CDIA Scanning Technology 2 — Questions and Answers
Question 1: Which scanner type uses a stationary light source and moves the document past it using a roller mechanism?
- Flatbed scanner
- Sheet-fed scanner (Correct answer)
- Drum scanner
- Overhead scanner
Correct answer: Sheet-fed scanner
Sheet-fed scanners transport documents past a fixed scan head using rollers, making them ideal for high-volume document processing.
Question 2: What is the primary advantage of using a CIS (Contact Image Sensor) over a CCD in a document scanner?
- Higher optical resolution
- Greater color depth
- Thinner and lower power consumption (Correct answer)
- Better dynamic range
Correct answer: Thinner and lower power consumption
CIS sensors are much thinner and consume less power than CCD arrays because they don't require an optical reduction system.
Question 3: In document scanning, what does the term 'deskew' refer to?
- Removing background noise from scanned images
- Correcting the angular misalignment of scanned documents (Correct answer)
- Adjusting color balance in scanned images
- Removing blank pages from a scan batch
Correct answer: Correcting the angular misalignment of scanned documents
Deskewing is the automatic or manual correction of document rotation caused by slight misfeeds or placement errors during scanning.
Question 4: Which image file format uses lossless compression and supports transparency, making it suitable for certain scanned documents?
- JPEG
- PNG (Correct answer)
- BMP
- TIFF with JPEG compression
Correct answer: PNG
PNG uses lossless compression and supports transparency, preserving all image data without degradation.
Question 5: What is 'despeckle' as applied to scanned document images?
- A process to enhance color saturation
- Removal of random noise pixels from the scanned image (Correct answer)
- A technique to increase image sharpness
- A method to remove headers and footers
Correct answer: Removal of random noise pixels from the scanned image
Despeckle filters identify and remove isolated noise pixels (speckles) that typically result from document imperfections or scanner noise.
Question 6: A CDIA candidate is evaluating scanners for a project involving bound books. Which scanner type is most appropriate?
- Sheet-fed scanner
- Drum scanner
- Overhead book scanner (Correct answer)
- Microfilm scanner
Correct answer: Overhead book scanner
Overhead book scanners (also called planetary scanners) capture images without requiring the document to be fed through rollers, preserving bound books.
Question 7: What scanning parameter determines the number of bits used to represent each pixel in a grayscale image?
- Spatial resolution
- Bit depth (Correct answer)
- Scan speed
- Optical density
Correct answer: Bit depth
Bit depth (also called color depth or pixel depth) defines how many shades of gray can be represented per pixel; 8-bit grayscale yields 256 shades.
CDIA Scanning Technology 2
Which scanner type uses a stationary light source and moves the document past it using a roller mechanism?