Merge pull request #27628 from asmorkalov:as/grayscale_calib

Convert grayscale frames into color in interactive calibration preview

apps/interactive-calibration/frameProcessor.cpp

@@ -308,7 +308,10 @@ cv::Mat CalibProcessor::processFrame(const cv::Mat &frame)
 {
     cv::Mat frameCopy;
     cv::Mat frameCopyToSave;
-    frame.copyTo(frameCopy);
+    if (frame.channels() == 1)
+        cv::cvtColor(frame, frameCopy, cv::COLOR_GRAY2BGR);
+    else
+        frame.copyTo(frameCopy);
     bool isTemplateFound = false;
     mCurrentImagePoints.clear();