Imaging Principles and Processing Techniques

Study Notes

Principles of Imaging

Imaging relies on the interaction of electromagnetic radiation or other probes with the object being imaged.
The interaction results in a signal that carries information about the object's structure, composition, or other properties.
Different imaging modalities utilize different types of radiation or probes.
Signal acquisition involves capturing the emitted or scattered radiation.

Image Processing Techniques

Image processing techniques enhance, restore, or analyze image data.
Common techniques include:
- Image enhancement: Improves image quality by adjusting brightness, contrast, or sharpness.
- Image restoration: Aims to remove blurring, noise, or other degradations.
- Image segmentation: Divides the image into different regions based on intensity or other characteristics.
- Feature extraction: Identifies important features from the image.
- Image compression: Reduces the size of the image file while maintaining quality.
These techniques often involve mathematical operations on the image data.

Digital Imaging

Digital imaging represents images as numerical data.
This data is stored and manipulated using computers.
Pixelation/pixel: The smallest element of the image.
Resolution: Accuracy of measurement/number of pixels.
Image format: Determines the way image data is encoded and stored.
Examples of formats include JPEG, PNG, TIFF.
Image acquisition: The process of obtaining the image data.
Image display: The process of presenting the digital image to a user, on a monitor or a physical medium.
Image analysis: the process of extracting data from the image, for example, object detection, sizing or classification.

Optical Imaging

Optical imaging utilizes light to create images.
It encompasses a wide range of techniques:
- Microscopy (light microscopy, fluorescence microscopy): Visualizing small structures at high resolution, using light illumination and specific dye markers to illuminate/highlight those structures.
- Optical coherence tomography (OCT): A non-invasive technique that uses light to create cross-sectional images of tissues and internal structures.
- Optical coherence tomography angiography (OCTA): A non-invasive imaging technique used to visualize and analyze blood flow patterns in the body's tissues and organs.
- Hyperspectral Imaging: acquiring images that encode a wide range of wavelengths of visible/near-infrared light (can be used in agriculture, pathology and other sciences)
The interaction of light with the object being imaged determines the information captured.
Optical imaging techniques have applications in medicine, biology, and materials science.
Different techniques are optimized for specific applications, ranging from imaging of cells and tissues to industrial inspection and medical diagnosis.
Principles of lens design and light propagation are crucial for understanding and improving optical imaging systems.

Description

This quiz explores the principles of imaging, focusing on the interaction of electromagnetic radiation with objects and the resulting signal acquisition. It also covers various image processing techniques such as enhancement, restoration, segmentation, and feature extraction, all crucial for analyzing and improving image data.