diff --git a/mediapipe/calculators/image/color_convert_calculator.cc b/mediapipe/calculators/image/color_convert_calculator.cc
index f31586d9d..7891463c0 100644
--- a/mediapipe/calculators/image/color_convert_calculator.cc
+++ b/mediapipe/calculators/image/color_convert_calculator.cc
@@ -57,6 +57,8 @@ constexpr char kGrayOutTag[] = "GRAY_OUT";
 //   RGB  -> RGBA
 //   RGBA -> BGRA
 //   BGRA -> RGBA
+//   RGBA -> GRAY
+
 //
 // This calculator only supports a single input stream and output stream at a
 // time. If more than one input stream or output stream is present, the
@@ -196,6 +198,12 @@ REGISTER_CALCULATOR(ColorConvertCalculator);
                             cv::COLOR_RGBA2BGRA, cc);
   }
 
+  // RGBA -> GRAY
+  if (cc->Inputs().HasTag(kRgbaInTag) && cc->Outputs().HasTag(kGrayOutTag)) {
+      return ConvertAndOutput(kRgbaInTag, kGrayOutTag, ImageFormat::GRAY8,
+                              cv::COLOR_RGBA2GRAY, cc);
+  }
+
   return ::mediapipe::InvalidArgumentErrorBuilder(MEDIAPIPE_LOC)
          << "Unsupported image format conversion.";
 }
diff --git a/mediapipe/calculators/util/detection_unique_id_calculator.cc b/mediapipe/calculators/util/detection_unique_id_calculator.cc
index 2069f1677..fd58e5126 100644
--- a/mediapipe/calculators/util/detection_unique_id_calculator.cc
+++ b/mediapipe/calculators/util/detection_unique_id_calculator.cc
@@ -33,8 +33,8 @@ inline int GetNextDetectionId() { return ++detection_id; }
 }  // namespace
 
 // Assign a unique id to detections.
-// Note that the calculator will consume the input vector of Detection or
-// DetectionList. So the input stream can not be connected to other calculators.
+// Note that the calculator will consume or copy the input vector of Detection or
+// DetectionList. 
 //
 // Example config:
 // node {
@@ -76,7 +76,7 @@ REGISTER_CALCULATOR(DetectionUniqueIdCalculator);
   if (cc->Inputs().HasTag(kDetectionListTag) &&
       !cc->Inputs().Tag(kDetectionListTag).IsEmpty()) {
     auto result =
-        cc->Inputs().Tag(kDetectionListTag).Value().Consume<DetectionList>();
+        cc->Inputs().Tag(kDetectionListTag).Value().ConsumeOrCopy<DetectionList>();
     if (result.ok()) {
       auto detection_list = std::move(result).ValueOrDie();
       for (Detection& detection : *detection_list->mutable_detection()) {
@@ -93,7 +93,7 @@ REGISTER_CALCULATOR(DetectionUniqueIdCalculator);
     auto result = cc->Inputs()
                       .Tag(kDetectionsTag)
                       .Value()
-                      .Consume<std::vector<Detection>>();
+                      .ConsumeOrCopy<std::vector<Detection>>();
     if (result.ok()) {
       auto detections = std::move(result).ValueOrDie();
       for (Detection& detection : *detections) {