
 ```javascript
-sharp('input.jpg').resize(300, 200).toFile('output.jpg', function(err) {
+sharp('input.jpg').resize(300, 200).toFile('output.jpg', function(err, info) {
   if (err) {
     throw err;
   }
   // output.jpg is a 300 pixels wide and 200 pixels high image
   // containing a scaled and cropped version of input.jpg
+  
+  // info.width and info.height contain the final pixel dimensions of the resized image
+  // in this case they are the same as the input
 });
 ```
 
 ```javascript
-sharp('input.jpg').rotate().resize(null, 200).progressive().toBuffer(function(err, outputBuffer) {
+sharp('input.jpg').rotate().resize(null, 200).progressive().toBuffer(function(err, outputBuffer, info) {
   if (err) {
     throw err;
   }
   // outputBuffer contains 200px high progressive JPEG image data, auto-rotated using EXIF Orientation tag
+  // info.width and info.height contain the final pixel dimensions of the resized image
 });
 ```
 
 ```javascript
-sharp('input.png').rotate(180).resize(300).sharpen().quality(90).webp().then(function(outputBuffer) {
+sharp('input.png').rotate(180).resize(300).sharpen().quality(90).webp().then(function(outputBuffer, info) {
   // outputBuffer contains 300px wide, upside down, sharpened, 90% quality WebP image data
+  // info.width and info.height contain the final pixel dimensions of the resized image
 });
 ```
 
 ```javascript
-sharp(inputBuffer).resize(200, 300).bicubicInterpolation().embedWhite().toFile('output.tiff').then(function() {
+sharp(inputBuffer).resize(200, 300).bicubicInterpolation().embedWhite().toFile('output.tiff').then(function(info) {
   // output.tiff is a 200 pixels wide and 300 pixels high image containing a bicubic scaled
   // version, embedded on a white canvas, of the image data in buffer
+  
+  // info.width and info.height contain the final pixel dimensions of the resized image
 });
 ```
 
 ```javascript
-sharp('input.gif').resize(200, 300).embedBlack().webp(function(err, outputBuffer) {
+sharp('input.gif').resize(200, 300).embedBlack().webp(function(err, outputBuffer, info) {
   if (err) {
     throw err;
   }
   // outputBuffer contains WebP image data of a 200 pixels wide and 300 pixels high
   // containing a scaled version, embedded on a black canvas, of input.gif
+  
+  // info.width and info.height contain the final pixel dimensions of the resized image
 });
 ```
 
 ```javascript
-sharp(inputBuffer).resize(200, 200).max().jpeg().then(function(outputBuffer) {
+sharp(inputBuffer).resize(200, 200).max().jpeg().then(function(outputBuffer, info) {
   // outputBuffer contains JPEG image data no wider than 200 pixels and no higher
   // than 200 pixels regardless of the inputBuffer image dimensions
+  
+  // info.width and info.height contain the final pixel dimensions of the resized image
 });
 ```
 
@@ -216,7 +227,7 @@ An advanced setting that switches the libvips access method to `VIPS_ACCESS_SEQU
 
 `filename` is a String containing the filename to write the image data to. The format is inferred from the extension, with JPEG, PNG, WebP and TIFF supported.
 
-`callback`, if present, is called with a single argument `(err)` containing an error message, if any.
+`callback`, if present, is called with two arguments `(err, info)` where `err` contains an error message, if any, and `info` contains the final resized image dimensions in its `width` and `height` properties.
 
 A Promises/A+ promise is returned when `callback` is not provided.
 
@@ -224,7 +235,7 @@ A Promises/A+ promise is returned when `callback` is not provided.
 
 Write image data to a Buffer, the format of which will match the input image. JPEG, PNG and WebP are supported.
 
-`callback`, if present, gets two arguments `(err, buffer)` where `err` is an error message, if any, and `buffer` is the resultant image data.
+`callback`, if present, gets three arguments `(err, buffer, info)` where `err` is an error message, if any, `buffer` is the resultant image data, and `info` contains the final resized image dimensions in its `width` and `height` properties.
 
 A Promises/A+ promise is returned when `callback` is not provided.
 
@@ -232,7 +243,7 @@ A Promises/A+ promise is returned when `callback` is not provided.
 
 Write JPEG image data to a Buffer.
 
-`callback`, if present, gets two arguments `(err, buffer)` where `err` is an error message, if any, and `buffer` is the resultant JPEG image data.
+`callback`, if present, gets three arguments `(err, buffer, info)` where `err` is an error message, if any, `buffer` is resultant JPEG image data, and `info` contains the final resized image dimensions in its `width` and `height` properties.
 
 A Promises/A+ promise is returned when `callback` is not provided.
 
@@ -240,7 +251,7 @@ A Promises/A+ promise is returned when `callback` is not provided.
 
 Write PNG image data to a Buffer.
 
-`callback`, if present, gets two arguments `(err, buffer)` where `err` is an error message, if any, and `buffer` is the resultant PNG image data.
+`callback`, if present, gets three arguments `(err, buffer, info)` where `err` is an error message, if any, `buffer` is resultant PNG image data, and `info` contains the final resized image dimensions in its `width` and `height` properties.
 
 A Promises/A+ promise is returned when `callback` is not provided.
 
@@ -248,7 +259,7 @@ A Promises/A+ promise is returned when `callback` is not provided.
 
 Write WebP image data to a Buffer.
 
-`callback`, if present, gets two arguments `(err, buffer)` where `err` is an error message, if any, and `buffer` is the resultant WebP image data.
+`callback`, if present, gets three arguments `(err, buffer, info)` where `err` is an error message, if any, `buffer` is resultant WebP image data, and `info` contains the final resized image dimensions in its `width` and `height` properties.
 
 A Promises/A+ promise is returned when `callback` is not provided.
 

index.js

@@ -222,11 +222,11 @@ Sharp.prototype._sharp = function(output, callback) {
     // I like promises
     var options = this.options;
     return new Promise(function(resolve, reject) {
-      sharp.resize(options, output, function(err, data) {
+      sharp.resize(options, output, function(err, data, info) {
         if (err) {
           reject(err);
         } else {
-          resolve(data);
+          resolve(data, info);
         }
       });
     });

package.json

@@ -4,7 +4,8 @@
   "author": "Lovell Fuller <npm@lovell.info>",
   "contributors": [
     "Pierre Inglebert <pierre.inglebert@gmail.com>",
-    "Jonathan Ong <jonathanrichardong@gmail.com>"
+    "Jonathan Ong <jonathanrichardong@gmail.com>",
+    "Chanon Sajjamanochai <chanon.s@gmail.com>"
   ],
   "description": "High performance Node.js module to resize JPEG, PNG and WebP images using the libvips library",
   "scripts": {

src/sharp.cc

@@ -431,17 +431,28 @@ class ResizeWorker : public NanAsyncWorker {
   void HandleOKCallback () {
     NanScope();
 
-    Handle<Value> argv[2] = { NanNull(), NanNull() };
+    Handle<Value> argv[3] = { NanNull(), NanNull(),  NanNull() };
     if (!baton->err.empty()) {
       // Error
       argv[0] = NanNew<String>(baton->err.data(), baton->err.size());
-    } else if (baton->buffer_out_len > 0) {
+    } else {
+      // Info Object
+      Local<Object> info = NanNew<Object>();
+      info->Set(NanNew<String>("width"), NanNew<Number>(baton->width));
+      info->Set(NanNew<String>("height"), NanNew<Number>(baton->height));
+
+      if (baton->buffer_out_len > 0) {
         // Buffer
         argv[1] = NanNewBufferHandle((char *)baton->buffer_out, baton->buffer_out_len);
         g_free(baton->buffer_out);
+        argv[2] = info;
+      } else {
+        // File
+        argv[1] = info;
+      }
     }
     delete baton;
-    callback->Call(2, argv);
+    callback->Call(3, argv);
     // Decrement queue length
     g_atomic_int_dec_and_test(&queue_length);
   }

tests/unit.js

@@ -21,8 +21,10 @@ var inputJpgWithExif = path.join(fixturesPath, "Landscape_8.jpg"); // https://gi
 async.series([
   // Resize with exact crop
   function(done) {
-    sharp(inputJpg).resize(320, 240).toFile(outputJpg, function(err) {
+    sharp(inputJpg).resize(320, 240).toFile(outputJpg, function(err, info) {
       if (err) throw err;
+      assert.strictEqual(320, info.width);
+      assert.strictEqual(240, info.height);
       imagemagick.identify(outputJpg, function(err, features) {
         if (err) throw err;
         assert.strictEqual(320, features.width);
@@ -33,8 +35,10 @@ async.series([
   },
   // Resize to fixed width
   function(done) {
-    sharp(inputJpg).resize(320).toFile(outputJpg, function(err) {
+    sharp(inputJpg).resize(320).toFile(outputJpg, function(err, info) {
       if (err) throw err;
+      assert.strictEqual(320, info.width);
+      assert.strictEqual(261, info.height);
       imagemagick.identify(outputJpg, function(err, features) {
         if (err) throw err;
         assert.strictEqual(320, features.width);
@@ -45,8 +49,10 @@ async.series([
   },
   // Resize to fixed height
   function(done) {
-    sharp(inputJpg).resize(null, 320).toFile(outputJpg, function(err) {
+    sharp(inputJpg).resize(null, 320).toFile(outputJpg, function(err, info) {
       if (err) throw err;
+      assert.strictEqual(391, info.width);
+      assert.strictEqual(320, info.height);
       imagemagick.identify(outputJpg, function(err, features) {
         if (err) throw err;
         assert.strictEqual(391, features.width);
@@ -69,8 +75,10 @@ async.series([
   },
   // Upscale
   function(done) {
-    sharp(inputJpg).resize(3000).toFile(outputJpg, function(err) {
+    sharp(inputJpg).resize(3000).toFile(outputJpg, function(err, info) {
       if (err) throw err;
+      assert.strictEqual(3000, info.width);
+      assert.strictEqual(2449, info.height);
       imagemagick.identify(outputJpg, function(err, features) {
         if (err) throw err;
         assert.strictEqual(3000, features.width);
@@ -118,8 +126,10 @@ async.series([
   },
   // Resize to max width or height considering ratio (landscape)
   function(done) {
-    sharp(inputJpg).resize(320, 320).max().toFile(outputJpg, function(err) {
+    sharp(inputJpg).resize(320, 320).max().toFile(outputJpg, function(err, info) {
       if (err) throw err;
+      assert.strictEqual(320, info.width);
+      assert.strictEqual(261, info.height);
       imagemagick.identify(outputJpg, function(err, features) {
         if (err) throw err;
         assert.strictEqual(320, features.width);
@@ -130,8 +140,10 @@ async.series([
   },
   // Resize to max width or height considering ratio (portrait)
   function(done) {
-    sharp(inputTiff).resize(320, 320).max().toFile(outputJpg, function(err) {
+    sharp(inputTiff).resize(320, 320).max().toFile(outputJpg, function(err, info) {
       if (err) throw err;
+      assert.strictEqual(243, info.width);
+      assert.strictEqual(320, info.height);
       imagemagick.identify(outputJpg, function(err, features) {
         if (err) throw err;
         assert.strictEqual(243, features.width);
@@ -142,8 +154,10 @@ async.series([
   },
   // Attempt to resize to max but only provide one dimension, so should default to crop
   function(done) {
-    sharp(inputJpg).resize(320).max().toFile(outputJpg, function(err) {
+    sharp(inputJpg).resize(320).max().toFile(outputJpg, function(err, info) {
       if (err) throw err;
+      assert.strictEqual(320, info.width);
+      assert.strictEqual(261, info.height);
       imagemagick.identify(outputJpg, function(err, features) {
         if (err) throw err;
         assert.strictEqual(320, features.width);
@@ -161,8 +175,10 @@ async.series([
   },
   // Rotate by 90 degrees, respecting output input size
   function(done) {
-    sharp(inputJpg).rotate(90).resize(320, 240).toFile(outputJpg, function(err) {
+    sharp(inputJpg).rotate(90).resize(320, 240).toFile(outputJpg, function(err, info) {
       if (err) throw err;
+      assert.strictEqual(320, info.width);
+      assert.strictEqual(240, info.height);
       imagemagick.identify(outputJpg, function(err, features) {
         if (err) throw err;
         assert.strictEqual(320, features.width);
@@ -173,8 +189,10 @@ async.series([
   },
   // Input image has Orientation EXIF tag but do not rotate output
   function(done) {
-    sharp(inputJpgWithExif).resize(320).toFile(outputJpg, function(err) {
+    sharp(inputJpgWithExif).resize(320).toFile(outputJpg, function(err, info) {
       if (err) throw err;
+      assert.strictEqual(320, info.width);
+      assert.strictEqual(426, info.height);
       imagemagick.identify(outputJpg, function(err, features) {
         if (err) throw err;
         assert.strictEqual(320, features.width);
@@ -185,8 +203,10 @@ async.series([
   },
   // Input image has Orientation EXIF tag value of 8 (270 degrees), auto-rotate
   function(done) {
-    sharp(inputJpgWithExif).rotate().resize(320).toFile(outputJpg, function(err) {
+    sharp(inputJpgWithExif).rotate().resize(320).toFile(outputJpg, function(err, info) {
       if (err) throw err;
+      assert.strictEqual(320, info.width);
+      assert.strictEqual(240, info.height);
       imagemagick.identify(outputJpg, function(err, features) {
         if (err) throw err;
         assert.strictEqual(320, features.width);
@@ -197,8 +217,10 @@ async.series([
   },
   // Attempt to auto-rotate using image that has no EXIF
   function(done) {
-    sharp(inputJpg).rotate().resize(320).toFile(outputJpg, function(err) {
+    sharp(inputJpg).rotate().resize(320).toFile(outputJpg, function(err, info) {
       if (err) throw err;
+      assert.strictEqual(320, info.width);
+      assert.strictEqual(261, info.height);
       imagemagick.identify(outputJpg, function(err, features) {
         if (err) throw err;
         assert.strictEqual(320, features.width);
@@ -219,8 +241,10 @@ async.series([
   },
   // Do not enlarge the output if the input width is already less than the output width
   function(done) {
-    sharp(inputJpg).resize(2800).withoutEnlargement().toFile(outputJpg, function(err) {
+    sharp(inputJpg).resize(2800).withoutEnlargement().toFile(outputJpg, function(err, info) {
       if (err) throw err;
+      assert.strictEqual(2725, info.width);
+      assert.strictEqual(2225, info.height);
       imagemagick.identify(outputJpg, function(err, features) {
         if (err) throw err;
         assert.strictEqual(2725, features.width);
@@ -231,8 +255,10 @@ async.series([
   },
   // Do not enlarge the output if the input height is already less than the output height
   function(done) {
-    sharp(inputJpg).resize(null, 2300).withoutEnlargement().toFile(outputJpg, function(err) {
+    sharp(inputJpg).resize(null, 2300).withoutEnlargement().toFile(outputJpg, function(err, info) {
       if (err) throw err;
+      assert.strictEqual(2725, info.width);
+      assert.strictEqual(2225, info.height);
       imagemagick.identify(outputJpg, function(err, features) {
         if (err) throw err;
         assert.strictEqual(2725, features.width);
@@ -243,7 +269,9 @@ async.series([
   },
   // Promises/A+
   function(done) {
-    sharp(inputJpg).resize(320, 240).toFile(outputJpg).then(function() {
+    sharp(inputJpg).resize(320, 240).toFile(outputJpg).then(function(info) {
+      assert.strictEqual(320, info.width);
+      assert.strictEqual(240, info.height);      
       imagemagick.identify(outputJpg, function(err, features) {
         assert.strictEqual(320, features.width);
         assert.strictEqual(240, features.height);