Project 6: Gesture-Controlled Presentation System

Control PowerPoint/PDF presentations using hand gestures - perfect for touchless presenting.

What You’ll Learn

  1. Hand Detection - Using MediaPipe
  2. Landmark Extraction - 21 hand keypoints
  3. Gesture Recognition - Finger states and movements
  4. Screen Automation - pyautogui integration
  5. Gesture Debouncing - Smooth interaction

Supported Gestures

Gesture Action
Swipe Left Next slide
Swipe Right Previous slide
Open Palm Pause/Black screen
Fist Resume
Thumbs Up Volume up
Peace Sign Volume down

Usage 

# Demo mode (visualization only)
python main.py --demo

# Full control mode
python main.py --control

Hand Landmarks

MediaPipe detects 21 landmarks per hand:

        8   12  16  20
        |   |   |   |
    4   7   11  15  19
    |   |   |   |   |
    3   6   10  14  18
    |   |   |   |   |
    2   5   9   13  17
    |    \  |  /   /
    1      \|/   /
    |       0---/
    WRIST

Gesture Detection Logic

Finger State Detection 

# Finger is extended if tip is above pip joint
is_extended = landmarks[tip]['y'] < landmarks[pip]['y']

Swipe Detection 

# Track position history
# Detect significant horizontal movement
if abs(dx) > threshold:
    return 'swipe_right' if dx > 0 else 'swipe_left'

Key Dependencies

Library Purpose
MediaPipe Hand detection and landmarks
pyautogui Keyboard/mouse automation
OpenCV Image processing and display

Code Highlights

Finger States 

# Finger tip and pip (second joint) indices
tips = [4, 8, 12, 16, 20]
pips = [3, 6, 10, 14, 18]

# Check if tip is above pip (finger extended)
for tip, pip in zip(tips[1:], pips[1:]):
    fingers.append(lm[tip]['y'] < lm[pip]['y'])

Gesture Cooldown 

# Prevent repeated triggers
if current_time - last_action_time < cooldown:
    return None  # Skip this gesture

Real-World Applications

  • Touchless presentations
  • Accessibility interfaces
  • Smart home control
  • Gaming input
  • Sign language recognition

Performance Tips

  1. Use max_hands=1 for better performance
  2. Implement gesture cooldown
  3. Use position history for swipe detection
  4. Flip camera for mirror effect

References