Day 4 - Binary Representation of Images and Sound

Day 4: Binary Representation of Images and Sound

DAT-1.C: For binary sequences in a computer, identify the data type, and interpret the values.

Review and Connection (3 minutes)
- Review text encoding from previous lesson
- Connect to today's focus on image and sound representation
Warm-up Activity (5 minutes)
- Display a simple image and ask: "How might this be stored as 0s and 1s?"
- Play a short audio clip and ask the same question

Lecture: Image Representation (12 minutes)
- Explain how images are represented as grids of pixels
- Introduce resolution and its impact on image quality
- Explain color depth:
  - 1-bit (black and white)
  - 8-bit (256 colors)
  - 24-bit (16.7 million colors)
- Demonstrate the RGB color model and how colors are encoded
- Show how increasing bits per pixel affects image quality and file size
- Briefly mention other color models (CMYK, HSL)
Demo: Pixel Representation and Color Depth (5 minutes)
- Show the same image at different resolutions
- Demonstrate zooming in to see individual pixels
- Show the same image at different color depths
- Demonstrate how RGB values combine to create different colors
Activity: Creating Pixel Art (10 minutes)
- Students create simple pixel art on grid paper
- For each pixel, students specify the color using RGB values
- Students translate a small section of their art into binary representation
- Optional: Use digital tools to create pixel art if computers are available
Lecture: Sound Representation (5 minutes)
- Explain how sound waves are digitized through sampling
- Introduce sampling rate (samples per second) and its effect on quality
- Explain audio bit depth and its impact on dynamic range
- Demonstrate how higher sampling rates and bit depths affect audio quality and file size

Discussion: Quality vs. File Size (5 minutes)
- Play audio samples with different sampling rates/bit depths
- Show images with different resolutions/color depths
- Discuss the trade-offs between quality and file size
- Ask students to consider: When is higher quality necessary? When is it wasteful?
Assessment and Preview (5 minutes)
- Students create a simple image and explain its digital representation
- Preview that next class will focus on data abstraction and file formats

Complete a worksheet calculating image file sizes based on resolution and color depth
Create a more complex piece of pixel art with corresponding RGB values
Research how a specific digital media format (JPEG, MP3, etc.) represents data

Have examples ready that clearly show the effects of resolution and color depth
Make connections to students' experiences with digital photos and music
Emphasize that understanding these representations helps with making informed choices about digital media
Consider bringing in examples of older technology to show how representation has evolved