signal compression whit FFT

[sigma10]

can you help me ?

thank you so much

[altenbach]

You have exactly the same number of bits in the input and output signal. You would only get some form of "compression" if you would somehow only store the values and locations of the nonzero elements in the frequency domain. This is then sufficient to regenerate the output signal at a later time.

[sigma10]

  thank you very much

here I found an example to the internet that gives the original signal, reconstructed and error. they are calculated and CR (compression ratio) and PRD (distortion)? So how can I calculated that 2 factors? 

see this image :

[sigma10]

the formula of the PRD ;

[sigma10]

hello

 The program for the compression of a signal by FFT, but it works well just for the synthetic signal, now I want to add a signal in the form of a file.txt .how can I do?

[sigma10]

Can you help me ?

[johnsold]

We are having trouble helping you because we cannot determine what you are trying to do.

1. Is this a school assignment?

2. What kind of compression are you trying to do?  Are you trying to reduce the number of data points necessary to represent a signal or are you trying to compress the dynamic range of the signal or something else?

3. FFT is not the usual tool for either kind of compression mentioned in question 2.  What doe the FFT have to do with this?

4. What else are you not telling us which would help us help you?  The more specific and the more detailed the information you provide, the more likely that someone can help.

Lynn

[sigma10]

hello
  Here is the program for the compression of a signal by FFT, but just for the syntheticsignals.
Now I want to add a signal type.txt

 this is my question: how I'm going to add the signal files?

[altenbach]

You are still not compressing anything, you are just filtering. What is the purpose of this execise?

Data is just data. It can come from a simulation of from a datafile, for example. What kind of problems do you have reading a file? What is the format of the file? Who wrote it? What have you tried?

[sigma10]

my goal is to compress an acoustic or seismic record is a file type. txt?