Properly deal with alpha in image compression.

That fixes ros-perception#169
Pitt-RAS · Dec 30, 2017 · b211b33 · b211b33
1 parent db94c45
commit b211b33
Show file tree

Hide file tree

Showing 2 changed files with 34 additions and 22 deletions.
diff --git a/cv_bridge/src/cv_bridge.cpp b/cv_bridge/src/cv_bridge.cpp
@@ -467,15 +467,6 @@ CvImagePtr cvtColor(const CvImageConstPtr& source,
 
 /////////////////////////////////////// CompressedImage ///////////////////////////////////////////
 
-cv::Mat matFromImage(const sensor_msgs::CompressedImage& source)
-{
-    cv::Mat jpegData(1,source.data.size(),CV_8UC1);
-    jpegData.data     = const_cast<uchar*>(&source.data[0]);
-    cv::InputArray data(jpegData);
-    cv::Mat bgrMat     = cv::imdecode(data,cv::IMREAD_ANYCOLOR);
-    return bgrMat;
-}
-
 sensor_msgs::CompressedImagePtr CvImage::toCompressedImageMsg(const Format dst_format) const
 {
   sensor_msgs::CompressedImagePtr ptr = boost::make_shared<sensor_msgs::CompressedImage>();
@@ -523,23 +514,28 @@ void CvImage::toCompressedImageMsg(sensor_msgs::CompressedImage& ros_image, cons
 {
   ros_image.header = header;
   cv::Mat image;
-  if(encoding != enc::BGR8)
+  if (encoding == enc::BGR8 || encoding == enc::BGRA8)
   {
-      CvImagePtr tempThis = boost::make_shared<CvImage>(*this);
-      CvImagePtr temp = cvtColor(tempThis,enc::BGR8);
-      image = temp->image;
+    image = this->image;
   }
   else
   {
-      image = this->image;
+    CvImagePtr tempThis = boost::make_shared<CvImage>(*this);
+    CvImagePtr temp;
+    if (enc::hasAlpha(encoding))
+    {
+      temp = cvtColor(tempThis, enc::BGRA8);
+    }
+    else
+    {
+      temp = cvtColor(tempThis, enc::BGR8);
+    }
+    image = temp->image;
   }
-  std::vector<uchar> buf;
 
   std::string format = getFormat(dst_format);
   ros_image.format = format;
-  cv::imencode("." + format, image, buf);
-
-  ros_image.data = buf;
+  cv::imencode("." + format, image, ros_image.data);
 }
 
 // Deep copy data, returnee is mutable
@@ -549,11 +545,27 @@ CvImagePtr toCvCopy(const sensor_msgs::CompressedImageConstPtr& source,
   return toCvCopy(*source, encoding);
 }
 
-CvImagePtr toCvCopy(const sensor_msgs::CompressedImage& source,
-                    const std::string& encoding)
+CvImagePtr toCvCopy(const sensor_msgs::CompressedImage& source, const std::string& encoding)
 {
   // Construct matrix pointing to source data
-  return toCvCopyImpl(matFromImage(source), source.header, enc::BGR8, encoding);
+  const cv::Mat_<uchar> in(1, source.data.size(), const_cast<uchar*>(&source.data[0]));
+  // Loads as BGR or BGRA.
+  const cv::Mat rgb_a = cv::imdecode(in, cv::IMREAD_UNCHANGED);
+
+  switch (rgb_a.channels())
+  {
+    case 4:
+      return toCvCopyImpl(rgb_a, source.header, enc::BGRA8, encoding);
+      break;
+    case 3:
+      return toCvCopyImpl(rgb_a, source.header, enc::BGR8, encoding);
+      break;
+    case 1:
+      return toCvCopyImpl(rgb_a, source.header, enc::MONO8, encoding);
+      break;
+    default:
+      return CvImagePtr();
+  }
 }
 
 CvImageConstPtr cvtColorForDisplay(const CvImageConstPtr& source,

diff --git a/cv_bridge/test/CMakeLists.txt b/cv_bridge/test/CMakeLists.txt
@@ -3,7 +3,7 @@
 # add boost directories for now
 include_directories("../src")
 
-catkin_add_gtest(${PROJECT_NAME}-utest test_endian.cpp utest.cpp utest2.cpp test_rgb_colors.cpp)
+catkin_add_gtest(${PROJECT_NAME}-utest test_endian.cpp test_compression.cpp utest.cpp utest2.cpp test_rgb_colors.cpp)
 target_link_libraries(${PROJECT_NAME}-utest
   ${PROJECT_NAME}
   ${OpenCV_LIBRARIES}