Search Results for: color name

If we want to process images the first thing we need to do is to read an image into MATLAB as a variable in the workspace. What kind of variable is an image? How can we see the image inside a variable? How do we refer to to individual pixels within an image.

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.

We use MATLAB and some Toolbox functions to model the spectrum of a realistic light source, its modification after reflection from a colored object and the response of the cone cells to form a tristimulus response.