casting to fix vs2010 compile error

apps/interactive-calibration/frameProcessor.cpp

@@ -253,8 +253,8 @@ CalibProcessor::CalibProcessor(cv::Ptr<calibrationData> data, captureParameters
     mCapuredFrames = 0;
     mNeededFramesNum = capParams.calibrationStep;
     mDelayBetweenCaptures = static_cast<int>(capParams.captureDelay * capParams.fps);
-    mMaxTemplateOffset = std::sqrt(std::pow(mCalibData->imageSize.height, 2) +
-                                   std::pow(mCalibData->imageSize.width, 2)) / 20.0;
+    mMaxTemplateOffset = std::sqrt(static_cast<float>(mCalibData->imageSize.height * mCalibData->imageSize.height) +
+                                   static_cast<float>(mCalibData->imageSize.width * mCalibData->imageSize.width)) / 20.0;
     mSquareSize = capParams.squareSize;
     mTemplDist = capParams.templDst;