How can we perform inverse quantization of a quantized matrix?

How will we write the code for inverse quantisation?

Answer 1

[John D'Errico]

You cannot do so. Once a number has been quantized, essentially truncated to a shorter number of decimal places, you can NEVER recover the digits that have been dropped. Period. That is information that has been discarded, thrown away, into the bit bucket and forever lost.

Suppose I told you a number is 3, after quantization to an integer? Is there any possible method to know the values of ALL of the digits that were dropped in the quantization process? Surely if this is possible, then it is also possible to know all of the digits of pi, merely by telling you the quantized value is 3. How, for example, do you know that the original number was pi, and not sqrt(10)?

In the case of quantization, all that you know is the original value lies in the set of all values that could have been quantized into what you now have. Lacking any more information, you are done.

You cannot write code to do the impossible.

[Chandvi Arora]

I didn't know inverse quantization is impossible. But, if it is true, then in the attached image, how to perform the inverse quantization step? I am stuck there. Is it simply the inverse of the quantization matrix? Please help me with it.