7.A] Define Image Processing. With a neat diagram, explain the image processing environment.
Amswer:
Image processing is the process of transforming an image into a digital form and performing certain operations to get some useful information from it.
Nature of Image Processing / Image Processing Environment:
There are three scenarios or ways of acquiring an image
- Reflective mode Imaging
- Emissive Type Imaging
- Transmissive Imaging
The radiation source shown in Figure is the light source.
Objects are perceived by the eye because of light. The sun, lamps, and clouds are all examples of radiation or light sources. The object is the target for which the image needs to be created. The object can be people, industrial components, or the anatomical structure of a patient. The objects can be two-dimensional, three-dimensional or multidimensional mathematical functions involving many variables. For example, a printed document is a 2D object. Most real-world objects are 3D.
1. Reflective Mode Imaging
- Reflective mode imaging is the most basic form of capturing images. It involves using a sensor to acquire digital images.
- Common devices like video cameras, digital cameras, and scanners use sensors to capture images by converting light energy into electrical signals.
2. Emissive Type Imaging
- Emissive imaging captures images from objects that emit their own light, without needing an external light source.
- Examples include:
- Thermal Imaging: Uses thermal cameras to create images based on the temperature of objects, useful in low-light conditions.
- Magnetic Resonance Imaging (MRI): Captures images based on magnetic properties of the body’s tissues.
- Positron Emission Tomography (PET): Creates images by detecting radiation emitted by a tracer injected into the body.
3. Transmissive Imaging
- In transmissive imaging, an external radiation source (like X-rays) passes through an object.
- The object absorbs some of the radiation, while the rest passes through and is captured to form an image.
- Examples include:
- X-ray Imaging: Used in medical diagnostics to view inside the body.
- Microscopic Imaging: Used to view small objects or details that are not visible to the naked eye.
- Ultrasound Imaging: Uses sound waves to create images, often used in medical imaging.