1. DIP 9 65
Original
210
Eye
Zoomed

2. DIP
Original
Blur
Sharp
Edges

3. Bits per pixel (bpp)
Black color = 0

4. Image size Image size depends on: 1. Number of image rows
2. Number of image columns
3. Number of bits per pixel (bpp)
Image size = rows * columns * bpp

5. Image size 1024 rows 1024 columns 8 bits per pixel (8 bpp)
Image size = bits
Image size = Bytes
Image size = 1024 kBytes
Image size = 1 MBytes

6. 24-bit color format (RGB)
24-bit color format = True Color
Colors are distributed to 3 color channels
Color codes 8
Red
(255,0,0)
Green
(0,255,0) 8
Blue
(0,0,255) 8
Gray
(128,128,128)
(40,40,40)
(207,207,207)

7. 24-bit color format (CMYK)
C – Cyan
M – Magenta
Y – Yellow
K – Black
CMYK is used in color printers
Color codes
Cyan
(0,255,255)
Magenta
(255,0,255)
Yellow
(255,255,0)

8. RGB to grayscale conversion
Average method
Take the average of the three colors (R, G, B)
Weighted method
Takes into account the structure of the human eye

9. Average method Grayscale = (R + G + B)/3
The problem is that we take the average of three colors.
Different colors have different wavelength and different contribution to
image formation.
In average method we took 33% of red, 33% of green, 33% of blue
(each color have the same contribution to the image).

10. Weighted method
New grayscale image = (0.3 * R) + (0.59 * G) + (0.11 * B)
Contribution of red 33%, green 59%, blue 11%.

11. Example R = 206; G = 134; B = 84 Average method new pixel:
Weighted method new pixel:
X2 = 0.3* * =150.1=150
Weighted method usually gives brighter result.

12. Resolution For example: monitor resolution: 800 x 600 pixels
smart phone resolution: 720 x 1280 pixels
If the image has M rows and N columns, the resolution is M x N.
Megapixels of the camera: 2500 x 3192 pixels
pixel resolution = 2500 x 3192 = bytes
bytes / =7.9=8Megapixels

13. Aspect ratio
Ratio between the width and heigth of an image (for example 8:9, 16:10)

14. Example Aspect ratio 6:2, pixel resolution 480000 pixels. Calculate:
1. dimensions of the image
2. Size of the image
Solution: c:r = 6:2 (aspect ratio)
c*r = (pixel resolution)
bpp = 8

15. Example c=6*r/2 c=480000/r (6r/2)=480000/r r=400, c=1200 Size=r *c*bpp
Image size in bits: 400*1200*8= bits
Image size in bytes: bytes=48kBytes