OpenCV Drawing Application

A simple interactive drawing application built with Python and OpenCV that allows users to create drawings and shapes with different colors and thicknesses.

Features

• Multiple drawing modes:
  • Freehand drawing
  • Circle drawing
  • Rectangle drawing
  • Line drawing
• Color options (Red, Green, Blue)
• Adjustable line thickness
• Save functionality

Requirements

• Python 3.x
• OpenCV (cv2)
• NumPy

To install the required packages:

pip install opencv-python numpy

Usage

1. Run the script:

python canvas.py

2. The application will open with a white canvas window.

Controls

• Mouse Controls:

  • Left Click + Hold: Draw/Create shapes
  • Release Left Click: Complete shape drawing

• Keyboard Controls:

  • m: Switch between drawing modes (freehand/circle/rectangle/line)
  • c: Change colors (Red/Green/Blue)
  • +: Increase line thickness
  • -: Decrease line thickness
  • s: Save drawing as "MyImage.png"
  • q: Quit application

Drawing Modes

1. Freehand Mode

   • Click and drag to draw freely

2. Circle Mode

   • Click for center point
   • Drag to set radius
   • Release to complete

3. Rectangle Mode

   • Click for first corner
   • Drag to opposite corner
   • Release to complete

4. Line Mode

   • Click for start point
   • Drag to end point
   • Release to complete

File Output

When saving, the drawing will be stored as "MyImage.png" in the same directory as the script.

Technical Details

• Canvas Size: 800x600 pixels
• Default Color: Red (BGR format: 0,0,255)
• Default Thickness: 2
• Image Format: PNG (when saving)

Error Handling

• The thickness cannot be reduced below 1
• The application can be safely closed using 'q' key or the window close button

Future Enhancements

Potential features for future versions:

• Additional shape options
• More color choices
• Undo/Redo functionality
• Layer support
• Custom canvas sizes