Questions tagged [imaging]
The imaging tag has no usage guidance.
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Super resolution with STED microscopy and evanescent waves?
Consider the angular spectrum method, given a field $U$ with a wavelength $\lambda$ we can decompose it with Fourier transform.
\begin{equation}
U(x, y,0) = \int \int {\tilde{U}_0(f_x,f_y)} e^{2 \pi ...
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Connection between the Modulation Transfer Function (MTF) and Line Spread Function (LSF) in "Hecht - Optics, 5th ed"
I try to understand the derivation of the connection of the MTF and the LSF and found a derivation in the Book "Optics" by Eugene Hecht (5th edition), chapter 11, section 11.3.6.
However, ...
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What is the benefit of using entangled photons for ghost imaging compared to just spatial correlated photons?
I am planning to work in quantum ghost imaging. I will be using a type 2 entangled spdc source which is already there in the lab. I need to know what will be the effect of using polarization entangled,...
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My phone sees the NIR from a TV remote. Why does it not see the NIR in rainbows?
My Pixel phone's camera shows the IR light from the LED of a TV remote as a magenta/lavender color. That wavelength is likely around 940 nm.
Now, when I take a picture of a rainbow in the sky, it does ...
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What exactly is deconvolution doing?
The widely recognized theory for the detected image in microscope (I believe) is calculated by taking the convolution of the object and a point spread function (PSF). Deconvolution tries to reverse ...
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Why are CT scans much smaller than the raw data?
I'm not too familiar with CT, but I worked with medical CT images long ago, and recall that the raw data, recorded by the scanner was way bigger than the 3D image itself (Both were 16-bit TIFF files, ...
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Is it posisble to have multiple obejcts in focus provided that parallel ligthrays pass through them? [closed]
I have the following setup, with a light source, 4 mirrors (two concave and two flat) and a 200mm lens, plus a divergent lens.
In the parallel section of the flow, I have a translucent background (in ...
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Calculating the power received by a pixel from a set of rays
I've written a path tracer and am now working on implementing a physically accurate way of simulating the actual sensor response for a given wavelength$^*$, given an exposure time, aperture size, ...
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4f Imaging System with cylindrical lenses
I have seen an imaging system (4f) which uses two cylindrical lenses in a 4f configuration, but with an extra cylindrical lens at the fourier plane. How does this work?
Edit: Posting an image of the ...
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Does the substage condenser numerical aperture cap total resolution of an imaging system?
Amongst formulas to estimate the theoretical resolution of a transmitted light microscope, I often see:
$$
\delta = \frac{1.22\lambda}{NA_{obj} + NA_{cond}}
$$
Where $NA_{cond}$ is the numerical ...
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Can neutral density filters be substituted by other parameters of the imaging system in any context?
One of illuminators in my imaging system has a built-in neutral density filter. I am considering removing it and changing the exposure time of the imaging system's camera to compensate for the ...
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What is the Point Spread Function of a pinhole camera?
Is the geometric spread of a pinhole camera a uniform blur convolution?
Pinhole cameras have blur due to a. wave effects (diffraction) and b. ray effects (geometric properties). This question ignores ...
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When building an optical system, how can I increase the size of the useful image?
I am trying to put together a system of lenses that has a probe with a 2 mm diameter. The system has a probe with an objective and a relay and a set of lenses with a larger diameter that function as a ...
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Is Terahertz SAR imaging of Earth possible?
The Terahertz band is at the Wavelength range of 1 mm to 100 μm, which is very good for synthetic aperture radar aka SAR since the shorter the wavelength the better angular resolution you get. ...
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How the resolution of an image change when it is out of focus?
do you know if does exist a relationship between resolution and out of focus imaging?
For example given a lens, an aperture and a distance d. How can I calculate how much out of focus is an object ...
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Can radar detect electrical fields?
Can we create a radar image of electrical fields, or this is even possible?
Do we need a detector opposite the emitter or does reflection work?
(see figure.1)
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So what do we really see in the image of the black hole?
I have already read this question - Orange ring in a black hole image
And also have seen several videos about it (Specificaly one from Veritasium -https://www.youtube.com/watch?v=zUyH3XhpLTo&...
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How does MRI distinguish information between in-plane localization and slice selection, despite both using frequency encoding?
A MRI machine can generate 3D image of a human brain. A 3D image have three axis x (horizontal), y (vertical) and z (head-foot). First, a slice along z were selected using frequency encoding. Then, ...
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Temporal vs Spatial Contrast in Speckle Contrast Imaging
I have been reading about Speckle Contrast Imaging recently. Its quite an interesting topic given that it should be possible with relatively inexpensive equipment. The basic premise from what I ...
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Why bi-telecentric lens works with a finite focal length while it should be afocal system？
I bought a bi-telecentric lens for experiment. From all I've learned before, it accepts only axis-parelle incoming beams and exits the same parelle light, so it should be an afocal system with ...
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Entaglement and causality violation. Devices that detect pure states
I have not seen a similar question to mine on the site. Please forgive me if there is any.
When I studied quantum mechanics and the entanglement phenomenon, I was told that, although when one wave ...
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How does x-ray attenuation compare to sound wave attenuation?
When it comes to medical imaging (x-ray and ultrasound specifically) there seems to be a difference between the attenuation of sound and x-rays.
What I am gathering is as follows:
When it comes to x-...
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How pinhole camera works? [closed]
What is the working principle of pinhole camera? What is the function of translucent screen in the camera? Now, if we look behind the translucent screen, what do we actually see: the image formed on ...
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Simulate a camera PSF?
Say I have a $3D$ object stored as a $3D$ $\texttt{NumPy}$ array in python. I want to view this $3D$ object as a camera would give: a particular aperture, focal length, etc. My understanding is I can ...
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What is the technology that uses a rectangular mask to do high focus imaging?
There is a newly developed technology that involves using a specialized mask to resolve images without the use of a lens. The technology potentially allows the imaging system to avoid limitations ...
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Is it possible to take long-distance X-ray images at a high resolution in Earth's atmosphere?
It's my understanding that different wavelengths of EM radiation are affected by scattering and attenuation to varying degrees. Would a camera using only X-rays be able to take a picture of something ...
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Why is the Point Spread Function of a diffraction limited lens the Fourier transform of the Aperture Function?
I understand that only part of the spherical wave emerging from a point source in the object plane can be captured by the lens and so only a partial converging wave creates the image as shown on ...
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How do I apply Zernike coefficients to a wavefront?
I have been using the textbook "Numerical Simulation of Optical Wave Propagation with Examples in Matlab" (pdf available online: https://www.academia.edu/42684537/...
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How can the Fourier delta function produce different matrices in single-pixel imaging?
The pattern in the masks used for single-pixel imaging are created applying equation $(1)$,
$$P_\phi (x,y) = \frac{1}{2} \left[ 1 +| F^{-1} \{\delta_H (u,v) e^{i\phi}\}|\right], \tag{1}$$
in which the ...
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Is it possible to get a resolution that is better than what is given by the Rayleigh criterion?
I remember reading recently that it is possible to unblur a face that has been blurred by using a computer to process multiple images of the blurred face from different angles. This got me thinking, ...
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Does it makes sense to interpret the Point Spread Function as a volumetric density of energy?
The Point Spread Function (PSF) of an imaging system is its impulse response. Therefore
$$ I(x,y,z) = \left[O \star PSF\right](x,y,z) $$
where $I$ is the image, $O$ is the object, and $\star$ is the ...
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How does a transformation domain differ from a spatial domain?
In the context of single-pixel imaging, the following statement is given:
"Global transformation has a property that each point (coefficient) in the transformation domain
is a weighted sum of all ...
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Why does CW imaging not provide the same data as Pulsed imaging?
"Unlike pulsed THz imaging, the CW imaging (...) only yields intensity data and does not provide any depth, frequency-domain or time-domain information (...)." [1]
Why does a pulsed signal ...
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What's limiting the field of view of a lens
An ideal lens with finite aperture leads to the formation of an image in the image plane as
\begin{equation}g(x, y) = \int \text{psf}(x/\lambda d - x', y/\lambda d -y') f(x', y') dx'dy',\end{equation} ...
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Glow around objects in AFM image (amplitude modulation mode)
I have made an AFM scan (Amplitude modulation mode) of a sample consisting of polyethylene in a matrix of polystyrene. I have tried to figure out why there appears a 'glow' around the domes of ...
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Imaging aberration
Qs: Doesn't a curved side lens produce less aberration than a flat lens in general because the overall angle of deviation is smaller in the curved lens?
Consider the following experimental results ...
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Why does MRI (Magnetic Resonance Imaging) have high contrast and spatial resolution albeit having lower frequency and higher wavelength?
So we've been discussing this in the classroom and I really can't say if my answer to this question is correct since there could be various answers to this.
I know that to have a high-resolution image,...
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How to feel energy so I can imagine it? [duplicate]
Please tell me what is energy in reality and how can I imagine it . Please don't rearrange the question . Thanks
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Implement EPR Imaging deconvolution
I have bruker's EPRI data and I want to deconvolute it.
I read some article, that says
$$
f(r) = x(r) \circledast g(r) \\
F(ω) = X(ω) \times G(ω) \\
X(ω) = \frac{F(ω)}{G(ω)}
$$
$f(r)$: imaging spectre,...
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In Quantum imaging with undetected photons, why is the idler photon sent through a second non-linear crystal if it is then discarded?
I've been reading up on quantum ghost imaging and other similar approaches. In particular, I'm reading a paper Quantum Imaging with Undetected Photons by Gabriela B. Lemos et al and trying to ...
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Could we take an image of a fundamental particle?
I would like to know is there any physical limitations that prevent us from imaging a fundamental particle in someway? The Planck length gives us a limit to measurability wrt distance, is this the ...
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Understanding the spatial resolution of a imaging sensor, should it evenly divide the overall image resolution?
I am reviewing the Landsat 1 satellite, specifically its Multispectral Scanner (MSS) imaging system. The system had the following specifications
...
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Should we trust quantum mechanics for working of the mirrors?
In this video, it is explained that it is not necessary that photons obey the laws of reflection and each photon can take any possible path to reach the so-called black hole receiver and all the paths ...
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Determining the size of a light source
I have an incoherent light source that is of unknown size, and I was wondering about the possible methods to measure its size. The issue is that I am expecting it to be very small (few micrometers), ...
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Imaging with A Fresnel Lens
I am in need of an optics expert on imaging, and in particular a fresnel lens is being used as for an imaging device. From my understanding a condenser lens can be considered equivalent to a plano-...
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Imaging with two lenses: what if the distance between the lenses is not $2f$?
A $4F$-configuration is usually utilized for imaging with $2$ lenses. An object is placed in the focus of the first lens ($f_{1}$), then the second lens is located at a distance $f_{1}+f_{2}$ from the ...
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When given magnification alone,for an upright, virtual image, with convex lens, how can I find object distance [closed]
Formula involved in such calculations, similar examples, link associated with d question
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Derivation of image displacement by prism
dWhen white light go through a prism it splits to the rainbow colors. I know a formula to calculate the displacement of an image when light goes through a prism, However, it is not wavelength ...
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Plausibility of detecting viruses using optical spectra [closed]
Ok, this is a huge long shot, and I also apologise if this is a poor question (I'm a newbie here...). This doesn't seem to me a strictly perfect fit for Chemistry.SE, Biology.SE, or Photography.SE ...
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How to interpret the cross-spectral density of an incoherent field
I have been given a definition of the cross spectral density of a completely incoherent field:
$$W(x_1,x_2)=S_0\delta(x_1-x_2)$$
How do I interpret this? As I understand it, this means that there ...
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