Images and Graphics

1. Digital Image Representation

Digital image representation refers to the process of converting an image into a format that a computer can understand and process. In this process, an image is divided into small units called pixels (picture elements).

Each pixel stores information about:

• Color
• Brightness (intensity)

Images are represented in two main ways:

a. Raster Images (Bitmap)

Raster images are made up of a grid of pixels. Each pixel contains color information.
Example: Photographs.

• Quality depends on resolution (number of pixels)
• Enlarging the image may reduce quality (pixelation)

b. Vector Graphics

Vector graphics are created using mathematical equations and geometric shapes such as lines, curves, and polygons.

• Resolution-independent (no loss of quality when scaled)
• Used for logos, diagrams, and illustrations

2. Image and Graphics Format

Image formats define how image data is stored, compressed, and displayed. Different formats are used depending on the purpose.

Common Image Formats:

• JPEG (JPG):
  • Uses lossy compression
  • Suitable for photographs
• PNG:
  • Uses lossless compression
  • Supports transparency
• GIF:
  • Supports animation
  • Limited color range (256 colors)
• BMP:
  • Uncompressed format
  • Large file size
• SVG:
  • Vector format
  • Scalable without quality loss

Graphics formats may include both raster and vector formats depending on the application.

3. Image Synthesis

Image synthesis is the process of generating images artificially using computers rather than capturing them from real-world objects.

It is widely used in:

• Computer graphics
• Animation and movies
• Video games
• Virtual reality

Techniques used in image synthesis include:

• Rendering
• Modeling
• Shading

4. Image Analysis

Image analysis refers to the process of extracting meaningful information from images using computational techniques.

It involves:

• Identifying objects
• Detecting patterns
• Measuring features

Applications include:

• Medical imaging (X-rays, MRI)
• Face recognition systems
• Surveillance systems

5. Image Transmission

Image transmission is the process of sending digital images from one system to another through communication networks.

Steps involved:

1. Image capture (camera/scanner)
2. Conversion to digital format
3. Compression to reduce file size
4. Transmission over network
5. Decompression and display

Challenges in image transmission:

• Large file size
• Bandwidth limitations
• Data loss or distortion

Conclusion

Images and graphics are essential components of multimedia systems. They allow visual representation of information and play a key role in communication, entertainment, and data analysis. Efficient representation, processing, and transmission of images are crucial for modern multimedia applications.