title: Color space - RGB and YCbCr question
body: <p>I am now trying to understand how <code>JPEG</code> encoding works and everything seems fine except the color transformation part.</p>
  
  <p>Before attempting to do a <code>DCT</code> in <code>JPEG</code> algorithm, the image is transformed into <code>YCbCr</code> color space. To me this essentially means that we just (comparing to initial <code>RGB</code> image) take a chunk of color information and dispose it while applying the <code>RGB -&gt; YCbCr</code> transformation.</p>
  
  <p>So, our encoding steps look generally like <code>RGB -&gt; YCbCr -&gt; DCT -&gt; Huffman</code>. The decoding means inversing this process. </p>
  
  <p>And my question is - why does the image (for example, created and exported to <code>JPEG</code>) remain the same in terms of color, although we have to make inverse <code>YCbCr -&gt; RGB</code> transform. Where does the disposed part of color information comes from or how is it handled?</p>