Concept of Bits Per Pixel
BPP or Bits per Pixel is used to denote the number of bits per pixel and the number depends on the depth of color or BPP.
Bits
A bit also known as a binary digit is the smallest unit of data in a computer. A bit has 0 or 1.
Formula:
Following are the number of different colors:
| Bits per pixel | Number of colors |
|---|---|
| 1 bpp | 2 colors |
| 2 bpp | 4 colors |
| 3 bpp | 8 colors |
| 4 bpp | 16 colors |
| 5 bpp | 32 colors |
| 6 bpp | 64 colors |
| 7 bpp | 128 colors |
| 8 bpp | 256 colors |
| 10 bpp | 1024 colors |
| 16 bpp | 65536 colors |
| 24 bpp | 16777216 colors (16.7 million colors) |
| 32 bpp | 4294967296 colors (4294 million colors) |
Shades
The human eye can distinguish hundreds of color shades and their intensities. There are 100 shades of grey; therefore, an image contains extra information of color and this information is used for image analysis.
For example: Identification of object and extraction based on color.
Image storage requirements
Image size
The size of an image depends on three things they are as following :
- Number of rows
- Number of columns
- Number of bits per pixel
The formula for calculating the size of the image:
Example:
Let row be 3000 and columns be 1687, and it has 256 shades of bpp.
Size of an image = rows * cols * bpp
=3000 * 1687 * 8
=40488000 bits
As it is not a standard answer so we can convert it in the following ways:
Converting it into bytes = 8388608 / 8 = 5061000 bytes.
Converting into kilo bytes = 5061000 / 1024 = 4942kb.
Converting into Mega bytes = 4942 / 1024 = 4 Mb.