Support aspectwithbg style

README.md

@@ -87,15 +87,17 @@ Resized images by specifying `width` and `height`. There are three resizing styl
 
   * `aspectfill`: Default. The resulting image will be exactly the specified size, and may be cropped.
   * `aspectfit`: Scales the image so that it will not have to be cropped.
+  * `aspectwithbg`: Scales the image and fill the rest by background color.
   * `fill`: Squishes or stretches the image so that it fills exactly the specified size.
 
 ```js
 fs.writeFileSync('after_resize.jpg', imagemagick.convert({
 	srcData: fs.readFileSync('before_resize.jpg'),
 	width: 100,
 	height: 100,
-	resizeStyle: 'aspectfill', // is the default, or 'aspectfit' or 'fill'
-	gravity: 'Center' // optional: position crop area when using 'aspectfill'
+	resizeStyle: 'aspectfill', // is the default, or 'aspectfit', 'aspectwithbg' or 'fill'
+	gravity: 'Center', // optional: position crop area when using 'aspectfill'
+	background: '#4d4d4d' // optional: background color when using 'aspectwithbg'
 }));
 ```
 
@@ -105,9 +107,9 @@ Original:
 
 Resized:
 
-aspectfill | aspectfit | fill
-:---: | :---: | :---:
-![alt text](http://elad.github.io/node-imagemagick-native/examples/resize_aspectfill.jpg 'aspectfill') | ![alt text](http://elad.github.io/node-imagemagick-native/examples/resize_aspectfit.jpg 'aspectfit') | ![alt text](http://elad.github.io/node-imagemagick-native/examples/resize_fill.jpg 'fill')
+aspectfill | aspectfit | aspectwithbg | fill
+:---: | :---: | :---: | :---:
+![alt text](http://elad.github.io/node-imagemagick-native/examples/resize_aspectfill.jpg 'aspectfill') | ![alt text](http://elad.github.io/node-imagemagick-native/examples/resize_aspectfit.jpg 'aspectfit') | ![alt text](http://horiuchi.github.io/node-imagemagick-native/examples/resize_aspectwithbg.jpg 'aspectwithbg') | ![alt text](http://elad.github.io/node-imagemagick-native/examples/resize_fill.jpg 'fill')
 
 *Image courtesy of [Christoph](https://www.flickr.com/photos/scheinwelten/381994831).*
 
@@ -158,13 +160,15 @@ The `options` argument can have following values:
         width:          optional. px.
         height:         optional. px.
         density         optional. Integer dpi value to convert
-        resizeStyle:    optional. default: 'aspectfill'. can be 'aspectfit', 'fill'
-                        aspectfill: keep aspect ratio, get the exact provided size.
-                        aspectfit:  keep aspect ratio, get maximum image that fits inside provided size
-                        fill:       forget aspect ratio, get the exact provided size
+        resizeStyle:    optional. default: 'aspectfill'. can be 'aspectfit', 'aspectwithbg', 'fill'
+                        aspectfill:   keep aspect ratio, get the exact provided size.
+                        aspectfit:    keep aspect ratio, get maximum image that fits inside provided size
+                        aspectwithbg: keep aspect ratio, get the exact proviede size and no cropped.
+                        fill:         forget aspect ratio, get the exact provided size
         gravity:        optional. default: 'Center'. used to position the crop area when resizeStyle is 'aspectfill'
                                   can be 'NorthWest', 'North', 'NorthEast', 'West',
                                   'Center', 'East', 'SouthWest', 'South', 'SouthEast', 'None'
+        background:     optional. default: 'Transpearental'. used to background color when resizeStle is 'aspectwithbg'
         format:         optional. output format, ex: 'JPEG'. see below for candidates
         filter:         optional. resize filter. ex: 'Lagrange', 'Lanczos'.  see below for candidates
         blur:           optional. ex: 0.8

src/imagemagick.cc

@@ -87,6 +87,7 @@ struct convert_im_ctx : im_ctx_base {
     std::string format;
     std::string filter;
     std::string blur;
+    std::string background;
     unsigned int quality;
     int rotate;
     int density;
@@ -179,6 +180,25 @@ void DoConvert(uv_work_t* req) {
 
     Magick::Image image;
 
+    if ( ! context->background.empty() ) {
+        const char* background = context->background.c_str();
+        try {
+            Magick::Color bg(background);
+            image.backgroundColor(bg);
+            if (debug) printf( "set background: %s\n", background );
+        }
+        catch (std::exception& err) {
+            std::string message = "image.backgroundColor failed with error: ";
+            message            += err.what();
+            context->error = message;
+            return;
+        }
+        catch (...) {
+            context->error = std::string("unhandled error");
+            return;
+        }
+    }
+
     if ( !ReadImageMagick(&image, srcBlob, context->srcFormat, context) )
         return;
 
@@ -382,6 +402,58 @@ void DoConvert(uv_work_t* req) {
                 return;
             }
         }
+        else if ( strcmp ( resizeStyle, "aspectwithbg" ) == 0 ) {
+            // keep aspect ratio, get the maximum image which fits inside specified size
+            char geometryString[ 32 ];
+            sprintf( geometryString, "%dx%d", width, height );
+            if (debug) printf( "resize to: %s\n", geometryString );
+
+            Magick::Image compositeImage(image);
+            try {
+                compositeImage.zoom( geometryString );
+            }
+            catch (std::exception& err) {
+                std::string message = "image.resize failed with error: ";
+                message            += err.what();
+                context->error = message;
+                return;
+            }
+            catch (...) {
+                context->error = std::string("unhandled error");
+                return;
+            }
+
+            sprintf( geometryString, "%dx%d!", width, height );
+            if (debug) printf( "set background to: %s\n", geometryString );
+            try {
+                image.erase();
+                image.zoom( geometryString );
+            }
+            catch (std::exception& err) {
+                std::string message = "image.initialize failed with error: ";
+                message            += err.what();
+                context->error = message;
+                return;
+            }
+            catch (...) {
+                context->error = std::string("unhandled error");
+                return;
+            }
+
+            try {
+                image.composite(compositeImage, Magick::CenterGravity, Magick::OverCompositeOp);
+            }
+            catch (std::exception& err) {
+                std::string message = "image.composite failed with error: ";
+                message            += err.what();
+                context->error = message;
+                return;
+            }
+            catch (...) {
+                context->error = std::string("unhandled error");
+                return;
+            }
+        }
         else {
             context->error = std::string("resizeStyle not supported");
             return;
@@ -556,6 +628,10 @@ NAN_METHOD(Convert) {
     context->filter = !filterValue->IsUndefined() ?
         *String::Utf8Value(filterValue) : "";
 
+    Local<Value> backgroundValue = obj->Get( Nan::New<String>("background").ToLocalChecked() );
+    context->background = !backgroundValue->IsUndefined() ?
+        *String::Utf8Value(backgroundValue) : "";
+
     uv_work_t* req = new uv_work_t();
     req->data = context;
     if(!isSync) {

test/benchmark.js

@@ -19,7 +19,7 @@ function resize (callback) {
     }, function (err,stdout,stderr) {
         assert( stdout.length > 0 );
         // console.log( "im length: "+stdout.length );
-        // require('fs').writeFileSync( "./test/out.fork.jpg", stdout, 'binary' );
+        // require('fs').writeFileSync( "out.fork.jpg", stdout, 'binary' );
         callback();
     });
 }
@@ -38,7 +38,7 @@ function resize_native (callback) {
     });
     assert( stdout.length > 0 );
     // console.log( "im_native length: "+stdout.length );
-    // require('fs').writeFileSync( "./test/out.native.jpg", stdout, 'binary' );
+    // require('fs').writeFileSync( "out.native.jpg", stdout, 'binary' );
     callback();
 }
 

test/leak.js

@@ -9,7 +9,7 @@ memwatch.on( 'leak', function( info ) {
 memwatch.on('stats', function(stats) {
     console.log( "stats: ", stats );
 });
-var srcData = require('fs').readFileSync( "./test/test.jpg" );
+var srcData = require('fs').readFileSync( "test.jpg" );
 
 var hd = new memwatch.HeapDiff();
 

test/test.js

@@ -226,6 +226,44 @@ test( 'convert jpg -> jpg aspectfit', function (t) {
     t.end();
 });
 
+test( 'convert png -> png aspectwithbg', function (t) {
+    var buffer = imagemagick.convert({
+        srcData: require('fs').readFileSync( "test.png" ), // 58x66
+        width: 100,
+        height: 100,
+        resizeStyle: 'aspectwithbg',
+        background: '#4d4d4d',
+        quality: 80,
+        format: 'PNG',
+        debug: debug
+    });
+    t.equal( Buffer.isBuffer(buffer), true, 'buffer is Buffer' );
+    var info = imagemagick.identify({srcData: buffer });
+    t.equal( info.width, 100 );
+    t.equal( info.height, 100 );
+    saveToFileIfDebug( buffer, "out.png-aspectwithbg.png" );
+    t.end();
+});
+
+test( 'convert png.wide -> png.wide aspectwithbg', function (t) {
+    var buffer = imagemagick.convert({
+        srcData: require('fs').readFileSync( "test.wide.png" ), // 66x58
+        width: 100,
+        height: 100,
+        resizeStyle: 'aspectwithbg',
+        background: '#4d4d4d',
+        quality: 80,
+        format: 'PNG',
+        debug: debug
+    });
+    t.equal( Buffer.isBuffer(buffer), true, 'buffer is Buffer' );
+    var info = imagemagick.identify({srcData: buffer });
+    t.equal( info.width, 100 );
+    t.equal( info.height, 100 );
+    saveToFileIfDebug( buffer, "out.wide.png-aspectwithbg.png" );
+    t.end();
+});
+
 test( 'convert broken png', function (t) {
     var srcData = require('fs').readFileSync( "broken.png" )
     , buffer;