How Computers Create Screen Images

1. The Pixel Foundation

Every image on your screen is composed of tiny dots called pixels (picture elements). A typical 1920×1080 screen contains over 2 million pixels!

Each pixel can display a specific color by mixing Red, Green, and Blue light in different intensities (RGB color model).

R: 255 G: 255 B: 255

2. From Digital to Physical

The computer's graphics system converts digital image data into electrical signals that control the physical display:

graph TD A[Application] -->|Image Data| B(Graphics Card) B -->|Digital Signal| C[GPU Processing] C -->|Video Signal| D[Display Connector] D -->|Electrical Signal| E[Monitor Electronics] E -->|Pixel Activation| F[Screen Image]

Simulation of CRT electron beam scanning (modern LCDs use different technology)

3. Frame Buffers & Refresh Rates

Computers store the screen image in a special memory area called a frame buffer:

Frame Buffer Structure

Memory Address | Pixel Data
0x0000 | [R,G,B]
0x0003 | [R,G,B]
... | ...
0xFFFF | [R,G,B]

Refresh Process

The GPU (Graphics Processing Unit) calculates what each pixel should display and updates the frame buffer. The display reads this buffer 60+ times per second (refresh rate) to create smooth motion.

Frame Time: 16.67ms
30Hz 60Hz 120Hz 240Hz