2D & 3D Scanners
Computer Science: Cambridge International GCSE, topic 1.3.8
Two-Dimensional Scanners
Two-dimensional scanners convert physical documents into digital files. Scanners come in flatbed and handheld form. Many printers have built-in flatbed scanners.
How does it work?
- A bright strip light illuminates and scans across the document.
- The scanner creates a digital image based on the amount of light reflected from the document.
- Optical character recognition (OCR) software installed on a computer can convert scanned images into editable text.
Applications
- 2D scanners are used to convert a physical version of a document into a digital form for storage, distribution, or editing.
- For example, airport staff will scan your passport in order to check its validity before you can fly.
- Specialist scanners can convert old format material such as film negatives into digital files.
Advantages of 2D scanners
- Flatbed scanners produce high-quality images.
- Images once digitised can be enhanced with a graphics application like Photoshop.
- Digital copies of documents can be sent electronically, stored securely, or edited.
Disadvantages of 2D scanners
- Scanned documents can take a lot of computer memory to store.
- Images lose some quality in the scanning and digitising process.
- Flatbed scanners take up a large amount of space on a desk compared to handheld scanners.
Three-Dimensional Scanners
A three-dimensional scanner creates a digital 3D model of an object using electromagnetic waves. 3D scanners work by scanning from different positions around the object.
How does it work?
- An object is scanned along three axes using lasers, light, radio waves or X-rays.
- Some 3D scanners scan through thin slices of the object by using waves with certain frequencies to look inside objects.
- These scanners typically use gamma, radio and X-rays.
- The scanned images are then edited in computer-aided design (CAD) software.
- This allows the object itself to be duplicated using a 3D printer.
Applications
- 3D scanners have many uses, including:
- Airport security screenings to check for restricted items.
- Capturing the physical measurements of an object.
- Obtaining biometric data for medical treatments or identification.
- Creating digital characters based on real human attributes.
Advantages of 3D scanners
- 3D scanners are a noninvasive way of searching through clothing.
- 3D scanning provides accurate measurements to create computer models.
- 3D scanners can easily measure and catalogue unusually shaped objects.
Disadvantages of 3D scanners
- Some 3D scanners are typically large, sometimes as big as a wardrobe!
- Repeated exposure to X-rays in medical scanners can be harmful to the operator of the scanner.
- 3D scanners are expensive.