Unanswered Questions

14
votes
1answer
191 views

Using an error prediction filter for filtering a semi-known signal

I'm trying to wrap my head around the proper use of a Wiener or error-prediction filter for filtering data. It seems to me that it is only a whitening filter, so how is it used when the data you want ...
9
votes
0answers
360 views

Real-valued ringing when zero-padding odd-length FFT

So I'm trying to write a frequency-domain interpolator that zero-pads the frequency response of a signal and inverse transforms. There's two cases I have to deal with: Even-length response - have ...
9
votes
0answers
330 views

How do I implement an adpative thresholding algorithm for underwater sonar

I want to implement an adaptive thresholding algorithm in MATLAB for filtering data received by an underwater sonar receiver. The data received has an interactive noise component resulting from ...
8
votes
1answer
1k views

ADC performance simluation: How to calculate SINAD from FFT?

While working on this problem, I started to have doubts that my initial definition of $$SINAD = 10 \log_{10} \left( \frac{p_f} {\sum_i{(p_i)} - p_0 - p_f} \right)dB$$ is correct. In this equation, ...
8
votes
1answer
201 views

Kalman Filter - best way to handle “derived” measurements?

Ie, if you have as state variables position (p) and velocity (v), and I make low-frequency measurements of p, this also indirectly gives me information about v (since it's the derivative of p). What ...
8
votes
1answer
367 views

How to deal with a negative pole (unstable) in the pre-filter of a control system?

So while answering how to design a PI controller for a first order time delayed system (Question Here ) Here is the closed loop equation to a control system: $$ G_C(s) = ...
7
votes
0answers
698 views

Calculating a homography based on detected lines

I know you can calculate homographies from image to camera plane using correspondence points between a "perfect model" and the image points. I'm doing it for a football pitch/field, and have used ...
7
votes
0answers
411 views

Ensemble learning, multiple classifier system

I am trying to use a MCS (Multi classifier system) to do some better work on limited data i.e become more accurate. I am using K-means clustering at the moment but may choose to go with FCM (Fuzzy ...
7
votes
1answer
746 views

Derivative calculation

I have a series of data (single array). If I take this data and plot it, I can see that there are multiple peaks. However If I zoom in to a section of data, I see that there is substantial noise. I ...
6
votes
2answers
78 views

What's the underlying algorithm for detail-preserving upsampling in Photoshop CC?

The detail-preserving upsampling algorithm in Photoshop CC is truly amazing. It can upscale any image while preserving details in almost real-time. And I truly wonder how it is implemented. I've ...
6
votes
2answers
129 views

Removing marker pen artifacts from scanned microscope slide images

I am developing an image processing algorithm / plugin for Fiji (ImageJ) that processes scanned microscope slide images (20x magnification) and extracts features from the slides. The slides contain ...
6
votes
0answers
94 views

Estimating the input to a system from a system state using EKF

[ Cross-posted from: http://math.stackexchange.com/questions/164169/estimating-the-input-to-a-system-from-a-system-state ] I have a system for which I have obtained a non-linear time-varying ...
6
votes
0answers
328 views

How to find the lower eyelid in an image?

I have an image of 480x360 px that contains eye portion only i.e., sclera iris, pupil, eyebrows etc. Now I have to find the lower eyelid in the image. What I've done till now is that cut the image ...
6
votes
0answers
116 views

What is the normalization factor for the quincunx lattice wavelet transform, and how do you find it?

On pages 57-60 (preview was available last I checked, images here in case), there is a quincunx lattice transform described. Lattice: ...
6
votes
0answers
226 views

How do you choose the optimal number of taps in a windowed image scaling filter?

I'm attempting to use a filter to scale an image and for the most part, I have something that appears to work. But now I want to be able to generate a filter with an optimal number of taps. I know ...

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