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Questions tagged [pattern]

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What would be the input data matrix and target data matrix in MATLAB Neural Network Pattern Recognition toolbox?

I am new to Neural Networks and have no prior experience of AI,ML or deep learning. Please help me out. I have data sets of 10 different kind of hand-motions(Gestures) from M1 to M10. Each hand-motion ...
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1answer
25 views

What principles to use, in order to create field that will be read by OCR?

I currently have an invoice, where some numbers are written by hand, and I would need to read them automatically. My past experience is that people who write numbers will them write in so many ...
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2answers
122 views

Identify random repetitive patterns

Forgive me if it’s too basic, I finish engineering a while ago. Given any time series, not periodic, I would like to find any repetitive pattern that is distinct (by some given measurement) and is ...
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1answer
52 views

How to programmatically find a sharp change in slope

First, apologies if I have the wrong group or this question is far too easy for this group. I am (as you'll see) a newbie. Please point me to another, more appropriate group OR tell me how to fix the ...
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1answer
42 views

Detect gradual increase then decrease in slightly noisy data

I have data thats not too noisy and I am trying to detect a pattern where it gradually increases then decreases in a short period of time (20 ticks? it should be roughly similar per session but can ...
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1answer
23 views

detection of periodicities in n-dimensional signals

Generally speaking, what analyses are necessary and sufficient for the detection of periodicities in an n-dimensional signal amounting to a discretely sampled density distribution over n-dimensional ...
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0answers
20 views

Remove clips from audio that match fingerprint

I have podcast audio files which contain ad breaks. Before and after each ad break, a distinct sound effect is played that lasts a couple of seconds. First, I want to know how I can locate all the ...
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0answers
129 views

Pattern recognition

I am new to the world of computer vision, so please excuse my basic questions. I have two patterns: one consisting of a single circle of radius $r$, and one made of several circles, still of radius $...
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1answer
39 views

Can Binary Content alone affect Noise Performance?

Assume we got a transmitter and a receiver. We send a binary stream of let's say 8 bits (the stream length cannot change), using AM-modulation. We have no info on the channel/noise characteristics. ...
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1answer
72 views

Neural Network learning project based on 8 wave signals over 1 second at 1 sample every 10 ms ( hence 100Hz )

I'm currentely trying to train a neural network that can decide wether a pattern produced by the movement of a hand near capacitive sensors is as expected, or random. I have an MPR121 microchip linked ...
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0answers
85 views

Approach to identify someone knocking on a door - preferably not using a neural network

Say I wanted to identify someone knocking at my door using a microphone. I have (or at least I can make) some pretty good examples of what the signal looks like, but of course it will vary from person ...
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1answer
41 views

Engine for Google / Browsers to detect manipulated images? [closed]

Would it be possible for Google and web browsers to scan images and detect doctored photos? For example, a web browser could check for abnormal color gradients and signals that indicate if a photo ...
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1answer
252 views

Pattern matching methods: Based on Area and Based on features

Good morning, I'm new to image processing and I'm currently working on a project for pattern matching and OCR more specifically. In the state of art I've found the matching process can be classified ...
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0answers
39 views

Determining periodic pattern when there is pattern which period is multiple of former

I have periodic signal, say, it has year period, yearly pattern. I want to check if also has quarterly pattern. Event if there is no visible quarterly pattern, Fourier Transform of this signal has ...
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1answer
38 views

Finding a change in a signal

I am looking to some C algorithm(for MCU), where I have these signals : First graph you can see that there is an event in the middle and it goes back to normal, second and third there is some event ...
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1answer
183 views

How to detect lines arranged in a visual pattern in an image?

I have a black and white image like this: Visually, there is a clear pattern of black lines evenly separated by somewhat thicker white lines. The problem I need to solve is to automatically detect ...
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1answer
973 views

Why does this Moiré pattern look like this?

I was making some gifs of Mobius transformations in Matlab, and some strange patterns began to appear. I'm not sure if a deeper knowledge of the filetype/algorithm is needed to understand this ...
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1answer
632 views

Find a small image pattern in another similar image

I have this pattern in the first image which I want to find in the second image. However the two images are totally different so I just need to find the closest set of indices where these two images ...
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0answers
121 views

Feature recognition within a single song

I want to write an algorithm in C++ which is capable of identifying specific features within a single song, e. g. the sound of a drum which is played 100 times during 5 min. State of the project So ...
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2answers
3k views

Which image filter can be applied to remove gridded pattern from corrupt jpegs?

I have around 1,400 jpegs that have been corrupted somehow and have lost the backup images. They all seem to have the same gridded pattern of lines over each (i.e. the gridding does not shift from ...
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0answers
165 views

Cross Correlation shows peak at the same location every time

I have a signal which is taken from an accelerometer and I'm trying to match patterns between different windows of the signal by cross correlation. To do this I take different windows of the signal, ...
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2answers
78 views

Question regarding using cardinality in pattern recognition

So I've read this article for a project im working on: Ortiz-Cataln: Cardinality as a highly descriptive feature in myoelectric pattern recognition for decoding motor volition, Chalmers Uni, ...
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1answer
123 views

Detecting expected patterns in repeated measurements

I am new to signal processing and I am trying to learn myself. To understand what i am interested in, let me show this on example (note that this is just a random example to illustrate). Here is some ...
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2answers
187 views

Measure similarity between quantized grayscale images

I want to measure the similarity between quantized grayscale images (8 levels) that mostly depict organic patterns found in nature, say pigmentation patterns in animals (zebra pattern, leopard spots,.....
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2answers
421 views

Filling hatched areas in image

I'm trying to extract / fill the walls in a floor plan, the walls are filled with a (cross-)hatch pattern at a more or less fixed angle. I've managed to remove most of the "noise" by masking the DFT ...
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0answers
53 views

How accurate is Wavelet packet decomposition for emg signals with frequencies from 10 to 40 Hz?

I have an electromyographic signal sampled at a frequency between 10 and 40 Hz in a time window of 300ms. Is wavelet packet decomposition adequate in order to perform features extraction for ...