Incandescent light sources emit a lot of infrared radiation which we cannot see but can sense as heat. Non-incandescent sources such as fluorescent lights, cathode ray tubes and LEDs have quite different spectrums. When light travels through an absorbing medium, such as the atmosphere or water, different wavelengths are absorbed differently and this alters its […]
Search Results for: color temperature
The light we see is a mixture of different wavelengths in the visible region of the electromagnetic spectrum. The most common source of light is incandescence from a very hot body such as our sun or the filament of an old-fashioned light bulb. The spectrum, the amount of energy as a function wavelength, follows Planck’s […]
We can create most colors by a suitable mixture of three primary colored light sources, typically red, green and blue. Let’s look at how color mixing works.
Color is a very important concept for people. We have lots of words to describe colors and we even associate them with emotions.
Let’s learn how to import a color image into MATLAB and see how the data is organized as a matrix with three dimensions.
As the illumination level changes so do the red, green and blue tristimulus values, but they are linearly related. We can separate brightness from chromaticity which is a two dimensional representation of color. We discuss briefly the effect of gamma encoding on the color reproduction process.
Humans are trichromats which means that our eyes have three types of cone cells which are sensitive to different parts of the spectrum: red, green and blue light. They perform a non-unique mapping from an arbitrary spectrum of light into three signals which are known as a tristimulus which we perceive as a particular color. […]
A color camera has many similarities to the human eye. Instead of three types of cone cells a uniform silicon sensor uses a pattern of three color filters known as a Bayer filter.
Color is an important characteristic of objects in our world and useful in distinguishing between objects. Let’s talk about where color comes from and how we can describe it.
We use MATLAB and some Toolbox functions to find tomatoes on a bush. We convert the color image to chromaticity coordinates, select the pixels that belong to the tomatoes and the perform blob analysis to find the location of the tomatoes.