Reading an image from a file is fairly straightforward in OpenCV-Python. But a lot of times, we would like to read an image from a URL and process it in OpenCV. One way to do it is to download the image, save it as a jpeg file, and then read it in OpenCV. But that's … Continue reading How To Read An Image From A URL In OpenCV-Python
Category: Image Processing
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?
Understanding Gabor Filters
In the field of image processing, filters play an extremely important role. If you don't know what a filter is, you may quickly want to read the wiki article and come back. Otherwise, this post will not make much sense to you. All image processing operations can be viewed as applying a series of filters … Continue reading Understanding Gabor Filters
Reading JPEG Into A Byte Array
Let's say you are working with images for your project. A lot of times, when you have to work across multiple platforms, the encoding doesn't remain the same. In these scenarios, you cannot process images directly by treating them like 2D matrices. One of the most common image formats you will comes across is JPEG. … Continue reading Reading JPEG Into A Byte Array
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
Perpetual Enigma 