Demonstration of image compression using SVD. The original image (left) is approximated using a rank 10 SVD (middle) and a rank 25 SVD (right).
How Engineers Use Linear Algebra for Image Compression and Signal Processing
Linear algebra is a core subject in engineering—not just because it’s required, but because it directly supports some of the most powerful technologies used today. One area where this becomes clear is in image compression and signal processing.
From the photos we take to the music we stream, and the medical scans used in hospitals, engineers use linear algebra tools like Singular Value Decomposition (SVD) to compress, clean, and analyze data. In this article, we’ll explore how SVD and other matrix techniques work behind the scenes to solve real-world engineering problems.
Why Image and Signal Compression Matters in Engineering
Modern systems generate large volumes of data:
High-resolution images and video
Real-time audio and sensor feeds
Medical imaging files (MRI, CT)
Engineering simulation results
This data must often be stored, transmitted, or processed quickly and efficiently. But working with raw, full-resolution files is computationally expensive. Engineers solve this by using compression—and that’s where linear algebra plays a critical role.
Modeling Images and Signals as Matrices
Before compression or filtering can happen, data must be structured.
A grayscale image is stored as a 2D matrix of pixel values (intensity from 0 to 255).
A color image consists of three matrices: red, green, and blue channels.
Audio signals are represented as arrays or segmented into 2D matrices for time-frequency analysis.
Once in matrix form, data becomes ready for linear algebra-based manipulation.
Singular Value Decomposition (SVD): The Key to Compression
The Singular Value Decomposition is one of the most powerful matrix tools used by engineers. It breaks any matrix A into three matrices:
A=UΣVT
Where:
U and V are orthogonal matrices
Σ is a diagonal matrix containing singular values
These singular values tell us how much of the image or signal’s structure is captured in each component. By retaining only the top k singular values, engineers can rebuild a close approximation of the original data—drastically reducing size and complexity.
This is a mathematical foundation for many compression techniques, including those with similar underlying principles to JPEG. While JPEG itself primarily uses the Discrete Cosine Transform (DCT) for compression, the concept of representing data in a basis where most of the important information is concentrated in a few components, as seen in SVD, is a shared principle.
See It in Action
To see how SVD works with real numbers and matrices, watch this video from my linear algebra series: Singular Value Decomposition (SVD) | Step-by-Step Example and Explanation
Engineering Applications of SVD and Linear Algebra
Image Processing
Compression: JPEG and other formats use techniques with similar mathematical foundations to SVD to reduce file size without noticeable loss in quality.
Facial Recognition: Uses SVD and PCA (which is mathematically related to SVD, often performed on the covariance matrix of the data) to extract essential features.
Medical Imaging: Enhances quality and reduces storage of MRI, CT, and ultrasound data.
Signal Processing
Noise Reduction: Filters out unwanted noise from biomedical, radar, sonar, and communication signals.
Spectral Analysis: Uses matrix operations to separate signal components by frequency.
Telecommunications: Compression allows faster data transmission with lower bandwidth.
Machine Learning and AI
Dimensionality Reduction: PCA, a powerful technique built upon the principles of SVD (often by applying SVD to the covariance matrix), reduces the number of features in large datasets while retaining the most important information.
Latent Semantic Analysis (LSA): In natural language processing, SVD reveals hidden relationships between words and documents.
More Matrix Tools Engineers Use
SVD is just one part of a larger toolkit. Engineers frequently use:
Eigenvalue decomposition – for analyzing vibrations and stability
Fourier transforms – often implemented with matrix multiplications
Toeplitz and circulant matrices – in digital filtering and convolution
QR and LU decompositions – to solve linear systems in real-time
These are built on the same fundamental ideas: vector spaces, matrix transformations, and efficient computation.
Learn the Linear Algebra That Engineers Use Every Day
If you're studying engineering, learning linear algebra isn't just about passing exams—it’s about developing skills that translate directly into your career. From signal processing to AI to robotics, these tools are used to solve real-world problems every day.
To learn more, explore my free Linear Algebra YouTube Playlist, which includes:
Clear step-by-step examples
Conceptual explanations
Practical applications in engineering
Watch the full Linear Algebra Playlist here
Conclusion
Linear algebra isn’t just a classroom subject—it’s a language engineers use to solve complex, data-intensive problems. Whether you're compressing a photo or analyzing a biomedical signal, tools like the Singular Value Decomposition give you efficient, elegant solutions.
If you're learning this material, keep going. You're gaining a toolkit that engineers rely on every day.