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1answer
47 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 ...
0
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0answers
38 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 ...
0
votes
1answer
37 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 ...
0
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1answer
82 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 ...
1
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0answers
106 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 ...
0
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1answer
216 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 ...
0
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0answers
34 views

How to combine SURF and Harris points

As we know at Matlab, there is function to detect Harris or SURF feature individually. Then I need to combine these two list of features from both the Harris and SURF to make the matching more ...
0
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0answers
18 views

Log polar matching in extended space

Can somebody explain how the matching in "extended space", which is shown on page 1429 (figure 7c) in this document?. Is this just the same logpolar transformed image next to each other multiple times ...
0
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0answers
783 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 ...
0
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2answers
859 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. ...
1
vote
2answers
563 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 ...
4
votes
1answer
618 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 ...
5
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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 ...
2
votes
1answer
295 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 ...
2
votes
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
votes
1answer
156 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 ...
1
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0answers
621 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 ...
8
votes
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 ...
10
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1answer
210 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 ...
11
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2answers
577 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 ...