Unanswered Questions
5,284 questions with no upvoted or accepted answers
12
votes
0
answers
195
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 ...
- 31.6k
12
votes
0
answers
1k
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 c-...
9
votes
0
answers
1k
views
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 ...
- 1,964
8
votes
1
answer
9k
views
Calculating the SNR of Audio Signal (Recommended Libraries)
Are there any open source packages or libraries available which can be useful in calculating the SNR(signal to noise ratio) of an audio signal.
The input will be just an audio signal and I have to ...
CommunityBot
- 1
7
votes
0
answers
188
views
Avoid circular convolution aliasing in weighted overlap-add (WOLA) method
This link gives the procedure of implementing the WOLA method. It can be summarized briefly as windowing the extractd data frame, FFT, modify the spectrum, IFFT and overlap-add the windowed IFFT ...
- 359
7
votes
0
answers
293
views
Efficient Convolution Without I/O Delay (Gardner 1995) implementation
I am trying to perform real-time convolution on an audio stream using a fairly large FIR for convolutional reverb.
I found a great paper explaining how to do just that: Gardner, 1995. But, I'm new to ...
- 171
7
votes
1
answer
244
views
Filter design to realize Cauchy product
I come from Computer Science so please pardon for my possibly wrong terminology.
I need to design a filter which has coefficients
$$h_0, h_1, \ldots, h_n, \ldots \quad\text{such that}\quad h_0 > ...
CommunityBot
- 1
7
votes
1
answer
383
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 $...
CommunityBot
- 1
6
votes
0
answers
78
views
Other Examples of Complete Orthonormal Systems
I am interested in other examples of finite and complete orthogonal basis. I am not confident in my use of the term “complete”, so what I mean specifically is a set of basis vectors that can be used ...
- 48.2k
6
votes
1
answer
176
views
Signal Reconstruction in Compressed Sensing with a Simple Vector Signal as an Example
While going through the different types of reconstruction algorithm as mentioned in Richard G. Baraniuk - Compressive Sensing - Lecture Notes (Also on DocDroid), I came to know that minimum $ {L}_{1} $...
CommunityBot
- 1
6
votes
1
answer
1k
views
Eigen Values and Eigen Vectors in Image Processing
I have been reading about eigen values and eigen vectors but I haven't been able to find any decent explanation relating their application in Image Processing / Computer Vision.
For example, How can ...
CommunityBot
- 1
6
votes
1
answer
1k
views
How Can I Detect Peaks and Regions of Highest Variance in a 1D Signal?
I'm not a signal processing person at all so hopefully I'm not asking an obvious question (if I am, I'd appreciate any resources that would help give more context).
I have a 1D vector where the ...
CommunityBot
- 1
6
votes
0
answers
2k
views
Jacobian Matrix of a Quaternion $q$ respect to Angular Velocity $\omega$
In the context of visual tracking and video processing I need to estimate variations of the orientation related to the angular velocity. I am trying to calculate the Jacobian matrix of a quaternion $\...
- 1,203
6
votes
0
answers
193
views
EWMA based differential that is strictly positive on strictly increasing irregular time series?
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}...
- 161
6
votes
1
answer
1k
views
detect what is noise in audio signal
I'm trying to filter noise from an audio signal. The signal was and is going to be recorded in a city environment which always contains some white/pink noise.
At this moment I'm using two options to ...
- 25k