As usual the article misrepresents video compression. Almost l useful coding tools are spatial and not frequency based; the only famous one (DCT) was replaced with a rough approximation in H.264 and it works just as well.
This is because lots of realistic images don't really have meaningful frequency-based content. (imagine sampling every 8 or 16 pixels - would their values be in any way related to each other?)
Next, each 8×8 block of each component (Y, Cb, Cr) is converted to a frequency-domain representation, using a normalized, two-dimensional type-II discrete cosine transform (DCT).http://en.wikipedia.org/wiki/JPEG
Comments
As usual the article misrepresents video compression. Almost l useful coding tools are spatial and not frequency based; the only famous one (DCT) was replaced with a rough approximation in H.264 and it works just as well.
This is because lots of realistic images don't really have meaningful frequency-based content. (imagine sampling every 8 or 16 pixels - would their values be in any way related to each other?)
Don't think of them in terms the full function. You can approximate a strait line by a small part of a long sine wave. http://www.wolframalpha.com/input/?i=Sin%28x%29++from+.01+to...
But, for a real world example look at jpeg.
Next, each 8×8 block of each component (Y, Cb, Cr) is converted to a frequency-domain representation, using a normalized, two-dimensional type-II discrete cosine transform (DCT). http://en.wikipedia.org/wiki/JPEG