Signal Processing Stack Exchange
Signal Processing Stack Exchange

Questions tagged [template-matching]

35 questions
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Scale and Rotation invariant Template Matching

I'm looking for a method for scale and rotation invariant Template matching. I already tried some, but they didn't work so good for my examples or took for ever to execute . SIFT and SURF Feature detection failed totally. I also tried to implement a…
Arndt Bieberstein
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Necessary image processing operations before template matching

Well, this may show I didn't take image processing class. I have this template to match an object in images. But real object in images, for example, does not look like that but the second image. What operations do I need to take for the images like…
Tae-Sung Shin
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How to Tell How Likely a Signal Is Present in Another One (Variance Unknown)?

I know this is probably a simple question, but I haven't been able to find a satisfactory answer anywhere... Say you have a time series signal of finite length N. Call it $y[n]$. It looks like a sine-gaussian perhaps but with some random effects. …
bill_e
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Advise on detecting anatomical landmarks in a CT reconstructed volume

I'm trying to automatically detect some medical defined anatomical landmarks in a CT reconstructed volume. Medical doctors use these landmarks to measure some patient specific parameters. I have attempted to use the SIFT feature descriptor, since…
Federico
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Using DTW on the MFCC's to match a spoken word to a template

I am trying to code a simple algorithm in MATLAB that would be used to detect a single word. The goal would be to have a user record the word one time to act as a template, then make the user repeat the same word to try and detect it. Searching on…
user5907
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Ambiguous results of phase correlation in pattern recognition

We are using phase correlation to find pattern on image and what we get is 15% of results is spurious. Ours pattern has 32x32 pixels and image for research has 32x512 pixels. So we put Pattern to 32x512 pixels image to the left side and the rest of…
Dawid D
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4 answers

Algorithm for Scale Invariant Template Matching

I am using opencv for finding template images in a video stream. The elements I am trying to find are UI elements of android apps. Classic template matching is working quite well. But only as long as the scene and the template share the same…
stoefln
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how could correlation-based image patches matching works?

In general, correlation-based image matching can be referred to as $$c(I_1,I_2) = \sum_{x \in patch} f(I_1(x), I_2(x))$$ , I do think normalized cross-correlation like $$ncc(I_1, I_2) = \sum_{x \in patch}\frac{(I_1(x) - \mu_1)(I_2(x) -…
avocado
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Questions about log polar transform

I read various papers about the log polar transform and its application on template matching with images and have some questions: In "Image Registration Using Log Polar Transform and Phase Correlation to Recover Higher Scale" the authors say: "In…
Chad Moklav
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How to recognize a zebra crossing from top view using OpenCV?

How to recognize a zebra crossing from top view using OpenCV? It is not a straight zebra crossing - it has some twists and turns. I have some ideas: parallel line detection, but the available techniques only work to find straight parallel lines,…
user1929880
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GPS CA Signal Acquisition

The coarse acquisition C/A GPS signal has a symbol rate or chip rate of 1.023 Mcps with code period of 1 ms. The code bandwidth is +/-1.023MHz (to 1st sinc nulls). I'd like to record this signal using a USRP. What's the minimum complex sample rate…
random_dsp_guy
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Difference between Generalized Hough Transform and Cross-correlation Feature Matching

I've been taking the Udacity Computer Vision Course, and one thing that has confused me so far is how the Generalized Hough Transform is any different from feature matching on an edge image using cross-correlation. As I understand, the Generalized…
Peter Moran
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Feature matching of images without corners

I am trying to stitch aerial images using feature-based registration. Most image pairs are matched well, such as this: Others are not matched due to lack of common features: As you can see, the images contain almost no corners (only fuzzy…
Libor
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Find reappearing pattern in the signal

I am working with a signal that describes energy consumption in some house as a function of time and I am trying to find time intervals that correspond to some particular type of dish washer. What do we know about this dish washer: It has 4 heating…
Vladimir
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Template matching or object recognition?

Problem: I have a photo of an object (a manufactured part like the attached photo below), using my Andoird phone camera I want to verify if the object in camera preview matches to the template or not. (in other words, is it the same part as the…
Asha
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