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IMAGE ACQUISITION PROCESS
What is Image Acquisition?
In the simplest terms, image acquisition is the process of capturing visual
information from the real world and converting it into a digital image that
computers can process. Think of it as snapping a photo with your smartphone—
the moment you hit the shutter button, you’re acquiring an image. Whether it’s a
medical scan, a satellite photo, or a selfie, the fundamental goal remains the
same: to translate physical scenes into digital data that can be analyzed, edited, or
enhanced.
However, image acquisition isn’t just about taking pictures. It involves a variety of
devices and technologies, from digital cameras and scanners to more complex
systems like X-ray machines and LiDAR sensors. Each tool uses different methods
to capture and convert light into pixelated data.
For instance, a digital camera uses a sensor to detect light and store it as digital
information. At the same time, a scanner might utilize a different approach to
capture highly detailed images of documents.
Common image Acquisition Devices
1. Digital Cameras(e.g. Smartphones, webcam)
2. Scanners
3. Medical Imaging Devices(X-ray, MRI, Ultrasound)
4. Microscopes
5. Satellite
6. Drones
Image Acquisition in Image Processing
The image must first be captured before any processing can occur—such as
enhancing image clarity, detecting objects, or applying filters. The quality of this
raw data significantly impacts the effectiveness of subsequent processing
algorithms.
In image processing, the quality and type of acquired image can significantly
impact the end results. Let’s say you’re developing a facial recognition system. The
lighting conditions, resolution, and angle at which the image was captured can all
influence the accuracy of your results. You might use high-resolution cameras for
detailed pictures or infrared sensors for night vision applications.
Processes involved in Image Acquisition
1. Capturing the Image
Light and Reflection:
The process begins with light reflecting off the object of
interest.
The Source of light may be natural (e.g. sun) or artificial (e.g.
ring light).
Focusing: The light is then focused onto the sensor (e.g. CCD or CMOS
sensor in a digital cameras).
Sensor: The sensor converts the light energy into electrical signals,
capturing the image.
2. Digitization
Analog-to-Digital Conversion: The electrical signals are then
converted into a digital format (binary values).
Image Formation:
The digital values are organized into a grid (rows and columns)
forming a digital image.
Each value (called a pixel) represents the intensity and color at
that point in the image.
3. Preprocessing
The image may go through enhancement processes like noise
reduction, contrast adjustment, or geometric corrections before
further use.
4. Image Storage and Processing
Storage: The digital image is stored as a file (e.g. JPEG, PNG)
Processing: The image can then be processed further using software,
algorithms or other techniques for various purposes like
enhancement, analysis or manipulation.
