# Resolution

## Gray Level Resolution

Gray-level resolution refers to the number of shades of gray which are used in preparing the image for display.

In the gray level resolution, the number of gray levels is an integer power of two and the most common value is 8 bits. It can vary depending on the application.

Digital images are having a higher gray-level resolution which is composed of a large number of gray shades. In Higher gray-level resolution, images are displayed at a greater bit depth than those of lower gray level resolution.

## BPP

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 numbers of a different color:

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)

## Gray level resolution and quantization

In the previous tutorial, we have studied digitizing of the analog signal is a two-step process:

1. Sampling
2. Quantization

Sampling is done in X-axis whereas quantization is done in Y-axis.

It means that digitizing the gray level resolution of an image is done in quantization.