Computer Science Stack Exchange
Computer Science Stack Exchange

Questions tagged [digital-image-processing]

21 questions
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Minimum spanning tree between blobs

We have a binary raster image in which we consider the white blobs (connected components). We define a distance between two blobs to be the length of the shortest path between any two respective pixels (topological distance), or alternatively the…
user16034
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1 answer

What is the time complexity of determining maximal overlaps between bitmap images?

Given two bitmap images (two arbitrarily sized two-dimensional matrices of integer values ranging from 0 to some maximum number), I want to determine their maximum overlaps. An overlap is a relative positioning of the images (a translation of the…
reinierpost
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Algorithm to count number of overlapping rectangles of the same colour?

Say you have a grid of pixels. And there are 20 overlapping red rectangles on a blue background. I want to find an algorithm to count the minimum number of rectangles that are needed to form the image. And also the maxium extent of these…
zooby
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Matching superimposed image

We are given two grayscale images, one of which contains a large, mostly contiguous patch from the other one. The patch can be altered with noise, its levels may be stretched, etc. Here's an example We would like to determine the region of the…
Arthur B
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Finding orders in raw Echelle spectrum frame

Being new in this forum, would like to get some hints for solving the following problem. In the attached frame the short vertical line segments are emission lines. As can be clearly seen, these lines are grouped in horizontal curved bands. I need to…
noste99
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What is an algorithm to do this binary image segmantation task?

What I need to do is go from a binary image like this: to a segmented structure like this: because I have a program that operates on those separated line contours after. As you see, those contours are not perfect, they might be slightly bent but…
Konstantin H.
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What is the best way to compare two images for similarity if the brightness of the second image was changed?

I calculate similarity percent between two images. Another image is the same with changed brightness. I've already tried comparing by pixel (euclidean distance for grayscale and 0/1 values), comparing by HSV. I've tried also normalisation (pixel…
UdevV
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Good Practice : Which VAE latent variable to use in dimensionality reduction

I'm trying to use a VAE (CNN-VAE to be exact) to reduce the dimension of some images I have in a dataset. I successfully trained my VAE, but now I'm not sure of the latent variable to return. Should I use $\mu$, $\sigma^2$, or $z$ (which is sampled…
Liam F-A
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What is "energy" in computer vision

I keep seeing the term "energy" used in computer vision literature, specifically when speaking about Image Segmentation. For example on this page on Graph-Cut. I'm just wondering if someone could give me a layman's explanation of what "energies"…
Liam F-A
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Which algorithm is most suitable for comparing two images to find differences?

I have two images of two objects that are suppose to be exactly the same. I use one for reference and one as my model. I want to find an algorithm that will help me find on which areas these images vary? and return a binary map (the size of the…
Dan798
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How can you apply dynamic connectivity problem to digital photos?

I started learning DSA recently and I came across the Dynamic Connectivity Problem. One of the listed real-world applications of the Dynamic Connectivity Problem is "pixels in digital photos." How do you apply it to photos? What is it used for? I…
Srijan Mukherjee
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Would a five color display have higher image quality than an RGB display?

We have five types of photo receptors in the eyes but computer color systems just use the three red, green and blue. Three could be motivated if rod and melanopsin sensations are just linear combinations of cone sensations. Is it so or would a five…
David Jonsson
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If each pixel contains the channels for the 3 primary colours, why can a 1-bit picture only be presented in white and black?

I'm an igsce student. I'm taking computer science as an OL subject this year. Pixels are the small squares which make an image. Inside each pixel there are 3 channels: one for blue, one for green, one for red. The three primary colours from which…
Manar
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A pretrained model for mathematical equations characters detection

I am working on a project to convert equations to LaTeX code. After segmenting out the characters, I got stuck on the detection part and was looking for some pre-trained model that could detect characters of the equation for later conversion to…
Saqeeb
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2D fourier transform

I an new to image processing and I have some questions I want to understand: What is the meaning of the imaginary and real part of the 2d fourier transform? What can it tell me about the image it transformed from? For example, what can I tell about…
cbdes
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