From 8a88ded7b9b6f0582423e99f939ce5fb89967b7b Mon Sep 17 00:00:00 2001
From: David Yackzan <dwyackzan@gmail.com>
Date: Fri, 31 Jan 2025 13:06:48 -0700
Subject: [PATCH] Enable grayscale encoding in LibavStreamer

---
 src/image_streamer.cpp | 4 ----
 src/libav_streamer.cpp | 8 +++++++-
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/src/image_streamer.cpp b/src/image_streamer.cpp
index 564e1dc..520ad5d 100644
--- a/src/image_streamer.cpp
+++ b/src/image_streamer.cpp
@@ -148,10 +148,6 @@ cv::Mat ImageTransportImageStreamer::decodeImage(
     cv::Mat_<float> float_image = float_image_bridge;
     double max_val;
     cv::minMaxIdx(float_image, 0, &max_val);
-
-    if (max_val > 0) {
-      float_image *= (255 / max_val);
-    }
     return float_image;
   } else {
     // Convert to OpenCV native BGR color
diff --git a/src/libav_streamer.cpp b/src/libav_streamer.cpp
index 62f293f..211a163 100644
--- a/src/libav_streamer.cpp
+++ b/src/libav_streamer.cpp
@@ -225,7 +225,13 @@ void LibavStreamer::sendImage(
     first_image_time_ = time;
   }
 
-  AVPixelFormat input_coding_format = AV_PIX_FMT_BGR24;
+  AVPixelFormat input_coding_format;
+  if (img.channels() == 1) {
+    img.convertTo(img, CV_32FC1);
+    input_coding_format = AV_PIX_FMT_GRAYF32;
+  } else {
+    input_coding_format = AV_PIX_FMT_BGR24;
+  }
 
   AVFrame * raw_frame = av_frame_alloc();
   av_image_fill_arrays(