Image Processing Basics - Digital Signal Processing: Fundamentals and Applications - page 724

Image pseudo-color
generation for detection

Pseudo-color generation

1) Gray to Red transformation
using a sine function.
2) Gray to Green transformation
using a sine function.
3) Gray to Blue transformation
using a sine function.

Note the phases are different

R

0 2

Indexed color image
1) Pixel value is an index; there are
256 indices.
2) Each index points to a color map
entry with three values: Red, Green
and Blue.

G

0 255

B

255

0 100 110

0
1

R GB

Pixel value
between 100 and
110 will look like
green

1

255

[X, map]=imread('file name','format');

X=ind2rgb(X,map)

[X,map]=rgb2ind(X,256)

X=ind2gray(X,map)

Grayscale image
1) Each pixel has a value with
a range of 0 to 255.

RGB color image
1) Each pixel has three values:
Red, Green, and Blue.
2) There are red image, blue
image, and green image
components.

X=rgb2gray(X)

R G B

X=imread('file name','format');

FIGURE 14.34