Smoothing only peaks in a Curve

Hello,

The curve I have is shown in the image. Is there a way I could smooth only the peak, which is around the X=800 mark, ideally keeping the rest of the data as the raw signals.

In case I decide to join a raw and a smoothed curve (using a filter), the problem then I face is the joining point of the raw curve and the smoothed curve, which shows a step (undesired).

I would like to ideally keep the raw data till X=720 (point where constant rise starts), then continue with the raw data through the constant slope, i.e from x=720 to the point where smoothing of the peak starts, perform a smoothing with a factor and rejoin back with the raw data once the smoothing is done (keeping that step in mind again).

I was talking to one of the correspondents and it was nice of him to help me out on this thread, http://www.mathworks.com/matlabcentral/answers/116391-smoothing-only-a-part-of-a-curve#answer_124995 but I'm kinda needing an urgent answer, and if possible today.

Could anyone out there help me out on this one?

Regards,

Anirudh

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/29922-why-your-question-is-not-urgent-or-an-emergency

Answer 1

[Nitin]

Did you check the smooth function?

Answer 2

[Image Analyst]

Just smooth the whole thing, say with conv() to do a sliding average or with sgolay to so a sliding polynomial Savitzky-Golay filter. Then replace the original pixels with the smoothed one in the range you want

smoothedSignal = conv(originalSignal, ones(1,9), 'same'); % or whatever
newSignal = originalSignal; % Initialize
% Replace region of interest with smoothed values.
newSignal(index1:index2) = smoothedSignal(index1:index2); % You determine the indexes in some way.

[Anirudh]

Thanks,

But as I said, I'm still not getting a clear convergence (without a step) when I join a certain smoothed part to the raw signals.

[Image Analyst]

Post your data so people can try things with it.

[Image Analyst]

Anirudh, what's the status of this? Are we done? Do you need a more comprehensive demo? Did I answer your question?

[Anirudh]

Image Analyst, Thanks for writing back :).

I used the conv() function, smoothed the curve and replaced only a certain smoothed part (say X=750 to X=820), in the raw signals. I then smoothed this entire curve once again to eliminate the steps at X=750 and X=820.

But this is not a very convincing method as I'm deviating from the original values by more, so I'm still on the lookout for a better solution to this.

Thanks, Anirudh