1. Digital Media Lecture 4.1: Image Encoding Practice
Georgia Gwinnett College
School of Science and Technology
Dr. Jim Rowan

2. Refer to Supplemental text:
Ways to store an image as numbers: Bitmapped Graphics  
Ways to store an image as numbers: Vector Graphics  

3. Practice Examples Each image encoded three ways: 24 bit RGB
Run Length Encoding
Table Encoding

4. Example 1 24 bit RGB 237, 132, 30 -orange 255, 255, 255 -white
120, 248, 254 -cyan
232, 68, 21 -red
0, 59, 250 -blue
67, 139, 23 -green
Example 1
24 bit RGB

5. 237, 132, 30 -orange
255, 255, 255 -white
120, 248, 254 -cyan
232, 68, 21 -red
0, 59, 250 -blue
67, 139, 23 -green
Example 1
24 bit RGB
orange | white | green | cyan |cyan | cyan | red | orange | white |
red | white | blue

6. 237, 132, 30 -orange
255, 255, 255 -white
120, 248, 254 -cyan
232, 68, 21 -red
0, 59, 250 -blue
67, 139, 23 -green
Example 1
24 bit RGB
orange | white | green | cyan |cyan | cyan | red | orange | white |
red | white | blue
237, 132, 30 | 255, 255, 255 | 67, 139, 23 | 120, 248, 254 |
120, 248, 254 | 120, 248, 254 | 232, 68, 21 | 237, 132, 30 |
255, 255, 255 | 232, 68, 21 | 255, 255, 255 | 0, 59, 250

7. 237, 132, 30 -orange
255, 255, 255 -white
120, 248, 254 -cyan
232, 68, 21 -red
0, 59, 250 -blue
67, 139, 23 -green
Example 1
24 bit RGB
orange | white | green | cyan |cyan | cyan | red | orange | white |
red | white | blue
237, 132, 30 | 255, 255, 255 | 67, 139, 23 | 120, 248, 254 |
120, 248, 254 | 120, 248, 254 | 232, 68, 21 | 237, 132, 30 |
255, 255, 255 | 232, 68, 21 | 255, 255, 255 | 0, 59, 250
36 bytes total (excluding any header)

8. Example 1 24 bit RGB Run length encoding RLE 1 byte for the count
237, 132, 30 -orange
255, 255, 255 -white
120, 248, 254 -cyan
232, 68, 21 -red
0, 59, 250 -blue
67, 139, 23 -green
Example 1
24 bit RGB
Run length encoding
RLE
1 byte for the count

9. Example 1 24 bit RGB Run length encoding RLE 1 byte for the count
237, 132, 30 -orange
255, 255, 255 -white
120, 248, 254 -cyan
232, 68, 21 -red
0, 59, 250 -blue
67, 139, 23 -green
Example 1
24 bit RGB
Run length encoding
RLE
1 byte for the count
1 orange | 1 white | 1 green | 3 cyan | 1 red | 1 orange | 1 white |
1 red | 1 white | 1 blue

10. Example 1 24 bit RGB Run length encoding RLE 1 byte for the count
237, 132, 30 -orange
255, 255, 255 -white
120, 248, 254 -cyan
232, 68, 21 -red
0, 59, 250 -blue
67, 139, 23 -green
Example 1
24 bit RGB
Run length encoding
RLE
1 byte for the count
1 orange | 1 white | 1 green | 3 cyan | 1 red | 1 orange | 1 white |
1 red | 1 white | 1 blue
1 237, 132, 30 | 1 255, 255, 255 | 1 67, 139, 23 |
3 120, 248, 254 | 1 232, 68, 21 | 1 237, 132, 30 |
1 255, 255, 255 | 1 232, 68, 21 | 1 255, 255, 255 |
1 0, 59, 250

11. Example 1 24 bit RGB Run length encoding RLE 1 byte for the count
237, 132, 30 -orange
255, 255, 255 -white
120, 248, 254 -cyan
232, 68, 21 -red
0, 59, 250 -blue
67, 139, 23 -green
Example 1
24 bit RGB
Run length encoding
RLE
1 byte for the count
1 orange | 1 white | 1 green | 3 cyan | 1 red | 1 orange | 1 white |
1 red | 1 white | 1 blue
1 237, 132, 30 | 1 255, 255, 255 | 1 67, 139, 23 |
3 120, 248, 254 | 1 232, 68, 21 | 1 237, 132, 30 |
1 255, 255, 255 | 1 232, 68, 21 | 1 255, 255, 255 |
1 0, 59, 250
40 bytes total (excluding any header)
notice that in this case, the RLE is larger than the 24 bit RGB

12. Example 1 24 bit RGB Table Encoding 237, 132, 30 -orange
255, 255, 255 -white
120, 248, 254 -cyan
232, 68, 21 -red
0, 59, 250 -blue
67, 139, 23 -green
Example 1
24 bit RGB
Table Encoding

13. Example 1 24 bit RGB Table Encoding 237, 132, 30 -orange
255, 255, 255 -white
120, 248, 254 -cyan
232, 68, 21 -red
0, 59, 250 -blue
67, 139, 23 -green
Example 1
24 bit RGB
Table Encoding
237, 132, 30 orange 000
255, 255, 255 white 001
120, 248, 254 cyan 011
232, 68, 21 red 100
0, 59, 250 blue 101
67, 139, 23 green 010

14. Example 1 24 bit RGB Table Encoding color table: 18 bytes
237, 132, 30 -orange
255, 255, 255 -white
120, 248, 254 -cyan
232, 68, 21 -red
0, 59, 250 -blue
67, 139, 23 -green
Example 1
24 bit RGB
Table Encoding
237, 132, 30 orange 000
255, 255, 255 white 001
120, 248, 254 cyan 011
232, 68, 21 red 100
0, 59, 250 blue 101
67, 139, 23 green 010
color table: 18 bytes

15. Example 1 24 bit RGB Table Encoding color table: 18 bytes
237, 132, 30 -orange
255, 255, 255 -white
120, 248, 254 -cyan
232, 68, 21 -red
0, 59, 250 -blue
67, 139, 23 -green
Example 1
24 bit RGB
Table Encoding
237, 132, 30 orange 000
255, 255, 255 white 001
120, 248, 254 cyan 011
232, 68, 21 red 100
0, 59, 250 blue 101
67, 139, 23 green 010
color table: 18 bytes

16. Example 1 24 bit RGB Table Encoding color table: 18 bytes
237, 132, 30 -orange
255, 255, 255 -white
120, 248, 254 -cyan
232, 68, 21 -red
0, 59, 250 -blue
67, 139, 23 -green
Example 1
24 bit RGB
Table Encoding
237, 132, 30 orange 000
255, 255, 255 white 001
120, 248, 254 cyan 011
232, 68, 21 red 100
0, 59, 250 blue 101
67, 139, 23 green 010
color table: 18 bytes
bitmapped portion: 36 bits/8 = 5 (4.5) bytes

17. Example 1 24 bit RGB Table Encoding color table: 18 bytes
237, 132, 30 -orange
255, 255, 255 -white
120, 248, 254 -cyan
232, 68, 21 -red
0, 59, 250 -blue
67, 139, 23 -green
Example 1
24 bit RGB
Table Encoding
237, 132, 30 orange 000
255, 255, 255 white 001
120, 248, 254 cyan 011
232, 68, 21 red 100
0, 59, 250 blue 101
67, 139, 23 green 010
color table: 18 bytes
bitmapped portion: 36 bits/8 = 5 (4.5) bytes
Total: = 23 bytes
(excluding any header)

19. Example 2 24 bit RGB 232, 68, 21 -red 255, 255, 255 -white
237, 132, 30 -orange
255, 255, 255 -white
232, 68, 21 -red
0, 59, 250 -blue

20. Example 2
24 bit RGB
237, 132, 30 -orange
255, 255, 255 -white
232, 68, 21 -red
0, 59, 250 -blue
red | orange | white | white | red | white | blue | blue |
red | white | white | white
232, 68, 21 | 237, 132, 30 | 255, 255, 255 | 255, 255, 255 |
232, 68, 21 | 255, 255, 255 | 0, 59, 250 | 0, 59, 250 |
232, 68, 21 | 255, 255, 255 | 255, 255, 255 | 255, 255, 255 |
36 bytes total (excluding any header)

21. Example 2 24 bit RGB Run length encoding RLE 1 byte for the count
237, 132, 30 -orange
255, 255, 255 -white
232, 68, 21 -red
0, 59, 250 -blue

22. Example 2 24 bit RGB Run length encoding RLE 1 byte for the count
237, 132, 30 -orange
255, 255, 255 -white
232, 68, 21 -red
0, 59, 250 -blue
1 red | 1 orange | 2 white | 1 red | 1 white | 2 blue | 1 red | 3 white
1 232, 68, 21 | 1 237, 132, 30 | 2 255, 255, 255 | 1 232, 68, 21 |
1 255, 255, 255 | 2 0, 59, 250 | 1 232, 68, 21 | 3 255, 255, 255 |
32 bytes total (excluding any header)

23. Example 2 24 bit RGB Table Encoding 232, 68, 21 -red
237, 132, 30 -orange
255, 255, 255 -white
232, 68, 21 -red
0, 59, 250 -blue

24. Example 2 24 bit RGB Table Encoding
237, 132, 30 -orange
255, 255, 255 -white
232, 68, 21 -red
0, 59, 250 -blue
255, 255, 255 white 01
237, 132, 30 orange 10
232, 68, 21 red 00
0, 59, 250 blue 11
color table: 12 bytes
bitmapped portion: 24 bits/8 = 3 bytes
Total: = 15 bytes
(excluding any header)

26. Example 3 24 bit RGB 27 bytes total (excluding any header)
237, 132, 30 -orange
255, 255, 255 -white
120, 248, 254 -cyan
orange | orange | white | orange | cyan | cyan | orange | cyan | orange
237, 132, 30 | 237, 132, 30 | 255, 255, 255 | 237, 132, 30 |
120, 248, 254 | 120, 248, 254 | 237, 132, 30 | 120, 248, 254 |
237, 132, 30
27 bytes total (excluding any header)

27. Example 3 24 bit RGB Run length encoding RLE 1 byte for the count
237, 132, 30 -orange
255, 255, 255 -white
120, 248, 254 -cyan
2 orange | 1 white | 1 orange | 2 cyan | 1 orange | 1 cyan | 1 orange
2 237, 132, 30 | 1 255, 255, 255 | 1 237, 132, 30 | 2 120, 248, 254 |
1 237, 132, 30 | 1 120, 248, 254 | 1 237, 132, 30
28 bytes total (excluding any header)

28. Example 3 24 bit RGB Table Encoding Total: 9 + 3 = 12 bytes
237, 132, 30 -orange
255, 255, 255 -white
120, 248, 254 -cyan
237, 132, 30 orange 00
255, 255, 255 white 01
color table: 9 bytes
120, 248, 254 cyan 10
bitmapped portion: 18 bits / 8 = 3 bytes
Total: = 12 bytes
(excluding any header)

29. Another table encoding example

30. Example 4 24 bit RGB Table Encoding color table: 18 bytes
237, 132, 30 -orange
Example 4
24 bit RGB
Table Encoding
255, 255, 255 -white
67, 139, 23 -green
120, 248, 254 -cyan
232, 68, 21 -red
0, 59, 250 -blue
237, 132, 30 orange 000
255, 255, 255 white 001
120, 248, 254 cyan 011
232, 68, 21 red 100
0, 59, 250 blue 101
67, 139, 23 green 010
color table: 18 bytes
bitmapped portion: 48 bits/8 = 6 bytes
Total: = 24 bytes
(excluding any header)

31. Additional practice images