Thanks for the info Maurice.
after a lot of testing...I got the image.
it has something to do with the resampling filter that downsamples the 
data to a size that can be proecessed by FFT.
Thanks again

Jeff

Maurice Givens wrote:
> It is my understanding that the MRI uses the Radon transform for image
> projection.  Therefor you need the inverse Radon transform.  Do a
> google search on radon transform.  There are some good papers there.
> 
> Maurice Givens
> 
> 
> "Jefferson O. Siy" <jeffsiy@pacific.net.ph> wrote in message news:<bolr7v$ri2$1@nobel2.pacific.net.sg>...
> 
>>I got an MRI raw data. Now how do I convert it to an MRI image?
>>
>>These are the current steps that I follow :
>>1. translation of data to
>>	R = input[i]*Cos((2*pi*f)*n/N)
>>	I = input[i]*Sin((2*pi*f)*n/N)
>>2. Zero pad the R and I data to reach data size allowable for FFT
>>3. perform a Horizontal then a Vertical FFT
>>4. get the absolute value of R and I
>>
>>
>>Unfortunately, all I get is NO Image.
>>
>>
>>Anything I missed here??
>>
>>also there are parameters that makes no sense to me, sampling rate, AD 
>>samples, taps.
>>I understand thet qd points and qd cycle are used for the cosine and 
>>sine tables.
>>Thanks
>>
>>Jeff

It is my understanding that the MRI uses the Radon transform for image
projection.  Therefor you need the inverse Radon transform.  Do a
google search on radon transform.  There are some good papers there.

Maurice Givens


"Jefferson O. Siy" <jeffsiy@pacific.net.ph> wrote in message news:<bolr7v$ri2$1@nobel2.pacific.net.sg>...
> I got an MRI raw data. Now how do I convert it to an MRI image?
> 
> These are the current steps that I follow :
> 1. translation of data to
> 	R = input[i]*Cos((2*pi*f)*n/N)
> 	I = input[i]*Sin((2*pi*f)*n/N)
> 2. Zero pad the R and I data to reach data size allowable for FFT
> 3. perform a Horizontal then a Vertical FFT
> 4. get the absolute value of R and I
> 
> 
> Unfortunately, all I get is NO Image.
> 
> 
> Anything I missed here??
> 
> also there are parameters that makes no sense to me, sampling rate, AD 
> samples, taps.
> I understand thet qd points and qd cycle are used for the cosine and 
> sine tables.
> Thanks
> 
> Jeff

I got an MRI raw data. Now how do I convert it to an MRI image?

These are the current steps that I follow :
1. translation of data to
	R = input[i]*Cos((2*pi*f)*n/N)
	I = input[i]*Sin((2*pi*f)*n/N)
2. Zero pad the R and I data to reach data size allowable for FFT
3. perform a Horizontal then a Vertical FFT
4. get the absolute value of R and I


Unfortunately, all I get is NO Image.


Anything I missed here??

also there are parameters that makes no sense to me, sampling rate, AD 
samples, taps.
I understand thet qd points and qd cycle are used for the cosine and 
sine tables.
Thanks

Jeff