Grayscale is 1 channel, but still tries to convert #28

OpenCV Error: Assertion failed (scn == 3 || scn == 4) in cvtColor, file /build/opencv-a9MBGW/opencv-2.3.1/modules/imgproc/src/color.cpp, line 2834
epicsThread: Unexpected C++ exception "/build/opencv-a9MBGW/opencv-2.3.1/modules/imgproc/src/color.cpp:2834: error: (-215) scn == 3 || scn == 4 in function cvtColor
" with type "N2cv9ExceptionE" in thread "CV1_Plugin_1" at Fri Feb 22 2019 17<>
terminate called after throwing an instance of 'cv::Exception'
what(): /build/opencv-a9MBGW/opencv-2.3.1/modules/imgproc/src/color.cpp:2834: error: (-215) scn == 3 || scn == 4 in function cvtColor

prosilicaApp: abort due to signal 6 (SIGABRT) "Abort"...