A truecolor image is an image in which each pixel is specified by three values — one each for the red, blue, and green components of the pixel's color. MATLAB® store truecolor images as an m-by-n-by-3 data array that defines red, green, and blue color components for each individual pixel. Truecolor images do not use a colormap. The color of each pixel is determined by the combination of the red, green, and blue intensities stored in each color plane at the pixel's location.
Graphics file formats store truecolor images as 24-bit images, where the red, green, and blue components are 8 bits each. This yields a potential of 16 million colors. The precision with which a real-life image can be replicated has led to the commonly used term truecolor image.
A truecolor array can be of class
double. In a truecolor array of
double, each color component is a
value between 0 and 1. A pixel whose color components are (0,0,0) is displayed as black,
and a pixel whose color components are (1,1,1) is displayed as white. The three color
components for each pixel are stored along the third dimension of the data array. For
example, the red, green, and blue color components of the pixel (10,5) are stored in
The following figure depicts a truecolor image of class
The Color Planes of a Truecolor Image
To determine the color of the pixel at (2,3), you would look at the RGB triplet stored
in (2,3,1:3). Suppose (2,3,1) contains the value
0.1608, and (2,3,3) contains
color for the pixel at (2,3) is
0.5176 0.1608 0.0627