diff --git a/plugins/GSdx/GSTextureOGL.cpp b/plugins/GSdx/GSTextureOGL.cpp
index bf3ab7d8ba..4d29d5fb90 100644
--- a/plugins/GSdx/GSTextureOGL.cpp
+++ b/plugins/GSdx/GSTextureOGL.cpp
@@ -520,25 +520,37 @@ void GSTextureOGL::SavePNG(const string& fn, const void* image, uint32 pitch) {
 	} else {
 		png::image<png::rgba_pixel> img(m_size.x, m_size.y);
 		png::image<png::rgb_pixel>  img_opaque(m_size.x, m_size.y);
+		png::image<png::gray_pixel> img_alpha(m_size.x, m_size.y);
 
 		uint8* data = (uint8*)image;
 		for(int h = 0; h < m_size.y; h++, data += pitch) {
 			for (int w = 0; w < m_size.x; w++) {
-				png::rgba_pixel pa(data[4*w+0], data[4*w+1], data[4*w+2], data[4*w+3]);
-				img.set_pixel(w, h, pa);
+#if !defined(ENABLE_OGL_PNG_OPAQUE) && !defined(ENABLE_OGL_PNG_ALPHA)
+				png::rgba_pixel p(data[4*w+0], data[4*w+1], data[4*w+2], data[4*w+3]);
+				img.set_pixel(w, h, p);
+#endif
 
 #ifdef ENABLE_OGL_PNG_OPAQUE
-				png::rgb_pixel p(data[4*w+0], data[4*w+1], data[4*w+2]);
-				img_opaque.set_pixel(w, h, p);
+				png::rgb_pixel po(data[4*w+0], data[4*w+1], data[4*w+2]);
+				img_opaque.set_pixel(w, h, po);
+#endif
+#ifdef ENABLE_OGL_PNG_ALPHA
+				png::gray_pixel pa(data[4*w+3]);
+				img_alpha.set_pixel(w, h, pa);
 #endif
 			}
 		}
 
-		std::string rename = fn;
-		img.write(rename.replace(fn.length()-4, 4, "_full.png"));
+		std::string root = fn;
+		root.replace(fn.length()-4, 4, "");
+#if !defined(ENABLE_OGL_PNG_OPAQUE) && !defined(ENABLE_OGL_PNG_ALPHA)
+		img.write(root + "_full.png");
+#endif
 #ifdef ENABLE_OGL_PNG_OPAQUE
-		rename = fn;
-		img_opaque.write(rename.replace(fn.length()-4, 4, "_opaque.png"));
+		img_opaque.write(root + "_opaque.png");
+#endif
+#ifdef ENABLE_OGL_PNG_ALPHA
+		img_alpha.write(root + "_alpha.png");
 #endif
 	}
 }
diff --git a/plugins/GSdx/GSTextureSW.cpp b/plugins/GSdx/GSTextureSW.cpp
index 173fa958c5..605e814614 100644
--- a/plugins/GSdx/GSTextureSW.cpp
+++ b/plugins/GSdx/GSTextureSW.cpp
@@ -124,25 +124,37 @@ struct BITMAPINFOHEADER
 void GSTextureSW::SavePNG(const string& fn) {
 	png::image<png::rgba_pixel> img(m_size.x, m_size.y);
 	png::image<png::rgb_pixel>  img_opaque(m_size.x, m_size.y);
+	png::image<png::gray_pixel> img_alpha(m_size.x, m_size.y);
 
 	uint8* data = (uint8*)m_data;
 	for(int h = 0; h < m_size.y; h++, data += m_pitch) {
 		for (int w = 0; w < m_size.x; w++) {
-			png::rgba_pixel pa(data[4*w+0], data[4*w+1], data[4*w+2], data[4*w+3]);
-			img.set_pixel(w, h, pa);
+#if !defined(ENABLE_OGL_PNG_OPAQUE) && !defined(ENABLE_OGL_PNG_ALPHA)
+			png::rgba_pixel p(data[4*w+0], data[4*w+1], data[4*w+2], data[4*w+3]);
+			img.set_pixel(w, h, p);
+#endif
 
 #ifdef ENABLE_OGL_PNG_OPAQUE
-			png::rgb_pixel p(data[4*w+0], data[4*w+1], data[4*w+2]);
-			img_opaque.set_pixel(w, h, p);
+			png::rgb_pixel po(data[4*w+0], data[4*w+1], data[4*w+2]);
+			img_opaque.set_pixel(w, h, po);
+#endif
+#ifdef ENABLE_OGL_PNG_ALPHA
+			png::gray_pixel pa(data[4*w+3]);
+			img_alpha.set_pixel(w, h, pa);
 #endif
 		}
 	}
 
-	std::string rename = fn;
-	img.write(rename.replace(fn.length()-4, 4, "_full.png"));
+	std::string root = fn;
+	root.replace(fn.length()-4, 4, "");
+#if !defined(ENABLE_OGL_PNG_OPAQUE) && !defined(ENABLE_OGL_PNG_ALPHA)
+	img.write(root + "_full.png");
+#endif
 #ifdef ENABLE_OGL_PNG_OPAQUE
-	rename = fn;
-	img_opaque.write(rename.replace(fn.length()-4, 4, "_opaque.png"));
+	img_opaque.write(root + "_opaque.png");
+#endif
+#ifdef ENABLE_OGL_PNG_ALPHA
+	img_alpha.write(root + "_alpha.png");
 #endif
 }
 #endif
diff --git a/plugins/GSdx/config.h b/plugins/GSdx/config.h
index f65c192687..b24395598f 100644
--- a/plugins/GSdx/config.h
+++ b/plugins/GSdx/config.h
@@ -39,11 +39,11 @@
 //#define DISABLE_DATE
 
 // Allow to dump texture as PNG (require libpng++). It reduces the size of the dump
-// and alpha is well supported
+// and alpha is well supported (on linux)
 //#define ENABLE_OGL_PNG
-// Extension of the previous define to also dump texture without alpha (hard to see anything
-// when the texture is fully transparent)
+// The next two define allows to dump texture without alpha or only the alpha channel.
 //#define ENABLE_OGL_PNG_OPAQUE
+//#define ENABLE_OGL_PNG_ALPHA
 
 #if defined(_DEBUG) || defined(_DEVEL)
 #define ENABLE_OGL_DEBUG   // Create a debug context and check opengl command status. Allow also to dump various textures/states.