SIMD Image Filter

A high-performance image filtering tool using SIMD (SSE2/SSE3) instructions for accelerated pixel processing.

Features

• Greyscale - Convert RGB images to single-channel greyscale using luminance formula
• Invert - Invert image colors (negative effect)
• Gaussian Blur - Apply configurable Gaussian blur with separable convolution
• Laplacian Edge Detection - Detect edges using Laplacian kernel

Requirements

• C++23 compatible compiler (GCC 13+ or Clang 16+)
• Boost (program_options)
• SSE2/SSE3 capable CPU

Building

make

Usage

./simd-filter -I <input.png> [-O <output.png>] [-F <filter>] [--blur-strength <value>]

Options

Option	Description	Default
-h, --help	Show help message	-
-I, --input-file	Input PNG file (required)	-
-O, --output-file	Output PNG file	out-<input>
-F, --filter	Filter type: greyscale, invert, gaussian, laplace	greyscale
--blur-strength	Gaussian blur strength (sigma = value/10)	10

Examples

# Convert to greyscale
./simd-filter -I cat.png -F greyscale -O greyscale.png

# Invert colors
./simd-filter -I cat.png -F invert -O invert.png

# Apply Gaussian blur (strength 20)
./simd-filter -I cat.png -F gaussian --blur-strength 20 -O gaussian.png

# Edge detection
./simd-filter -I cat.png -F laplace -O laplace.png

Example Results

Original

Greyscale

Invert

Gaussian Blur (strength=20)

Laplacian Edge Detection

Filter Details

Greyscale

Uses the standard luminance formula:

Y = 0.299*R + 0.587*G + 0.114*B

Implemented with fixed-point arithmetic for SIMD optimization.

Invert

Simple color inversion: output = 255 - input for each channel. Processes 16 bytes at a time using SSE2 instructions.

Gaussian Blur

• Uses separable 2-pass convolution (horizontal + vertical)
• Dynamically sized kernel based on blur strength
• Kernel radius = ceil(3 * sigma), covering 99.7% of distribution

Laplacian Edge Detection

Applies the Laplacian kernel after greyscale conversion:

[ 0 -1  0]
[-1  4 -1]
[ 0 -1  0]

License

MIT License

Copyright 2026 Vivek Dhiman (https://github.com/88VwV88)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.