4,379 questions with no upvoted or accepted answers
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### When does the laugh track kick in?

One of my weekend projects has brought me into the deep waters of signal processing. As with all my code projects that require some heavy-duty math, I'm more than happy to tinker my way to a solution ...
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### Will an Unscented Kalman Filter Be “As Good” as Other Optimization Algorithms for This Problem?

I want to calibrate a tri-axis magnetometer when a tri-axis gyroscope is also available. I am fairly certain I can solve this problem using various optimisation algorithms, but I would prefer to use ...
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### 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 c-...
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### Help in Retraining a HOG Descriptor using SVMLight

I am currently trying to count cars using OpenCV 2.4.4 with a HOG descriptor. Because a model for car detection is not available in OpenCV, I am creating my own model using SVMLight and a dataset of ...
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### 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: ...
I am trying to better understand the first-order low pass filter: Summary: Per wikipedia, a first order low pass filter yields the following in discrete time: $$\frac{Y(s)}{U(s)}= \frac{\omega_{c}}... 2answers 798 views ### Calculating the SNR of a blurred image I have a blurred and noisy image X, I want to apply the Wiener filter on it and get a deblurred and denoised image Y (i.e apply inverse of blurring filter while at the same time reducing some ... 0answers 250 views ### What's the similarities and differences between Wigner transform and wavelet transform? Wigner transform and continuous wavelet transform are both some kind of time-frequency representation of a signal. What are the similarities and differences between them? Could you give some ... 0answers 82 views ### Converting very short “motionless” video frames to single, better-resolved, images I made a mistake with my newly bought compact camera, before a trip to Japan. Instead of taking single pictures, I ended up with a few short "MP4" video files (1 second, 2-3 frames). I could ... 1answer 1k views ### Issues with the smoothing operator in coherence estimation using the complex Morlet (Gabor) wavelet The goal I wish to compute the coherence estimate using the continuous wavelet transform (CWT) of a real-valued signal with the complex Morlet (a.k.a. Gabor) wavelet. I compute the cwt of the signal ... 2answers 477 views ### Efficient calculation of correlation function every N^{\rm th} point I would like to calculate a long correlation function of length say, 1e6 points. I have a prior knowledge that the correlation peak will be in point k*1000. Is there an efficient way to apply this ... 1answer 276 views ### Analytical Expression for Convolution of Two 2D DFTs I am trying to do an image analysis problem on some images, and I want to calculate some things in the frequency domain which are giving me problems. Say I have an (discrete) image I(x,y) of size ... 2answers 3k views ### Filter size vs. FFT size and Overlap add First of all I would like to say that : I'm new to DSP and in a "learning curve" hence the "basicness" of my questions. I've read as many posts/articles as possible on the ... 1answer 386 views ### Deconvolution Question on Article “Deriving Intrinsic Images from Image Sequences” by Yair Weiss there are n derivative filters: f_i, and denote f_i^r as f_i's reverse filter such that$$f_i(x,y)=f_i^r(-x, -y)$$r_i, f_i given, to find r from the equations:$$f_i * r = r_i, (1 \leq i \...
Let's say I have a time series $\{t_i, x_i\}$ where the $x_i$ are strictly increasing and the $t_i$ are not regularly spaced. I can define a differential operator as  \Delta_i = \frac{x_i-x_{i-1}...