diff --git a/README.md b/README.md
index 0bf572d..d677669 100644
--- a/README.md
+++ b/README.md
@@ -65,7 +65,7 @@ Get size (width and height) from webp image:
     WebP.webp_size(File.open(filename, "rb").read)
      => [2000, 2353]
     
-### Encode png, jpg or tiff image to WebP image
+### Encode WebP image
 
 Encode png, jpg or tiff image to webp:
 
@@ -73,7 +73,7 @@ Encode png, jpg or tiff image to webp:
     out_filename = File.expand_path(File.join(File.dirname(__FILE__), "tmp/4.webp"))
     WebP.encode(filename, out_filename)
      
-Encode png, jpg or tiff image to webp (with options):
+Encode png, jpg or tiff image to webp with options:
 
     WebP.encode(filename, out_filename, quality: 50, resize_w: 100, resize_h: 200)
     WebP.encode(filename, out_filename, quality: 75, crop_x: 0, cropt_y: 0, crop_w: 100, crop_h: 100)
@@ -103,13 +103,34 @@ Possible encode options:
  * **crop\_x** (int), **crop\_y** (int), **crop\_w** (int), **crop\_h** (int) - crop picture with the given rectangle
  * **resize\_w** (int), **resize\_h** (int) - resize picture (after any cropping)
  
-### Decode WebP image to png image
+### Decode WebP image
 
-Decode webp image to png:
+Decode webp image (default format is png):
 
     filename = File.expand_path(File.join(File.dirname(__FILE__), "spec/factories/4.webp"))
     out_filename = File.expand_path(File.join(File.dirname(__FILE__), "tmp/4.png"))
     WebP.decode(filename, out_filename)
+    
+Decode webp image to pam, ppm or pgm format of image:
+
+    filename = File.expand_path(File.join(File.dirname(__FILE__), "spec/factories/4.webp"))
+    out_filename = File.expand_path(File.join(File.dirname(__FILE__), "tmp/4.png"))
+    WebP.decode(filename, out_filename, output_format: :pam)
+    WebP.decode(filename, out_filename, output_format: :ppm)
+    WebP.decode(filename, out_filename, output_format: :pgm)
+    
+Decode webp image with options:
+
+    WebP.encode(filename, out_filename, resize_w: 100, resize_h: 200)
+    WebP.encode(filename, out_filename, crop_x: 0, cropt_y: 0, crop_w: 100, crop_h: 100)
+    
+Possible decode options:
+
+ * **bypass\_filtering** (bool) - disable in-loop filtering
+ * **no\_fancy\_upsampling** (bool) - don't use the fancy YUV420 upscaler
+ * **use\_threads** (bool) - use multi-threading
+ * **crop\_x** (int), **crop\_y** (int), **crop\_w** (int), **crop\_h** (int) - crop picture with the given rectangle
+ * **resize\_w** (int), **resize\_h** (int) - resize picture (after any cropping)
 
 ## Contributing
 
diff --git a/ext/webp_ffi/util.c b/ext/webp_ffi/util.c
index e6aec8b..c42457e 100644
--- a/ext/webp_ffi/util.c
+++ b/ext/webp_ffi/util.c
@@ -280,6 +280,52 @@ static int UtilWritePPM(FILE* fout, const WebPDecBuffer* const buffer, int alpha
   return 1;
 }
 
+static int UtilWriteAlphaPlane(FILE* fout, const WebPDecBuffer* const buffer) {
+  const uint32_t width = buffer->width;
+  const uint32_t height = buffer->height;
+  const unsigned char* const a = buffer->u.YUVA.a;
+  const int a_stride = buffer->u.YUVA.a_stride;
+  uint32_t y;
+  assert(a != NULL);
+  fprintf(fout, "P5\n%d %d\n255\n", width, height);
+  for (y = 0; y < height; ++y) {
+    if (fwrite(a + y * a_stride, width, 1, fout) != 1) {
+      return 0;
+    }
+  }
+  return 1;
+}
+
+static int UtilWritePGM(FILE* fout, const WebPDecBuffer* const buffer) {
+  const int width = buffer->width;
+  const int height = buffer->height;
+  const WebPYUVABuffer* const yuv = &buffer->u.YUVA;
+  // Save a grayscale PGM file using the IMC4 layout
+  // (http://www.fourcc.org/yuv.php#IMC4). This is a very
+  // convenient format for viewing the samples, esp. for
+  // odd dimensions.
+  int ok = 1;
+  int y;
+  const int uv_width = (width + 1) / 2;
+  const int uv_height = (height + 1) / 2;
+  const int out_stride = (width + 1) & ~1;
+  const int a_height = yuv->a ? height : 0;
+  fprintf(fout, "P5\n%d %d\n255\n", out_stride, height + uv_height + a_height);
+  for (y = 0; ok && y < height; ++y) {
+    ok &= (fwrite(yuv->y + y * yuv->y_stride, width, 1, fout) == 1);
+    if (width & 1) fputc(0, fout);    // padding byte
+  }
+  for (y = 0; ok && y < uv_height; ++y) {
+    ok &= (fwrite(yuv->u + y * yuv->u_stride, uv_width, 1, fout) == 1);
+    ok &= (fwrite(yuv->v + y * yuv->v_stride, uv_width, 1, fout) == 1);
+  }
+  for (y = 0; ok && y < a_height; ++y) {
+    ok &= (fwrite(yuv->a + y * yuv->a_stride, width, 1, fout) == 1);
+    if (width & 1) fputc(0, fout);    // padding byte
+  }
+  return ok;
+}
+
 static int UtilReadTIFF(const char* const filename,
                     WebPPicture* const pic, int keep_alpha) {
   TIFF* const tif = TIFFOpen(filename, "r");
@@ -397,14 +443,12 @@ int UtilSaveOutput(const WebPDecBuffer* const buffer,
     ok &= UtilWritePPM(fout, buffer, 1);
   } else if (format == PPM) {
     ok &= UtilWritePPM(fout, buffer, 0);
-  }
-  /*
   } else if (format == PGM) {
-    ok &= WritePGM(fout, buffer);
+    ok &= UtilWritePGM(fout, buffer);
   } else if (format == ALPHA_PLANE_ONLY) {
-    ok &= WriteAlphaPlane(fout, buffer);
+    ok &= UtilWriteAlphaPlane(fout, buffer);
   }
-  */
+
   if (fout) {
     fclose(fout);
   }
diff --git a/ext/webp_ffi/webp_ffi.c b/ext/webp_ffi/webp_ffi.c
index d6a3705..2dc686e 100644
--- a/ext/webp_ffi/webp_ffi.c
+++ b/ext/webp_ffi/webp_ffi.c
@@ -195,13 +195,34 @@ int webp_decode(const char *in_file, const char *out_file, const FfiWebpDecodeCo
   OutputFileFormat format = PNG;
 
   if (!WebPInitDecoderConfig(&config)) {
-    fprintf(stderr, "Library version mismatch!\n");
+    //fprintf(stderr, "Library version mismatch!\n");
     return 1;
   }
   
   if (decode_config->output_format != format){
     format = decode_config->output_format;
   }
+  if (decode_config->no_fancy_upsampling > 0){
+    config.options.no_fancy_upsampling = 1;
+  }
+  if (decode_config->bypass_filtering > 0){
+    config.options.bypass_filtering = 1;
+  }
+  if (decode_config->use_threads > 0){
+    config.options.use_threads = 1;
+  }
+  if ((decode_config->crop_w | decode_config->crop_h) > 0){
+    config.options.use_cropping = 1;
+    config.options.crop_left   = decode_config->crop_x;
+    config.options.crop_top    = decode_config->crop_y;
+    config.options.crop_width  = decode_config->crop_w;
+    config.options.crop_height = decode_config->crop_h;
+  }
+  if ((decode_config->resize_w | decode_config->resize_h) > 0){
+    config.options.use_scaling = 1;
+    config.options.scaled_width  = decode_config->resize_w;
+    config.options.scaled_height = decode_config->resize_h;
+  }
   
   VP8StatusCode status = VP8_STATUS_OK;
   size_t data_size = 0;
@@ -211,7 +232,7 @@ int webp_decode(const char *in_file, const char *out_file, const FfiWebpDecodeCo
   
   status = WebPGetFeatures(data, data_size, bitstream);
   if (status != VP8_STATUS_OK) {
-    fprintf(stderr, "This is invalid webp image!\n");
+    //fprintf(stderr, "This is invalid webp image!\n");
     return_value = 2;
     goto Error;
   }
@@ -239,7 +260,7 @@ int webp_decode(const char *in_file, const char *out_file, const FfiWebpDecodeCo
   status = WebPDecode(data, data_size, &config);
   
   if (status != VP8_STATUS_OK) {
-    fprintf(stderr, "Decoding of %s failed.\n", in_file);
+    //fprintf(stderr, "Decoding of %s failed.\n", in_file);
     return_value = 4;
     goto Error;
   }
diff --git a/lib/webp/error.rb b/lib/webp/error.rb
index a19b47d..992465c 100644
--- a/lib/webp/error.rb
+++ b/lib/webp/error.rb
@@ -10,7 +10,10 @@ module WebP
     "Cannot encode picture as WebP"]
     
   DECODER_ERRORS = [
-    ""]
+    "Version mismatch", 
+    "Invalid webp image", 
+    "Invalid output format",
+    "Decoding failed"]
   
   class InvalidImageFormatError < StandardError; end
   class EncoderError < StandardError; end
diff --git a/lib/webp/options.rb b/lib/webp/options.rb
index abed806..3ca17fa 100644
--- a/lib/webp/options.rb
+++ b/lib/webp/options.rb
@@ -31,6 +31,13 @@ def decode_pointer
       if @user_options[:output_format] && [:png, :pam, :ppm, :pgm, :alpha_plane_only].include?(@user_options[:output_format])
         options_struct[:output_format] = C::OutputFileFormat[@user_options[:output_format]]
       end
+      [:bypass_filtering, :no_fancy_upsampling, :use_threads].each do |key|
+        options_struct[key] = 1 if @user_options[key] && true == @user_options[key]
+      end
+      [:crop_x, :crop_y, :crop_w, 
+        :crop_h, :resize_w, :resize_h].each do |key|
+          options_struct[key] = @user_options[key] if @user_options[key]
+      end
       options_pointer
     end
     
@@ -38,13 +45,19 @@ def decode_pointer
 
     def encode_default(options_struct)
       options_struct[:quality] = 100
-      options_struct[:crop_x] = options_struct[:crop_y] = 0
-      options_struct[:crop_w] = options_struct[:crop_h] = 0
-      options_struct[:resize_w] = options_struct[:resize_h] = 0
+      similar_default(options_struct)
     end
     
     def decode_default(options_struct)
+      # default format is png
       options_struct[:output_format] = C::OutputFileFormat[:png]
+      similar_default(options_struct)
+    end
+    
+    def similar_default(options_struct)
+      options_struct[:crop_x] = options_struct[:crop_y] = 0
+      options_struct[:crop_w] = options_struct[:crop_h] = 0
+      options_struct[:resize_w] = options_struct[:resize_h] = 0
     end
 
   end
diff --git a/spec/factories/5.jpg b/spec/factories/3.jpg
similarity index 100%
rename from spec/factories/5.jpg
rename to spec/factories/3.jpg
diff --git a/spec/factories/3.png b/spec/factories/3.png
deleted file mode 100644
index d8a592f..0000000
Binary files a/spec/factories/3.png and /dev/null differ
diff --git a/spec/factories/3.webp b/spec/factories/3.webp
index fc4e2ec..122741b 100644
Binary files a/spec/factories/3.webp and b/spec/factories/3.webp differ
diff --git a/spec/factories/6.jpg b/spec/factories/4.jpg
similarity index 100%
rename from spec/factories/6.jpg
rename to spec/factories/4.jpg
diff --git a/spec/factories/4.png b/spec/factories/4.png
deleted file mode 100644
index 1704ace..0000000
Binary files a/spec/factories/4.png and /dev/null differ
diff --git a/spec/factories/4.webp b/spec/factories/4.webp
index 8078123..a608fc8 100644
Binary files a/spec/factories/4.webp and b/spec/factories/4.webp differ
diff --git a/spec/factories/7.tif b/spec/factories/5.tif
similarity index 100%
rename from spec/factories/7.tif
rename to spec/factories/5.tif
diff --git a/spec/factories/5.webp b/spec/factories/5.webp
index 122741b..0f6dca1 100644
Binary files a/spec/factories/5.webp and b/spec/factories/5.webp differ
diff --git a/spec/factories/6.webp b/spec/factories/6.webp
deleted file mode 100644
index a608fc8..0000000
Binary files a/spec/factories/6.webp and /dev/null differ
diff --git a/spec/factories/7.webp b/spec/factories/7.webp
deleted file mode 100644
index 0f6dca1..0000000
Binary files a/spec/factories/7.webp and /dev/null differ
diff --git a/spec/webp_ffi_spec.rb b/spec/webp_ffi_spec.rb
index c572a4a..d957a26 100644
--- a/spec/webp_ffi_spec.rb
+++ b/spec/webp_ffi_spec.rb
@@ -2,10 +2,10 @@
 
 describe WebP do
   factories = {
-    webp: ["1", "2", "3", "4", "5", "6", "7"],
-    png: ["1", "2", "3", "4"],
-    jpg: ["5", "6"],
-    tiff: ["7"],
+    webp: ["1", "2", "3", "4", "5"],
+    png: ["1", "2"],
+    jpg: ["3", "4"],
+    tiff: ["5"],
     info: {
       "1" => {
         size: [400, 301],
@@ -16,22 +16,14 @@
         has_alpha: true
       },
       "3" => {
-        size: [300, 300],
-        has_alpha: true
-      },
-      "4" => {
-        size: [2000, 2353],
-        has_alpha: true
-      },
-      "5" => {
         size: [550, 368],
         has_alpha: false
       },
-      "6" => {
+      "4" => {
         size: [1024, 772],
         has_alpha: false
       },
-      "7" => {
+      "5" => {
         size: [1419, 1001],
         has_alpha: false
       }
@@ -42,6 +34,12 @@
     @out_dir = File.expand_path(File.join(File.dirname(__FILE__), "../tmp/"))
     Dir.mkdir(@out_dir) unless File.exists?(@out_dir)
   end
+  after :all do
+    @out_dir = File.expand_path(File.join(File.dirname(__FILE__), "../tmp/"))
+    #Dir["#{@out_dir}/*{.png,.webp}"].each do |file|
+    #  File.delete(file) rescue nil
+    #end
+  end
 
   it "calculate plus 100 by test_c (verify C)" do
     WebP::C.test_c(100).should == 200
@@ -105,24 +103,22 @@
         expect { WebP.encode(in_filename, out_filename) }.to raise_error WebP::EncoderError
       end
     end
-  end
-  
-  context "encode with options" do
-    factories[:png].each do |image|
-      it "#{image}.png image" do
-        in_filename = File.expand_path(File.join(File.dirname(__FILE__), "factories/#{image}.png"))
-        out_filename = File.expand_path(File.join(@out_dir, "#{image}.50png.webp"))
-        WebP.encode(in_filename, out_filename, quality: 50, method: 0, alpha_quality: 10, alpha_compression: 1)
+    context "with options" do
+      factories[:png].each do |image|
+        it "#{image}.png image" do
+          in_filename = File.expand_path(File.join(File.dirname(__FILE__), "factories/#{image}.png"))
+          out_filename = File.expand_path(File.join(@out_dir, "#{image}.50png.webp"))
+          WebP.encode(in_filename, out_filename, quality: 50, method: 0, alpha_quality: 10, alpha_compression: 1)
+        end
       end
     end
-  end
-  
-  context "raise EncoderError on invalid crop options" do
-    factories[:png].each do |image|
-      it "#{image}.png image" do
-        in_filename = File.expand_path(File.join(File.dirname(__FILE__), "factories/#{image}.png"))
-        out_filename = File.expand_path(File.join(@out_dir, "#{image}.invpng.webp"))
-        expect { WebP.encode(in_filename, out_filename, crop_w: 30000) }.to raise_error WebP::EncoderError
+    context "raise EncoderError on invalid crop options" do
+      factories[:png].each do |image|
+        it "#{image}.png image" do
+          in_filename = File.expand_path(File.join(File.dirname(__FILE__), "factories/#{image}.png"))
+          out_filename = File.expand_path(File.join(@out_dir, "#{image}.invpng.webp"))
+          expect { WebP.encode(in_filename, out_filename, crop_w: 30000) }.to raise_error WebP::EncoderError
+        end
       end
     end
   end
@@ -135,15 +131,46 @@
         WebP.decode(in_filename, out_filename).should be_true
       end
     end
-  end
-  
-  context "decode with output_format" do
-    [:pam, :ppm].each do |output_format|
-      factories[:webp].each do |image|
-        it "#{image}.webp image to #{output_format}" do
+    context "with output_format" do
+      [:png, :pam, :ppm, :pgm, :alpha_plane_only].each do |output_format|
+        factories[:webp].take(2).each do |image|
+          it "#{image}.webp image to #{output_format}" do
+            in_filename = File.expand_path(File.join(File.dirname(__FILE__), "factories/#{image}.webp"))
+            out_filename = File.expand_path(File.join(@out_dir, "#{image}.#{output_format}.png"))
+            WebP.decode(in_filename, out_filename, output_format: output_format).should be_true
+          end
+        end
+      end
+    end
+    context "with options" do
+      factories[:webp].take(2).each do |image|
+        it "#{image}.webp image to png and crop" do
           in_filename = File.expand_path(File.join(File.dirname(__FILE__), "factories/#{image}.webp"))
-          out_filename = File.expand_path(File.join(@out_dir, "#{image}.#{output_format}.png"))
-          WebP.decode(in_filename, out_filename, output_format: output_format).should be_true
+          out_filename = File.expand_path(File.join(@out_dir, "#{image}_crop.png"))
+          WebP.decode(in_filename, out_filename, crop_w: 200, crop_h: 200).should be_true
+        end
+        it "#{image}.webp image to png and scale" do
+          in_filename = File.expand_path(File.join(File.dirname(__FILE__), "factories/#{image}.webp"))
+          out_filename = File.expand_path(File.join(@out_dir, "#{image}_resize.png"))
+          WebP.decode(in_filename, out_filename, resize_w: 200, resize_h: 200).should be_true
+        end
+      end
+    end
+    context "raise DecoderError on invalid webp image" do
+      factories[:png].each do |image|
+        it "#{image}.png image" do
+          in_filename = File.expand_path(File.join(File.dirname(__FILE__), "factories/#{image}.png"))
+          out_filename = File.expand_path(File.join(@out_dir, "#{image}.invpng.webp"))
+          expect { WebP.decode(in_filename, out_filename) }.to raise_error WebP::DecoderError
+        end
+      end
+    end
+    context "raise DecoderError on invalid options" do
+      factories[:png].each do |image|
+        it "#{image}.png image" do
+          in_filename = File.expand_path(File.join(File.dirname(__FILE__), "factories/#{image}.png"))
+          out_filename = File.expand_path(File.join(@out_dir, "#{image}.invpng.webp"))
+          expect { WebP.decode(in_filename, out_filename, crop_w: 30000) }.to raise_error WebP::DecoderError
         end
       end
     end