-Support the TRNS flag on libpng, fixes #3097

drivers/png/image_loader_png.cpp

@@ -124,6 +124,13 @@ Error ImageLoaderPNG::_load_image(void *rf_up,png_rw_ptr p_func,Image *p_image)
 		png_read_update_info(png, info);
 	}
 
+	if (png_get_valid(png,info,PNG_INFO_tRNS)) {
+//		png_set_expand_gray_1_2_4_to_8(png);
+		png_set_tRNS_to_alpha(png);
+		png_read_update_info(png, info);
+		png_get_IHDR(png, info, &width, &height, &depth, &color, NULL, NULL, NULL);
+	}
+
 	int palette_colors = 0;
 	int palette_components = 0;
 	int components = 0;

tools/editor/property_editor.cpp

@@ -2045,7 +2045,7 @@ void PropertyEditor::set_item_text(TreeItem *p_item, int p_type, const String& p
 			if (img.empty())
 				p_item->set_text(1,"[Image (empty)]");
 			else
-				p_item->set_text(1,"[Image "+itos(img.get_width())+"x"+itos(img.get_height())+"]");
+				p_item->set_text(1,"[Image "+itos(img.get_width())+"x"+itos(img.get_height())+"-"+String(Image::get_format_name(img.get_format()))+"]");
 
 		} break;
 		case Variant::NODE_PATH: {
@@ -3007,7 +3007,7 @@ void PropertyEditor::update_tree() {
 				if (img.empty())
 					item->set_text(1,"[Image (empty)]");
 				else
-					item->set_text(1,"[Image "+itos(img.get_width())+"x"+itos(img.get_height())+"]");
+					item->set_text(1,"[Image "+itos(img.get_width())+"x"+itos(img.get_height())+"-"+String(Image::get_format_name(img.get_format()))+"]");
 				if (show_type_icons)
 					item->set_icon( 0,get_icon("Image","EditorIcons") );