OpenCV not filling entire image
===

I have a strange problem with OpenCV. Here's the code:

        cv::Mat cvSideDepthImage1(150, 150, CV_8UC1, cv::Scalar(100));
        cv::imshow("side1", cvSideDepthImage1);

Based on the [documentation for `cv::Mat`][1], I would expect this to show a 150x150 image with all pixels set to 100 (so the whole picture should be gray).

Instead I get this:

![enter image description here][2]

What am I doing wrong?


  [1]: http://opencv.willowgarage.com/documentation/cpp/basic_structures.html
  [2]: http://i.stack.imgur.com/HetAA.png