quadtree-image-compression

C implementation of a QuadTree-like BST for image segmentation and compression.

Quad Image BST

A C implementation of a Binary Search Tree (BST) data structure used to manage rectangular regions (quads) of an image.
This project demonstrates how image segmentation can be performed using recursive quadtree-like splitting, based on pixel similarity thresholds.

📌 Features

• Quad Structure: Represents rectangular image regions with metadata (tx, ty, w, h, sx, wsplit, key).
• BST Operations:
  • Insert, Search, Delete nodes
  • Inorder, Preorder, Postorder traversals
  • Recursive memory cleanup
• Image Processing Functions:
  • get_colour: Compute average pixel colour of a quad
  • similar: Determine if a quad’s pixels are within a similarity threshold
  • split_tree: Recursively split quads into smaller regions
  • drawOutline: Draw outlines of quads on the image
  • save_Quad: Replace quad pixels with averaged colour for compression

🖼️ Example Workflow

1. Load a grayscale image into memory
2. Initialize the root Quad (whole image as one region)
3. Build a BST of quads
4. Recursively split quads using similarity threshold
5. Save results:
   • Outlined Image → highlights quad borders
   • Compressed Image → quads filled with average colour

📂 File Structure

• Quad.c → Main implementation of BST + image functions
• imgUtils.c → Utility functions for image loading/saving (provided with assignment)

🔧 Compilation

To compile:

gcc Quad.c -o quad