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0answers
20 views

Feature Descriptor for Hough Transform

I'm trying to implement rotation/scale invariant Generalized Hough Transform (i.e. template-matching algorithm). The main problem of this approach is computational complexity (it requires at least ...
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1answer
58 views

How to find a noisy line in a picture

Hi I would like to find a line in a noisy image as showed bellow. I tried gabor filter and cany edge detection, but it didn't produce anything usefull. I am looking for lines of specific orientation ...
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0answers
46 views

Histogram matching

I am implementing histogram matching program with 3 RGB color channel. My choice for the RGB histogram instead of HSV is only about understanding. To process this matching, I calculate 2 histograms ...
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1answer
45 views

Are there any template matching / optical flow algorithms for large image displacement?

I had some success with feature-based methods for image registration, but these methods are sometimes unsuitable (e.g. images containing repetitive patterns, very low contrast, low texture, no ...
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1answer
100 views

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 ...
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0answers
127 views

Why correlation coefficient template matching perfoms better than cross-correlation and square-differences method

I am using this template in OpenCv's match template function by converting all images to grayscale. Here are my result using sum of square differences,cross correlation and correlation ...
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1answer
238 views

Baseline correlation for template matching

In normal cross-correlation or convolution between a signal and a template(say a small portion of the signal) the template is moved along length of the signal without changing the amplitude offset of ...
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0answers
805 views

Why Normalized Cross Correlation Score of different templates is high?

I am using OpenCv's built in template matching function to search for an object in image. I am using Normalized Cross Correlation Method.The function is returning a value which I think indication of ...
0
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1answer
41 views

Avoid saturated pixels in cross-correlation computation

I am doing template maching using Normalized Cross-Correlation for measuring similarity between template and image. However, some images from my dataset contain saturated pixels (overshoot) which ...
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2answers
893 views

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. ...
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2answers
582 views

fast 2D cross correlation algorithm

I want to match a small template to a larger image, that the distance between the template and the subimage with the same size of the template is minimized. It can be solved directly or by applying 2D ...
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1answer
629 views

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 ...
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2answers
2k views

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 ...
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1answer
304 views

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 ...
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1answer
1k views

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 ...
6
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1answer
160 views

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 ...
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0answers
625 views

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 ...
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3answers
8k views

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 ...
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1answer
211 views

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 ...
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2answers
578 views

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 ...