adaptive filter FPGA

>On Jun 13, 3:09 pm, "cutemonster" <ckh...@hotmail.com> wrote:
>> >On Jun 10, 2:38 pm, "cutemonster" <ckh...@hotmail.com> wrote:
>> >> >So you want to display a stroke signal on monitor?
>> >> >Why you need to sample the X? Is it time dimension? Is it a
constant
>> >> >ramping, or ramping with retrace, or random?
>>
>> >> I have to sample x and y because it doesn't work like raster
signal.
>> It's
>> >> voltage varies in time. There is another signal input called
>> Unblank(TTL).
>> >> It turn on and off of XY signal.  
>>
>> >Have you tried to lock the sampling clocks to the unblank?
>>
>> No, I don't understand how to lock it with sampling clock.  Can you
please
>> explain?
>>
>> thanks
>
>Locking the clock to the unblank meaning that their phase relation is
>fixed.  For some reason I can't escape from the time dimension :)  If
>you just sample for 1 frame then probably you don't need to do
>locking.  Do you sample just 1 image then display it continuously on
>the raster?
>
>If you capture it as live video or multiple frames, then how can you
>tell which pixels belong to frame n, which belong to frames n+1, n
>+2,...
>
>Regards,
>
>
>
>

Yes, I tried synchronous and asynchronously to Unblank signal.  There are
two problems.  The first one is the noise itself with the stroke signal
and the second one is the stroke signal being drawn at the second time
doesn't being drawn at the exact position.  It's like one pixel toggling
between frames. 

Do you know which kind of filter fit the best in this situation?

thanks for you suggestion

On Jun 14, 11:17 am, "cutemonster" <ckh...@hotmail.com> wrote:

> Yes, I tried synchronous and asynchronously to Unblank signal.  There are
> two problems.  The first one is the noise itself with the stroke signal
> and the second one is the stroke signal being drawn at the second time
> doesn't being drawn at the exact position.  It's like one pixel toggling
> between frames.
>
> Do you know which kind of filter fit the best in this situation?
>
> thanks for you suggestion- Hide quoted text -
>
> - Show quoted text -

Sounds like you capture it as live video or multiple frames.  In such
case you would need to synchronize or lock the clock to a reference,
the unblank may be?  Having no idea what the unblank looks like so I
can't tell how to do it, how often does the unblank recycling?

Having a good synchronized clock with low jitter is, IMHO, much easier
than doing the filter to minimize the artifact of pixels toggling
positions between frames

For the spatial noise, If I was you I would try a high order analog
filter infront of the A2D first, before doing any digital filtering

Regards,

>On Jun 14, 11:17 am, "cutemonster" <ckh...@hotmail.com> wrote:
>
>> Yes, I tried synchronous and asynchronously to Unblank signal.  There
are
>> two problems.  The first one is the noise itself with the stroke
signal
>> and the second one is the stroke signal being drawn at the second time
>> doesn't being drawn at the exact position.  It's like one pixel
toggling
>> between frames.
>>
>> Do you know which kind of filter fit the best in this situation?
>>
>> thanks for you suggestion- Hide quoted text -
>>
>> - Show quoted text -
>
>Sounds like you capture it as live video or multiple frames.  In such
>case you would need to synchronize or lock the clock to a reference,
>the unblank may be?  Having no idea what the unblank looks like so I
>can't tell how to do it, how often does the unblank recycling?
>
>Having a good synchronized clock with low jitter is, IMHO, much easier
>than doing the filter to minimize the artifact of pixels toggling
>positions between frames
>
>For the spatial noise, If I was you I would try a high order analog
>filter infront of the A2D first, before doing any digital filtering
>
>Regards,
>
>
>
>

thanks for the suggestion. For analog filtering, all I can do now is
putting a circuit in breadboard. The problem is that it's a couple inches
away from ADC. For digital filtering,  are they all very similar?  I mean,
there are many type of digital filtering and I'm confused which one I
should use.  Are they specifically work for certain application?

thanks,