1. Digital Image Processing Homework 3
Jheng-Ping Lin
Visual Communications Lab
Department of Communication Engineering
National Central University
Jhongli,Taiwan
November 18, 2007

2. Create this Picture Using HIS Color Space

3. Review HIS Color Space(1/3)

4. Review HIS Color Space(2/3)
Saturation
[0~1]
Intensity
[0~1]
Hue
[0∘~360∘]

5. Hue(I:1. 0, S: 1.0) H: 0∘ H: 45∘ H: 90∘ H: 135∘ H: 180∘ H: 225∘

6. Intensity(H: 0˚, S: 1.0)
I: 1.0
I: 0.75
I: 0.5
I: 0.25

7. Saturation(H: 0˚, I: 1.0)
S: 1.0
S: 0.75
S: 0.50
S: 0.25

8. Review HIS Color Space(3/3)

9. Converting Colors form HIS to RGB (1/4)
If (0∘≦ H < 120∘)
B = I*( 1 - S ) R=
G= 3*I-B-R
H: Hue
S: Saturation
I:Intensity

10. Converting Colors form HIS to RGB (2/4)
If (120∘≦ H < 240∘)
H=H-120∘
R = I*( 1 - S ) G=
B= 3*I-G-R

11. Converting Colors form HIS to RGB (3/4)
If (240∘≦ H < 360∘)
H=H-240∘
G = I*( 1 - S ) B=
R= 3*I-B-G

12. Converting Colors form HIS to RGB (4/4)
New R=max(min(R,1),0)*255
New G=max(min(G,1),0)*255
New B=max(min(B,1),0)*255

13. Homework Assignment
512 pixels
Intensity: 0.5
512 pixels

14. Hint
512 pixels
(X,Y)
512 pixels
Hue

15. Deadline Demo : 2008/12/3, 8:00~9:00 pm Report : 2008/12/3, 6:00 pm
Applications of HIS color space in image or video processing.

16. References
Rafael C. Gonzalez, Richard E. Woods, “Digital Image Processing 3rd”, pp , August, 2008.