People in computer vision and graphics deal with homogeneous coordinates on a very regular basis. They are actually a nice extension of standard three dimensional vectors and allow us to simplify various transforms and their computations. When I say "transformations", I am talking about all those special effects on the screen, and the corresponding movements … Continue reading The Concept Of Homogeneous Coordinates
Category: Camera
Understanding Camera Calibration
Cameras have been around for a long time now. When cameras were first introduced, they were expensive and you needed a good amount of money to own one. However, people then came up with pinhole cameras in the late 20th century. These cameras were inexpensive and they became a common occurrence in our everyday life. … Continue reading Understanding Camera Calibration
What Is Gamma Correction?
Gamma correction is an integral part of all the digital imaging systems, but a lot of people don't know about it! It is an essential part of all the imaging devices like cameras, camcorders, monitors, video players, etc. It basically defines the relationship between a pixel's numerical value and its actual luminance. Now wait a … Continue reading What Is Gamma Correction?
Histogram Equalization Of RGB Images
When you capture an image using your phone in the evening without flash, do you see how the image is a bit on the darker side? When you take an image with too many lights around you, the images becomes a bit too bright. Neither of the two situations gives us a good quality picture. … Continue reading Histogram Equalization Of RGB Images
Purkinje Effect
Ever wondered why the colors seem to change at night? For example, if you look at an air painting, you can see how the colors of objects look radically different in very low light just before dawn or dusk. Consider a red rose, for instance. We know that the flower's petals are bright red against … Continue reading Purkinje Effect
Kruithof Curve
This is more of a continuation of my blog post on color temperature. Back when fluorescent light sources first came up, they changed the way humans thought about light and color rendering. A scientist named Arie Andries Kruithof performed some experiments on how the human eye relates the amount of light in a given time … Continue reading Kruithof Curve
What Is Color Temperature?
Wait a minute, isn't "temperature" associated with weather? How can color have temperature? The thing is that color temperature is actually a characteristic of visible light that has several important applications in photography, publishing, and many other fields. We actually see and feel it all the time, it's just that we don't realize that we … Continue reading What Is Color Temperature?
Pixelation
Pixelation is the display of a digitized image where the individual pixels are easily visible to a viewer. This can happen unintentionally when a low-resolution image designed for an ordinary computer display is projected on a large screen. In this situation, each pixel becomes separately viewable. It's not pretty! Pixelation is also sometimes used to … Continue reading Pixelation
Panoramic Images
Consider a situation where you are standing on top of a mountain or some other beautiful natural scenery. You are enjoying a beautiful view that seems to span from far left to far right and you want to take a nice picture of the whole thing. Your camera allows you to capture only a limited … Continue reading Panoramic Images
Connecting With Kinect
If you haven't experienced Kinect yet, do yourself a favor and just go do it! For people who have just landed on earth, Kinect is a motion sensing device for Microsoft XBox 360 video game console. You can check out the video here. Instead of using buttons or controllers to play video games, this device enables … Continue reading Connecting With Kinect
Perpetual Enigma 