Image Processing Flashcards
7 cards from real CDIA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Image Processing flashcards as text
When scanning documents at 200 DPI versus 300 DPI, what is the primary trade-off?
Answer: 200 DPI has smaller files but may reduce OCR accuracy for small fonts
Lower DPI (200) produces smaller file sizes but may reduce OCR accuracy, especially for small or complex fonts that need more pixel detail.
What is 'line removal' preprocessing used for in document imaging workflows?
Answer: Eliminating horizontal and vertical lines (e.g., table borders, form lines) before OCR to improve character recognition
Line removal extracts horizontal and vertical ruling lines from forms or tables before OCR, preventing lines from being misread as characters.
Which image quality attribute is most directly affected by the bit depth of a scanner?
Answer: Tonal range and color accuracy
Bit depth determines how many distinct tonal values or colors can be captured, directly affecting the tonal range and color accuracy of the scanned image.
In document imaging, what does 'punch hole removal' accomplish?
Answer: Deletes binder holes from scanned pages by filling them with background color
Punch hole removal detects circular holes along document edges (from 3-hole punches) and fills them with the background color to prevent OCR errors.
What is the purpose of gamma correction in scanned document images?
Answer: Adjusting the nonlinear relationship between pixel values and actual brightness for accurate display
Gamma correction compensates for the nonlinear response of displays and scanners, ensuring that perceived brightness matches the intended tonal values.
Which technique is used to detect and correct for the curvature of text lines in book scanning?
Answer: Dewarping
Dewarping corrects the 3D distortion and curved text lines that result from book page curvature near the binding during flatbed scanning.
What does the term 'lossless compression ratio' mean in the context of document image compression?
Answer: The ratio of the original file size to the compressed file size with no image data lost
Lossless compression ratio is the factor by which file size is reduced without discarding any image data, so decompression perfectly reconstructs the original.