What is Images: Definition and 388 Discussions

An image (from Latin: imago) is an artifact that depicts visual perception, such as a photograph or other two-dimensional picture, that resembles a subject—usually a physical object—and thus provides a depiction of it. In the context of signal processing, an image is a distributed amplitude of color(s). A pictorial script is a writing system that employs images as symbols for various semantic entities, rather than the abstract signs used by alphabets.

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  1. L

    Method of images with dielectric

    Hi everyone I have an understanding problem concerning the method of images method Homework Statement Jackson uses this kind of problem in his textbook but I don't understand it. We have a charge q on the z axis at distance d. the dielectric constant is e1 when z>=0 and e2 when z<0. Now...
  2. A

    Mirrors reflecting images infinitely

    Hi Everyone, This is a physics problem but also an everyday home one I'm trying to resolve. In our bathroom, we have two mirrors on opposite walls (parallel walls)... because of this, they reflect images of the person between them infinitely many times - it's actually quite a bit nauseating...
  3. S

    Shooting images through window pane glass

    For a simple starter, I'm curious what the transparency of pane glass is. Moreover, we have a domed observatory and one of the two shutters (lower) has a common window pane about 3' on a side. In fact, there are three elements of the shutter area; upper, lower, and a wind screen (below the...
  4. K

    Convex Mirror & Virtual images

    1. A spherical mirror is used to form an image 5 times as tall as an object, on a screen positioned 5.0m from the mirror. a) Describe the type of mirror required b) Where should the mirror be positioned relative to the object 2. M = (Di)/(Do) & 1/(Di) + 1/(Do) = 1/(F) 3. I have...
  5. S

    Interpreting Gravitational Lensing Images?

    I recently stumbled on the topic of gravitational lensing (GL) via an article in the Nov. 2001 issue of Sci Am magazine. I've since Googled the topic, and slightly enhanced my understanding of it. So far none of what I've read seems to interpret the resulting images. That is, they briefly...
  6. D

    Method of Images: Grounded Conducting Sphere

    Homework Statement A point charge +q is situated a distance a from the center of a grounded conducting sphere of radius R. Find the induced surface charge on the sphere as a function of θ. Integrate this to get the total induced charge.Homework Equations σ=-εo*∂V/∂r Q=∫σ daThe Attempt at a...
  7. fluidistic

    Going through Jackson's book (electrodynamics, method of images)

    Homework Statement I would like to 1)Find the electric field in all the space in the following set up: There's an electric charge q in a region with dielectric constant ##\varepsilon _1## which is at a distance d from a plane that separates the space into 2 regions, namely the one of the...
  8. C

    Why are images not appearing on my browser?

    I am using opera as my browser and have windows xp. I can see text on Internet pages but no pictures on my page. I tried to find Internet tools but I couldn't find it. What should I do. Any help will be much appreciated.
  9. B

    Images of electron orbitals for H2, He, Li and Li2?

    Is there some resource on the net where I can find images of electron orbitals for dihydrogen (H2), helium (He), lithium (Li) and dilithium (Li2)? Alternatively if there is some software that can produce such images, that would be good too.
  10. W

    Method of images to find potential near a grounded plane

    Homework Statement Have my E&M final tomorrow. Trying to work old test questions. Please check my answer for this question. Uniformly charged sphere of charge Q and radius R, center is a distance d above a grounded plane.Homework Equations V(r) in the interior of a sphere is given in the...
  11. K

    Is a Flat Mirror Capable of Producing a Real Image?

    I am struggling on one concept that I can't find when doing a thorough search. System: You have a projector (known to project real images onto a screen). The projector expands light with a lens, the light propagates to a flat mirror on a wall and reflects onto a screen.Conclusion: Although the...
  12. R

    Mirror & Image Physics: Speed of Truck Image to Driver

    Homework Statement The rear view mirror of a car is a plane mirror. A driver is reversing his car at the speed of 2 m/s. The driver sees in his rear view mirror the image of a truck parked behind hid car. The speed at which the image of the truck appears to approach the driver will be? The...
  13. M

    Optics,how many images will the object form?

    optics,how many images will the object form? Homework Statement the lens shown in figure 19.16(http://img705.imageshack.us/img705/5066/figure1916.png made of two different materials . a point object is placed on the axis...how many images will the object form? Homework Equations 1/f...
  14. O

    Apparent size of comets in images from the SOHO satellite

    I've gotten into an amusing discussion with another individual on the topic of the apparent size of comets as seen in SOHO satellite images of Sungrazing or Sun-impacting comets. I won't go into the crackpot conspiracy theories I've heard, but will instead ask: why do these tiny comets appear so...
  15. T

    Calculating Electric Field b/w Grounded Conductors w/ Method of Images

    1. Homework Statement Two semi-infinite grounded conductive planes meet at right angles. In the region b/w the conductors, there is the plane with angle 45° having surface charge density σ. Using the method of images, find the field distribution in this region. (There is a picture included...
  16. N

    Method of Images- Force on Plane

    Homework Statement What is the force on an infinite conducting plane due to two point charges: a +2q located at a height 4h above the plane and a -q charge located at a height 2h above the plane, directly beneath the other point charge. Homework Equations The Attempt at a Solution...
  17. PhizKid

    How to insert images into TeXnicCenter (DVI)

    I am trying to using this line: \includegraphics{C:/Users/PhizKid/Desktop/Untitled.jpg} But there is no image showing up when I view the DVI file. What am I doing wrong? (I have \usepackage{graphicx} somewhere at the top) nvm, I got it
  18. tomwilliam2

    Electrostatic potential using method of images

    Homework Statement There is a charge q, at a distance d from an infinite conducting plane (z=0). Determine the electrostatic potential drop between the z=0 and z=d. Homework Equations Ohm's Law DeltaV=-integral (E.dl) The Attempt at a Solution I know how to do this problem...
  19. P

    Why does the size of an image in a plane mirror not change when drawn on paper?

    When an object is moved away from a plane mirror, its size decrease when seen in the mirror. But, when we draw image on paper for an object in different positions in a plane mirror, the size of the image doesn't seem to change. Why? Will the size change or not?
  20. 0

    Visualizing Real Images and Multiple Reflections: Questions Answered

    Hi, I realize that this might be kind of a silly question, but I am in a physics class currently and I'm having the hardest time visualizing what exactly is happening when a 'real image' is formed on the same side as the object (as in the case of an object emitting light on the concave side of...
  21. S

    Real and virtual images from mirrors

    Homework Statement When we look into a mirror, the image formed in virtual as it cannot be captured on a screen. However, If we shine a torchlight at an angle then the beam of light will reflect and form on a screen. But how are we so different from the torchlight's light? Since we simply...
  22. F

    Wavelet transform for images cannot interpret it correctly

    Wavelet transform for images...cannot interpret it correctly... Hello Forum, The discrete wavelet transform and the continuous wavelet transform are two different beasts. When we take the DWT of an image, we get a bunch of subimages that are different in size. Each subimage is like a...
  23. C

    Lateral Inversion of Images Formed by Convex & Concave Lenses

    Lens problem! Hi guys, When an object is placed in front of a convex lens ( not between Focus and optical centre ), the image formed on the other side should be inverted and real. My question is, with the mentioned placement of the object, will the image be laterally inverted? Further more...
  24. J

    Images formed by cylindrical lens

    Cylindrical lenses focus light rays onto a line instead of a point. Is that means several images will be formed from a point object aftering passing through the lens? (please see the attached files 1 and 2) If I am correct, can anyone explain to me,when you add water to a tall water...
  25. P

    Need specific Hubble images. Archive does not have them.

    I'm doing a summer internship and my supervisor is currently away and uncontactable. He left me details of certain Hubble images to download and analyse asking for HST images of M31 with coordinates 00:42:52.534 +41:18:54.17 on 2006-07-15 and 2007-01-12. (YYYY-MM-DD) The problem is that...
  26. K

    MATLAB Matlab- Function for select and use images

    Hi! I'm writing you to ask about a question, to see if anyone knows how to solve it. I'm doing an interpolation process and I would add a function to a Matlab code that would select and use two dates up and down in the process for a selected image (I opened it before with the function...
  27. F

    Images of the Universe: Lasting Through Time

    We "see" distant objects as they were , sometimes, very, very, long time ago. I assume these images are all in the fleeting / transient - for us - category. What is it in their nature that makes them last - for us, and, potentially, other observers, to "see" them. In our world, all images...
  28. Y

    Java [Java] How do I save a bunch of images as one?

    I have a program where the user selects image icons in one JPanel and can place them in another JPanel. The program saves the position of the icons as an array of integers where each integer represents the different icons. I need to also save the final result as a .gif image because otherwise it...
  29. N

    Images in a diverging lens are always virtual. when an objectis placed

    images in a diverging lens are always virtual. when an objectis placed betweenthe focus and optical centre of a converging lens, the image is also virtual. what are the differences between these virtual images? explain by studying the 4 characteristics of each image. i have no idea of...
  30. G

    Using images off the web for a report?

    What's the general rule of thumb for plucking an image off the web and using it in your report? Is this allowed as long as you cite the webpage or do you have to have very explicit permission from the website owner? I don't know what's right and wrong here since I just want to use an image for...
  31. B

    LaTeX How can I add images and nomenclature in my LaTeX thesis report?

    Hello PF, I am using MiKTex and TeXnicCenter for writing my Thesis Report. I want to add images (.jpg or .eps format) into the report. The last one I tried was, \usepackage{graphicx} \begin{figure} \includegraphics[scale=0.40]{121127332} \end{figure} What I get is just a empty...
  32. A

    Joint probability distribution of two images

    I'm posting this here, as i feel it's more probability-related than image processing. I'm reading this lecture pdf. At end of page 1 , beginning of page 2 it says: Is this a bit vague, or am i missing something? Since we are calculating frequency of the value a in the pixels of image A, when...
  33. A

    Explaining Why Total Charge Induced = -q for Image Problem

    Consider the classic image problem with a conducting plane and a point charge. After finding out the charge density on the plane we integrate to find out the total charge induced. It comes out to be "-q",where q is the charge outside- My book says "It comes out to be -q, as you can convince...
  34. J

    Asking for your sources of images of the whole earth.

    Hello there, I am a Norwegian image maker. Unfortunately, I find discrepancies between photographs of the Earth from the Apollo missions (such as the blue marble) and images from the space shuttle and orbiters, which I cannot explain. They vary from the appearance of the atmospheric scattering...
  35. A

    Multiple images in gravitaional lensing

    On the subject of gravitational lensing there seems to be two rather different phenomena. The "arc" phenomena seems rather plausible to me, if light is affected by gravity which is natural then there should be able to get that kind of behaviour. But the multiple imaging stuff, seems rather...
  36. N

    Reconstruction of a 3D image from layered 2D images

    I am currently looking at constructing a model of a 3D printed item based on a sequence of images of each layer of the print. At the moment the sequence of images are transformed to black / white and run through a Moore Neighborhood algorithm and then a voxel representation of the printed...
  37. Z

    Exploring the World of Virtual Images

    Virtual image?? Nvm I got it. Thank you anyways virtual image is not the actual distance kk.
  38. Angelos K

    Multiple images in gravitational lensing

    Dear all, so far I have only studied weak lensing. Therefore I understand little about multiple images.The light paths, by Fermat's principle, have to correspond to stationary points of the (proper) time delay. Minima, maxima saddle points. Basics are nicely reviewed here [p.14]...
  39. S

    Number of images formed by two concave lens, one displaced from optical axis

    Homework Statement A biconvex symmetrical lens is cut in two halves and placed as shown in figure. if a point object is placed in the left how many images will be formed options - (a) Two images (b) Three images Homework Equations The Attempt at a Solution As I...
  40. H

    Linear Algebra Question, Vector Images

    Homework Statement Let T:R^4->R^3 be the linear transformation de fined by T( x1, x2,x3,x4) = 2(x1) - 4(x3) (x2) -(x3)+3(x4) (x1)+(x2)-3(x3)+2(x4) Find the vector from the domain, Xd, which gives the image Xr = (2 1 1) in the range of T The Attempt at a Solution I don't need...
  41. C

    Projection of meteorology radar images onto a sphere

    Hello everybody, I am working on a project for merging the images of multiple meteorology radars covering a large area. I would like to project each of the images onto a spherical surface and merge them. Do you know if there is a piece of software that can help me with that? I can develop in...
  42. L

    Do we see multiple images in mirror?

    When we look at a mirror we see our image but the light that reaches our eyes also reflects off our bodies back to the mirror again and back to our eyes. Do we see multiple images of our self but somehow ignore all but the primary reflection?
  43. M

    Solving Image Problems with Orthonormal Systems - M. Next

    Hello :) I would be very grateful if I get through with this bugging idea. When I started reading about it, the first example was: A point charge in front of a finite plane conductor. And I understood after some mathematical and geometrical procedure how it is okay to replace the finite plane...
  44. R

    Can We Still Receive Images from Voyager Probes?

    Hi. A friend of mine, knowing about a probe (actually, 2) going out from the solar system, asked to me if we can still receive images from them. I searched for these images on the web, but i did not found them. Anyone can suggest to me a link? Thanks :)
  45. A

    Optics: images of object in half a spherical mirror

    Hi, http://imageshack.us/photo/my-images/141/optica.png/ The sphere in the picture is made of glass with n = 1.60. The curved side of this sphere is a mirror. The question is why we see two images of the black dot. Homework Equations Snells law? The Attempt at a Solution One...
  46. K

    Question on Optics, finding images of a pin using a concave mirror

    A pin AB, 1cm long, is placed at an angle to the principal axis in front of a concave mirror, of focal length 5cm. Point B lies on the principal axis at a distance of 4 cm. Point A is such that the angle ABP is 60°, where P, the pole, is the point where the principal axis intersects the mirror...
  47. H

    Real Analysis: Worked Examples and Graphical Representations

    Does anyone know of a good resource for these types of problems? I took an Intro to Real Analysis class as an undergrad and didn't do so well in it, but now I am working back through the book, and it is making A LOT more sense than it did back then. However, I was looking for some worked...
  48. J

    Optics: when are images virtual and when are they real?

    sorry, no specific homework question, although it is related to my homework in general. I don't understand what makes an image real or virtual. thanks for the help :) joe
  49. T

    Medical How logisticlly are imaginary images formed in the brain?

    Is it a collage of interacting nuerons and the cohesive accumulation of information? Or something else, don't tell me its dependent on quantum proporties?
  50. R

    Charge on a grounded conductor w/ method of images

    Why is it that whenever the method of images is used to solve for the induced charge on a grounded conductor in the presence of a point charge, the total charge is just the same as the image charge?
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