C Image Processor

A command-line image processing application written in C, developed for SER 334: Operating Systems & System Programming at Arizona State University. The project demonstrates low-level image manipulation, BMP file handling, and multithreaded filtering using pthreads.

Features

This project supports two execution modes:

• Single-Image Processing (CLI Filters)
  • Black & white conversion
  • Color shifting (RGB adjustments)
  • Image resizing
• Multithreaded Filters (Parallel Processing)
  • Using MasonFilters.c, the program applies parallel image filters using pthreads, including:
    • Box Blur Filter
    • Swiss Cheese Filter (stylized effect with randomly generated circular holes)

Both modes operate on 24-bit uncompressed BMP images.

Project Structure

File structure:

• c-image-processor/
  • BMPHandler.c / BMPHandler.h (BMP file loading & saving)
  • Image.c / Image.h (Core image operations & filters)
  • MasonImageProcessor.c (CLI image processing (single-threaded))
  • MasonFilters.c (Multithreaded filters (pthreads))
  • ReadMe.txt (Original assignment notes)
  • wb.bmp (Sample input image)
  • ttt.bmp (Sample input image)

Requirements

• Linux environment (tested on Ubuntu / Xubuntu)
• gcc
• pthread library
• math library

Note: This project was developed and tested in a Linux VM and WSL (Ubuntu).

Build Instructions

From the project directory:

Compile the single-threaded image processor

gcc MasonImageProcessor.c BMPHandler.c Image.c -o ImageProcessor -lm

Compile the multithreaded filter processor

gcc MasonFilters.c BMPHandler.c Image.c -o MasonFilters -lm -pthread

Usage:

Single-Image Processing (CLI):

• Apply filters directly to an image:

./ImageProcessor input.bmp -r 56
./ImageProcessor input.bmp -w -r 56 -b 78 -g 45 -o output.bmp
./ImageProcessor input.bmp -s 2.0 -o resized.bmp

• Example options:
  • -w is Black & white
  • -r, -g, -b is RGB color shift
  • -s is Scale factor
  • -o is Output file

Multithreaded Filters:

• Apply parallel filters using pthreads:

./MasonFilters -i input.bmp -o blurred.bmp -f b
./MasonFilters -i input.bmp -o swiss.bmp -f c

• Filter options:
  • -f b is Box Blur filter
  • -f c is Swiss Cheese filter

Technical Highlights

• Manual parsing and writing of binary BMP files
• Safe memory allocation for image regions
• Column-based data decomposition for parallel execution
• Thread-safe design using pthreads
• Designed to scale across configurable thread counts

Why This Project Matters:

This project showcases:

• Strong C fundamentals
• Comfort with Linux envrionments
• Multithreaded programming concepts
• Real-world file I/O and memory management