UPGRADING REPAIRING PCs

Table 7.11 Scanner Troubleshooting Continued
Parallel Port Drives 203
Interface Type Problem Causes Solution
Acquire TWAIN or ISIS Verify scanner detected by
command in drivers not system; if scanner works
Photoshop or properly installed with its own software (not
other or registered in launched from another
programs system Registry; application), reinstall
won’t launch scanner turned drivers and verify Acquire
scanner off command works.
Graphics look Wrong Use Table 7.12
distorted scanning mode to determine best scanning
during scan set for
document
mode by document type.
Use Table 7.12 as a quick reference to help determine the best scanning
mode for your documents.
Table 7.12 Recommended Scanning Modes for Document Types
Color B&W Photo
Document Type Photo Drawing Text Scanning Mode
Line Art No Yes Yes No
OCR No No Yes No
Grayscale No Yes 1 No Yes
Color photo Yes No No Yes 2
Color halftone Yes 3 No No No
Color drawing No Yes No No
256-color No Yes No No
Copy/fax Yes 4 Yes 4 Yes 4 Yes 4
1. Recommended only for drawings containing pencil shading and ink wash effects
2. Use to convert color to black and white if photo-editing software conversion is unavailable or
produces inferior results
3. Adjust halftone options to match output device’s requirements
4. Use to prepare scanned image for sending as fax or when image will be photocopied; converts
all tones to digital halftones
Parallel Port Drives
Parallel ports were originally designed for printing, but have been
pressed into service for many different tasks, including tape, optical,
and removable-media drives.
Use Table 7.13 to help you get the most from parallel port interface
drives.