Questions tagged [computer-vision]
Computer vision includes methods of processing, analyzing, images and high-dimensional data to form high level understanding and recognition of the scene or images.
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Seeing perfectly camouflaged objects
Consider a perfectly camouflaged object which perfectly mimicks the texture of its surrounding. One can see the object and its shape only when it moves - otherwise it is completely invisible.
When ...
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Seeing edges where there are no edges
The human eye is able to detect a square inside the square in the following two images, even though there are no obvious edges and no obvious local changes in the density of dots.
GPT4o believes to ...
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How are values assigned to pixels in hyperspectral imaging for airborne cases?
From what I know, hyperspectral images can have up to hundreds of bands. During acquisition, each pixel seems to store only one value. Later, algorithms are used to calculate the missing values across ...
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How to do spectral averaging to get satisfactory results?
I’ve been trying to implement spectral averaging as an experiment to familiarize myself better with FFTs and their uses for the past couple of days.
Until I've hit a wall when I tried to replicate the ...
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How to calculate the angular velocity of a rotating cell from a microbe video?
I have a video of Brownian motion of microbes under a microscope. From this video, I need to calculate the angular velocity of a particular prominent cell. From my understanding, what I know is that I ...
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Remove Wave Patterns from an Image Using Inpainting
I have been struggling to remove wave like patterns from my image. I tried FFT (Fourier Transform) and it wasn't good. I came across with inpainting and it looked promising but I don't know how to use ...
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How to measure the vibration of an object on a video shot at high speed camera?
I have a video fragment which I split into frames (pictures). I use them in pairs (1 frame with 2, 2 with 3, etc.) to find shifts on x and y axes (i.e. how much I need to shift 1 frame to make it like ...
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How to determine stripe width of a barcode
A barcode consists of alternating back and white stripes. Thin stripes are one "unit" wide. We'll assume fat stripes are 2 "units" wide. But how big is a "unit"?
I can't ...
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Down-scaling image at each step in LoG blob detection
I'm new to CV. I'm currently implementing the LoG blob detection. I've come across this repo on Github: BlobDetector.
The main implementation is here: Blob.
I'm confused by the down-scaling of image ...
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What is the best approach when training and HDR model with LDR data?
I am working on this project "EMLight".
Data: HDR Panoramic Photos
y: Illumination Map of the Panorama
X: HDR Croppings from the Panorama
I want to make this project work with LDR photos, ...
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"Seemingly random numbers" in sobel operator
I understand that Sobel operator approximate "changes in x-y direction" of an image using three consecutive pixels. But why are these numbers 1 2 1? Where do they come from. I tried to ...
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How do I estimate the position and orientation of two instruments looking at the same target?
Consider the following lab set-up:
Two instruments: a laser profiler (L) and a line scanner camera (C) are mounted on a rack so that they are facing a flat target downwards.
At time $t=0$, that is ...
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Why is Histogram of Oriented Gradients only 0 to 180 degrees and not 0 to 360 degrees?
Why is Histogram of Oriented Gradients only 0 to 180 degrees and not 0 to 360 degrees?
I can see in many videos that it's very common that atan which results values ...
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Does ORB-Slam3 perform better than ORB-Slam2?
I was trying to compare ORB-Slam2 performace with ORB-Slam3 performance. Consider following comparison from ORB-Slam3 paper (columns with numbers correspond to different sequences from EuRoC dataset):
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How orientation is used in FAST features in ORB?
I was going throught ORB paper. It states that it adds an efficiently computed orientation to FAST features. The description explains how it calculates
Moment of patch $$m_{pq}=\sum_{x,y}x^py^pI(x,y)$...
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