is there an error in my use of cv::dct?
<p>I'm trying to use the <code>cv::dct</code> function. I create a new matrix, apply the dct to it and display the result:</p>

<pre><code>cv::Mat_&lt;float&gt; mTest = cv::Mat_&lt;float&gt;(mTest);
cv::Mat_&lt;float&gt; mTestCV(8, 8);


cv::dct(mTest, mTestCV);

std::cout &lt;&lt; "-----CV-----" &lt;&lt; std::endl;
for (int u = 0; u &lt; mTest.rows; u++) {
    for (int v = 0; v &lt; mTest.cols; v++) {
        std::cout &lt;&lt; (mTestCV.at&lt;float&gt;(u, v));
        std::cout &lt;&lt; ",";
    }
    std::cout &lt;&lt; "" &lt;&lt; std::endl;
}
</code></pre>

<p>And here's the result (int the second matrix):
<a href="https://i.stack.imgur.com/bzEUf.png" rel="nofollow"><img src="https://i.stack.imgur.com/bzEUf.png" alt="enter image description here"></a></p>

<p>Is there an error somewhere? Where does that 1640 come from?</p>