Signal Processing Stack Exchange
Signal Processing Stack Exchange

Questions tagged [image-processing]

In general, image processing is any form of signal processing for which the input is an image, such as a photograph or video frame.

Most image-processing techniques involve treating the image as a two-dimensional signal and applying standard signal-processing techniques to it. The output of image processing may be either an image or, a set of characteristics or parameters related to the image. Image processing usually refers to digital image processing, but optical and analog image processing also are possible.

Source: Wikipedia

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"River" detection in text

Over on the TeX stackexchange, we have been discussing how to detect "rivers" in paragraphs in this question. In this context, rivers are bands of white space that result from accidental alignment of interword spaces in the text. Since this can be…
Lev Bishop
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What does frequency domain denote in case of images?

I was just learning about the frequency domain in images. I can understand the frequency spectrum in case of waves. It denotes what frequencies are present in a wave. If we draw the frequency spectrum of $\cos(2\pi f t)$, we get an impulse signal…
Abid Rahman K
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Why do we use the HSV colour space so often in vision and image processing?

I see the HSV colour space used all over the place: for tracking, human detection, etc... I'm wondering, why? What is it about this colour space that makes it better than using RGB?
porridge
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What are some free alternatives to SIFT/ SURF that can be used in commercial applications?

As far as I understand, both SURF and SIFT are patent protected. Are there any alternative methods that can be used in a commercial application freely? For more info on the patent check…
Andrey Rubshtein
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Is deep learning killing image processing/computer vision?

I'm looking forward to enroll in an MSc in Signal and Image processing, or maybe Computer Vision (I have not decided yet), and this question emerged. My concern is, since deep learning doesn't need feature extraction and almost no input…
Tony
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What are some good signal and image processing blogs worth following?

Are there some good sites or blogs where I can keep myself updated on the latest news and papers about image and signal processing research, or I should just check out "classical" providers like IEEE Transactions, Elsevier, etc?
martjno
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Analogous Library to OpenCV for Audio Processing / Analysis

I understand OpenCV is the de facto library for programming image processing in C/C++; I'm wondering if there is a C or C++ library like that for audio processing. I basically want to filter raw waves from a microphone, and analyze them with some…
Tae-Sung Shin
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Best way of segmenting veins in leaves?

I have done a lot of research and found out methods like adaptive thresholding , watershed etc that can be used of detecting veins in leaves . However thresholding isn't good as it introduces a lot of noise All my images are gray image please could…
vini
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What algorithm does Google use for its "Search By Image" site?

What is your best guess how Google Image Search works? I can upload a photo and can search for similar images. What algorithm does it use to identify similar images?
Cory
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Point Pattern Recognition

Having two different size of sets of points (2D for simplicity) dispersed within two different size squares the question are that: 1- how to find any occurrence of the the small one through the large one? 2- Any idea on how to rank the occurrences…
Developer
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How to flatten the image of a label on a food jar?

I'd like to take pictures of labels on a jar of food, and be able to transform them so the label is flat, with the right and left side resized to be even with the center of the image. Ideally, I'd like to use the contrast between the label and the…
mahboudz
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What Properties Make Certain Wavelets "Better" Than Others In Image Compression?

I am trying to teach myself more about image compression using the wavelet transform method. My question is: What is it about certain wavelets that make them preferable when compressing images? Are they easier to compute? Do they produce smoother…
user807566
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What are the most common algorithms for adaptive thresholding?

Adaptive thresholding has been discussed in a few questions earlier: Adaptive Thresholding for liver segmentation using Matlab What are the best algorithms for document image thresholding in this example? Of course, there are many algorithms for…
Dipan Mehta
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What's the difference between the Hough and Radon transforms?

I'm familiar with the Radon transform from learning about CT scans, but not the Hough transform. Wikipedia says The (r,θ) plane is sometimes referred to as Hough space for the set of straight lines in two dimensions. This representation makes the…
endolith
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Finding squares in Image

I need to find the squares in an image using OpenCV (no problem in matlab or any other, generally what i expect are some ideas). Consider the test image below : I need to find those coloured squares in above image accurately (not the white long…
Abid Rahman K
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