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Quality Assurance - Image Defects

<strong>QA Image Defects</strong> This page provides references for Stanford University Libraries Digital Production Group staff members performing imaging and Image QC auditing. This page is freely shared with vendors and partner institutions.

Additional information is available on the University of Maryland Libraries webpage for "Common Imaging Problems" by Steven Puglia, Jeffrey A. Reed, Erin Rhodes, National Archives and Records Administration

Stanford University Libraries "Cropping Guide" is also available online and for download.

Audio and video reformatting defects are available at Stanford University Libraries "A/V Artifact Atlas".

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ExamplesDescriptionsAppearancesCausesRemedies
Crop: text cut-off (unacceptable, acceptable) Broad: Item runs out of frame or out of view
Narrow: Portion of text not visible
Broad: Imaging setup defect
Narrow: Image framed too close (or cropped in post-process)
Remake with a wider frame
Crop: text cut-off (unacceptable, acceptable) Broad: Item runs out of frame or out of view
Narrow: Portion of text not visible
Broad: Imaging setup defect
Narrow: Image framed too close (or cropped in post-process)
Remake with a wider frame
Crop: text cut-off (unacceptable) Broad: Item runs out of frame or out of view
Narrow: Portion of text not visible
Broad: Imaging setup defect
Narrow: Image framed too close (or cropped in post-process)
Remake with a wider frame
Digital artifacts: banding or posterization (unacceptable, acceptable) Broad: Abrupt changes in or exaggerated color or tonal gradation
Narrow: Banding, color or tonal posterization
Broad: Imaging system defect
Narrow: Raw file processing error or poorly made gain or LCC file
Diagnose and tune the processing system or re-create the gain file before remaking the image file
Digital artifacts: banding or posterization (unacceptable, acceptable) Broad: Abrupt changes in or exaggerated color or tonal gradation
Narrow: Banding, color or tonal posterization
Broad: Imaging system defect
Narrow: Raw file processing error or poorly made gain or LCC file
Diagnose and tune the processing system or re-create the gain file before remaking the image file. Verify that the source materials do not contain the discoloration.
ExamplesDescriptionsAppearancesCausesRemedies
Digital artifacts: banding (unacceptable) Broad: Pattern of lines extending across the frame, most apparent in darker values
Narrow: Banding, "horizontal stripes"
Broad: Imaging system defect
Narrow: Raw file processing error
Diagnose and fix or tune the imaging system
Digital artifacts: banding (unacceptable) Broad: Pattern of lines extending across the frame, most apparent in darker values
Narrow: Banding, "horizontal stripes"
Broad: Imaging system defect
Narrow: Raw file processing error
Diagnose and fix or tune the imaging system
Digital artifacts: banding (unacceptable) Broad: Pattern of lines extending across the frame, most apparent in darker values
Narrow: Banding, "horizontal stripes"
Broad: Imaging system defect
Narrow: Raw file processing error
Diagnose and fix or tune the imaging system
Digital artifacts: banding (unacceptable) Broad: Defect on a line or a small number of lines
Narrow: Banding, "vertical stripes"
Broad: Imaging system defect
Narrow: Raw file processing error
Diagnose and fix or tune the imaging system
Digital artifacts: blocking defect (unacceptable) Broad: Defect on a line or a number of lines in an array
Narrow: Jagged lines
Broad: Imaging system defect
Narrow: Raw file processing error
Diagnose and fix or tune the imaging system
ExamplesDescriptionsAppearancesCausesRemedies
Digital artifacts: blocking defect (unacceptable) Broad: Defect on a line or a number of lines in an array
Narrow: Jagged lines
Broad: Imaging system defect
Narrow: Raw file processing error
Diagnose and fix or tune the imaging system
Digital artifacts: blocking defect (unacceptable) Broad: Defect on a line or a number of lines in an array
Narrow: Jagged lines
Broad: Imaging system defect
Narrow: Raw file processing error
Diagnose and fix or tune the imaging system
Digital artifacts: cameraback defect (unacceptable) Broad: Defect on a line or a small number of lines
Narrow: Loss of alignment; pixel/row offset
Broad: Imaging system defect
Narrow: Raw file processing error or hardware defect such as dirt on scanner platen or dead sensors
Diagnose and fix or tune the imaging system
Digital artifacts: channel misregistration (unacceptable) Broad: Color fringing, especially visible in areas of high contrast
Narrow: Color fringing or color channel offset
Broad: Imaging system defect
Narrow: Sensor misalignment or processing error
Diagnose and fix or tune the imaging system
Digital artifacts: channel misregistration (unacceptable, acceptable) Broad: Color fringing, especially visible in areas of high contrast
Narrow: Color fringing or color channel offset
Broad: Imaging system defect
Narrow: Sensor misalignment or processing error
Diagnose and fix or tune the imaging system
ExamplesDescriptionsAppearancesCausesRemedies
Digital artifacts: channel misregistration (unacceptable) Broad: Color fringing, especially visible in areas of high contrast
Narrow: Color fringing or color channel offset
Broad: Imaging system defect
Narrow: Sensor misalignment or processing error
Diagnose and fix or tune the imaging system
Digital artifacts: color cast (unacceptable, acceptable) Broad: Poor color or tonal fidelity
Narrow: Colors or tones do not resemble source material
Broad: Imaging system defect or post-processing error
Narrow: Error caused by poor color management or processing settings
Remake after adjusting processing or color profile settings
Digital artifacts: compression artifacts (unacceptable)) Broad: Visual texture
Narrow: Patterned texture, most apparent in high-contrast areas, pixel-set squares not easily visible
Broad: Scan specification artifact
Narrow: Lossy compression applied or set too high
Remake with no or lossless compression
Digital artifacts: compression artifacts (unacceptable)) Broad: Visual texture
Narrow: Patterned texture, most apparent in high-contrast areas, pixel-set squares not easily visible
Broad: Scan specification artifact
Narrow: Lossy compression applied or set too high
Remake with no or lossless compression
Digital artifacts: compression artifacts (unacceptable) Broad: Visual texture
Narrow: Patterned texture, most apparent in high-contrast areas, pixel-set squares not easily visible
Broad: Scan specification artifact
Narrow: Lossy compression applied or set too high
Remake with no or lossless compression
ExamplesDescriptionsAppearancesCausesRemedies
Digital artifacts: compression artifacts (unacceptable) Broad: Visual texture
Narrow: "Ringing" at dark-light edges
Broad: Scan specification artifact
Narrow: Lossy compression applied or set too high
Remake with no or lossless compression
Digital artifacts: microfilm scanning compression artifacts (unacceptable) Broad: Visual texture
Narrow: "Ringing" at dark-light edges, also patterned texture visible
Broad: Scan specification artifact
Narrow: Lossy compression applied or set too high
Remake with no or lossless compression
Digital artifacts: noise (unacceptable) Broad: Visual texture
Narrow: In dark area, colored dots visible (hard to discern in light areas)
Broad: Imaging system defect
Narrow: Raw file processing error or poorly made gain or LCC file
Remake after adjusting processing settings or with a different device
Digital artifacts: poor color rendering (unacceptable) Broad: Poor color or tonal fidelity
Narrow: Colors or tones do not resemble source material
Broad: Imaging system defect or post-processing error
Narrow: Error caused by poor color management or processing settings
Remake after adjusting processing or color profile settings
Digital artifacts: scanning chatter/misalignment (unacceptable) Broad: Defect on a line or a small number of lines
Narrow: Distortion along a line (vertical as shown) with obvious color fringing
Broad: Scanning system defect
Narrow: Scanner mechanical defect or device was bumped during scan
Limit movement around active scanning and rescan; if mechanical, fix the device
ExamplesDescriptionsAppearancesCausesRemedies
Digital artifacts: scanning chatter/misalignment (unacceptable) Broad: Defect on a line or a small number of lines
Narrow: Distortion along a line (vertical as shown) with obvious color fringing
Broad: Scanning system defect
Narrow: Scanner mechanical defect or device was bumped during scan
Limit movement around active scanning and rescan; if mechanical, fix the device
Digital artifacts: scanning chatter/misalignment (unacceptable) Broad: Defect on a line or a small number of lines
Narrow: Distortion along a line (horizontal as shown), hard to see
Broad: Scanning system defect
Narrow: Scanner mechanical defect or device was bumped during scan
Limit movement around active scanning and rescan; if mechanical, fix the device
Digital artifacts: scanning chatter/misalignment (unacceptable, acceptable) Broad: Defect on a line or a small number of lines
Narrow: Distortion along a line (vertical as shown) with obvious color fringing
Broad: Scanning system defect
Narrow: Scanner mechanical defect or device was bumped during scan
Limit movement around active scanning and rescan; if mechanical, fix the device
Digital artifacts: scanning chatter/misalignment (unacceptable, acceptable) Broad: Defect on a line or a small number of lines
Narrow: Distortion along a line (vertical as shown) with obvious color fringing
Broad: Scanning system defect
Narrow: Scanner mechanical defect or device was bumped during scan
Limit movement around active scanning and rescan; if mechanical, fix the device
Digital artifacts: scanning chatter/misalignment (unacceptable) Broad: Defect on a line or a small number of lines
Narrow: Distortion along a line (horizontal as shown), hard to see
Broad: Scanning system defect
Narrow: Scanner mechanical defect or device was bumped during scan
Limit movement around active scanning and rescan; if mechanical, fix the device
ExamplesDescriptionsAppearancesCausesRemedies
Digital artifacts: loss of information/detail (unacceptable) Broad: Lack of fine detail, artificially smooth, blurred areas of color
Narrow: Detail and texture does not resemble source material
Broad: Post-processing error
Narrow: Error caused by excessive post-processing/use of noise reduction, blur or despeckle filters
Remake from RAW little or no noise reduction filtering
Digital artifacts: loss of information/detail (unacceptable) Broad: Lack of fine detail, artificially smooth, blurred areas of color
Narrow: Detail and texture does not resemble source material
Broad: Post-processing error
Narrow: Error caused by excessive post-processing/use of noise reduction, blur or despeckle filters, or excessive wavelet compression (JPEG 2000)
Remake from RAW little or no noise reduction filtering
Illumination: mixed lighting (unacceptable, acceptable) Broad: Tonal and color variation in film scan
Narrow: Washed-out and discolored area (right side)
Broad: Imaging system defect
Narrow: Uneven color and tonality caused by multiple light sources or pooly made gain file
Remake after normalizing the light source(s), minimizing light reflections from colored walls or objects, closing window shades, and/or turning-off overhead lights
Illumination: uneven processing (acceptable) Broad: Tonal variation in film scan
Narrow: Dark area (right side) and washed out foreground
Broad: Poor film processing of source material
Narrow: Uneven densities/tones and occasional staining caused by poorly processed film
Although retouching might improve the image, this is generally acceptable if it accurately represents the source material
Illumination: uneven lighting (unacceptable) Broad: Tonal variation in photo
Narrow: Light area (lower left) and dark area (center), echoed in the background material
Broad: Uneven lighting
Narrow: Lights not properly adjusted or positioned
Remake after adjusting the position, power, and modifications of the light sources
ExamplesDescriptionsAppearancesCausesRemedies
Illumination: uneven lighting (unacceptable) Broad: Tonal variation in photo
Narrow: Light area (lower left) and dark area (center), echoed in the background material
Broad: Uneven lighting
Narrow: Lights not properly adjusted or positioned
Remake after adjusting the position, power, and modifications of the light sources
Illumination: uneven lighting (unacceptable) Broad: Tonal variation in photo
Narrow: Light area (lower left) and dark area (center), echoed in the background material
Broad: Uneven lighting
Narrow: Lights not properly adjusted or positioned
Remake after adjusting the position, power, and modifications of the light sources
Moire: Bayer moire (unacceptable, acceptable) Broad: Visual texture
Narrow: Faint color pattern (original is lithographic-type print)
Broad: Scanning system defect
Narrow: Artificial pattern of colors appearing in the image; moire caused by the overlay of a patterned image on a pixel-array device's Bayer filter sensor
Remake at different PPI (oversample) or with different technology
Moire: Bayer moire (unacceptable, acceptable) Broad: Visual texture
Narrow: Faint color pattern (original is copperplate engraving)
Broad: Scanning system defect
Narrow: Artificial pattern of colors appearing in the image; moire caused by the overlay of a patterned image on a pixel-array device's Bayer filter sensor
Remake at different PPI (oversample) or with different technology
Moire: Bayer moire (unacceptable, acceptable) Broad: Visual texture
Narrow: Faint color pattern in foredge
Broad: Scanning system defect
Narrow: Artificial pattern of colors appearing in the image; moire caused by the overlay of a patterned image on a pixel-array device's Bayer filter sensor
Remake at different PPI (oversample) or with different technology
ExamplesDescriptionsAppearancesCausesRemedies
Moire: Bayer moire (unacceptable) Broad: Visual texture
Narrow: Color pattern (on black and white original), dots relatively visible (original is printed halftone)
Broad: Scanning system defect
Narrow: Artificial pattern of colors appearing in the image; moire caused by the overlay of a patterned image on a pixel-array device's Bayer filter sensor
Remake at different PPI (oversample) or with different technology
Moire: Bayer moire (unacceptable) Broad: Visual texture
Narrow: Color pattern (on black and white original), dots relatively visible (original is printed halftone)
Broad: Scanning system defect
Narrow: Artificial pattern of colors appearing in the image; moire caused by the overlay of a patterned image on a pixel-array device's Bayer filter sensor
Remake at different PPI (oversample) or with different technology
Moire: halftone pattern moire (unacceptable) Broad: Visual texture
Narrow: Black and white moire (on black and white original), relatively visible (original is printed halftone)
Broad: Scan specification artifact
Narrow: Artificial pattern appearing in the image; moire caused by the overlay of a patterned image on a pixel-array device's Bayer filter sensor
Remake at different PPI (oversample) or with different technology
Moire: Newton's Rings (unacceptable) Broad: Visual texture
Narrow: Usually a pattern of multi-colored, concentric rings appearing in one or more regions of the image
Broad: Scanning system defect
Narrow: Artificial pattern of colors appearing in the image; caused by light reflections between a film and platen surface due to poor film contact
Remake after re-seating the film or use an anti-Newton glass for the platen
Organics: bleed-through, print-through (acceptable) Broad: Bleed-thru from back of original
Narrow: Sticker or printing on reverse visible
Broad: Feature of original item (not a defect)
Narrow: Feature of original item (not a defect)
Although retouching might improve the image, this is generally acceptable if it accurately represents the source material
ExamplesDescriptionsAppearancesCausesRemedies
Organics: bleed-through, print-through (acceptable) Broad: Double imprint, ghost image
Narrow: Faint line next to dark line; ghost letters next to desired letters
Broad: Feature of original item (not a defect)
Narrow: Feature of original item (not a defect)
Although retouching might improve the image, this is generally acceptable if it accurately represents the source material
Organics: damaged film (acceptable) Broad: Damaged film or photograph
Narrow: Portion of image missing, light oval "dot" surrounded by dark area
Broad: Feature of original item (not a defect)
Narrow: Feature of original item (not a defect)
Although retouching might improve the image, this is generally acceptable if it accurately represents the source material
Organics: dirt in mylar enclosure (unacceptable) Broad: Unwanted elements (dirt, hair, shadows, reflections, etc.) on or next to item being imaged
Narrow: Dust and/or hair on object
Broad: Imaging setup defect
Narrow: dirt in mylar
Clean and remake
Organics: dirt on baseboard (unacceptable, acceptable) Broad: Unwanted elements (dirt, hair, shadows, reflections, etc.) on or next to item being imaged
Narrow: Dirt specks next to item being scanned
Broad: Imaging setup defect
Narrow: dirt on baseboard
Clean and remake
Organics: dirt on baseboard (unacceptable, acceptable) Broad: Unwanted elements (dirt, hair, shadows, reflections, etc.) on or next to item being imaged
Narrow: Dirt specks next to item being scanned
Broad: Imaging setup defect
Narrow: dirt on baseboard
Clean and remake
ExamplesDescriptionsAppearancesCausesRemedies
Organics: dirt on baseboard (unacceptable, acceptable) Broad: Unwanted elements (dirt, hair, shadows, reflections, etc.) on or next to item being imaged
Narrow: Dirt specks next to item being scanned
Broad: Imaging setup defect
Narrow: dirt on baseboard
Clean and remake
Organics: dirt on original (acceptable) Broad: Unwanted elements (dirt, hair, shadows, reflections, etc.) on or next to item being imaged
Narrow: dirt and smudges on object
Broad: Feature of original item (not a defect)
Narrow: Feature of original item (not a defect)
Although retouching might improve the image, this is generally acceptable if it accurately represents the source material
Organics: dot matrix printing (acceptable) Broad: Typography with wide spacing and dot pattern
Narrow: Dot matrix printing
Broad: Feature of original item (not a defect)
Narrow: Feature of original item (not a defect)
This is generally acceptable if it accurately represents the source material, some printed text may require specialized processing for improved OCR performance
Organics: double-printed (acceptable) Broad: Double or blurry image or passages within the image
Narrow: Double-printed page content
Broad: Feature of original item (not a defect)
Narrow: Feature of original item (not a defect)
Although retouching might improve the image, this is generally acceptable if it accurately represents the source material
Organics: dust on lens or sensor (unacceptable, unacceptable) Broad: Unwanted elements (dirt, hair, etc.) appearing in consecutively produced images
Narrow: Dust on lens or sensor
Broad: Imaging setup defect
Narrow: Dust in imaging system
Clear the dust and remake
ExamplesDescriptionsAppearancesCausesRemedies
Organics: fibers (unacceptable) Broad: Unwanted elements (dirt, hair, shadows, reflections, etc.) on or next to item being imaged
Narrow: White dust on photo ("negative dirt")
Broad: Imaging setup defect
Narrow: fibers in image
Clean and remake
Organics: finger (unacceptable) Broad: Unwanted elements (dirt, hair, shadows, reflections, etc.) on or next to item being imaged
Narrow: Finger holding page in image
Broad: Imaging setup defect
Narrow: finger in image
Remake without the finger
Organics: generational loss (acceptable) Broad: Faded typography
Narrow: Faded typography
Broad: Feature of original item (not a defect)
Narrow: Feature of original item (not a defect)
Although retouching might improve the image, this is generally acceptable if it accurately represents the source material
Organics: ghosting (acceptable) Broad: Double imprint, ghost image
Narrow: Faint line next to dark line; ghost letters next to desired letters
Broad: Feature of original item (not a defect)
Narrow: Feature of original item (not a defect)
Although retouching might improve the image, this is generally acceptable if it accurately represents the source material
Organics: gutter shadow (unacceptable) Broad: Unwanted elements (dirt, hair, shadows, reflections, etc.) on or next to item being imaged
Narrow: Lighting casts a shadow across the book gutter
Broad: Imaging setup defect
Narrow: angle of lights and positioning of the book contribute to gutter shadow
Remake after re-orienting the material in order to minimize the shadow
ExamplesDescriptionsAppearancesCausesRemedies
Organics: hair (unacceptable) Broad: Unwanted elements (dirt, hair, shadows, reflections, etc.) on or next to item being imaged
Narrow: Dust and/or hair on image
Broad: Imaging setup defect
Narrow: hair in image
Clean and remake
Organics: hair (unacceptable) Broad: Unwanted elements (dirt, hair, shadows, reflections, etc.) on or next to item being imaged
Narrow: Dust and/or hair on image
Broad: Imaging setup defect
Narrow: hair in image
Clean and remake
Organics: insect (unacceptable) Broad: Unwanted elements (dirt, hair, shadows, reflections, etc.) on or next to item being imaged
Narrow: squashed insect on image
Broad: Imaging setup defect
Narrow: insect in image
Consult with conservation as needed; clean and remake
Organics: irregular typeface (acceptable) Broad: Unique Typography, graphics, and tabular content
Narrow: Unique Typography used for newspaper headlines
Broad: Feature of original item (not a defect)
Narrow: Feature of original item (not a defect)
This is generally acceptable if it accurately represents the source material, but it will likely impact OCR performance
Organics: irregular typeface and graphic and tabular content (acceptable) Broad: Unique Typography, graphics, and tabular content
Narrow: Unique Typography and graphics used for newspaper advertisements
Broad: Feature of original item (not a defect)
Narrow: Feature of original item (not a defect)
This is generally acceptable if it accurately represents the source material, but it will likely impact OCR performance
ExamplesDescriptionsAppearancesCausesRemedies
Organics: motion blur (acceptable) Broad: Blurry image or passages within the photograph
Narrow: Moving objects appear blurry in the photograph
Broad: Feature of original item (not a defect)
Narrow: Feature of original item; long exposure (not a defect)
This is generally acceptable if it accurately represents the source material
Organics: notation (acceptable) Broad: Typography with script notation
Narrow: Handwritten notation obscures or competes with text
Broad: Feature of original item (not a defect)
Narrow: Feature of original item (not a defect)
This is generally acceptable if it accurately represents the source material, but it will likely impact OCR performance
Organics: reflections (unacceptable) Broad: Unwanted elements (dirt, hair, shadows, reflections, etc.) on or next to item being imaged
Narrow: Reflection visible in dark tones of photograph and background
Broad: Imaging setup defect
Narrow: Light tones are reflected in coping glass or glossy materials
Mask/cover or remove the reflected items and remake
Organics: reflections (unacceptable) Broad: Unwanted elements (dirt, hair, shadows, reflections, etc.) on or next to item being imaged
Narrow: Reflections visible in curled portions of poster
Broad: Imaging setup defect
Narrow: Light tones are reflected in coping glass or glossy materials
Flatten materials, mask any reflected items, and polarize or reposition light sources
Organics: reflections (unacceptable) Broad: Unwanted elements (dirt, hair, shadows, reflections, etc.) on or next to item being imaged
Narrow: Reflections and texture of lamination laterial visible in dark tones
Broad: Imaging setup defect
Narrow: Light tones are reflected in coping glass or glossy materials
Flatten materials, mask any reflected items, and polarize or reposition light sources
ExamplesDescriptionsAppearancesCausesRemedies
Organics: scratch (unacceptable) Broad: Unwanted elements (dirt, hair, shadows, reflections, etc.) on or next to item being imaged
Narrow: Scratch on image
Broad: Imaging setup defect
Narrow: scratches in coping glass or scanner platen are visible in the image
Check the original, then replace the glass and remake
Organics: shadow (unacceptable) Broad: Unwanted elements (dirt, hair, shadows, reflections, etc.) on or next to item being imaged
Narrow: Shadow cast into image
Broad: Imaging setup defect
Narrow: An object near the content cast a shadow during photograhy
Clear the space between the light source and source materials and remake
Organics: stained film (acceptable) Broad: Areas of uneven tonality or blotches in a film scan
Narrow: Chemical stains or residue on film
Broad: Feature of original item (not a defect)
Narrow: Feature of original item (not a defect)
Although retouching might improve the image, this is generally acceptable if it accurately represents the source material
Organics: watermark or imprint (acceptable) Broad: Image or pattern showing through page content
Narrow: Watermark showing
Broad: Feature of original item (not a defect)
Narrow: Feature of original item (not a defect)
Backing the page with a dark color may reduce the impact of the watermark, especially for translucent papers. This is generally acceptable if it accurately represents the source material, but it will likely impact OCR performance
Organics: watermark or imprint (acceptable) Broad: Image or pattern showing through page content
Narrow: Imprint showing
Broad: Feature of original item (not a defect)
Narrow: Feature of original item (not a defect)
Backing the page with a dark color may reduce the impact of the watermark, especially for translucent papers. This is generally acceptable if it accurately represents the source material, but it will likely impact OCR performance
ExamplesDescriptionsAppearancesCausesRemedies
Readability: focus (acceptable) Broad: Blurry or soft focus image
Narrow: Image is not in-focus
Broad: Feature of original item (not a defect)
Narrow: Feature of original item (not a defect)
This is generally acceptable if it accurately represents the source material
Readability: focus (acceptable, unacceptable) Broad: Blurry or soft-looking image when viewed in browser, but sharp-looking when viewed with editing program
Narrow: Image is in-focus, but browser software displays them as blurry
Broad: Software error
Narrow: File browser software does not faithfully display the image files
Review image files using reliable software tools such as Adobe Photoshop, Irfanview, Adobe Photoshop Lightroom, etc.
Readability: focus (acceptable, unacceptable) Broad: Blurry or soft focus image when viewed with several reliable programs
Narrow: Image is not in-focus
Broad: Not software error - source materials were photographed slightly out-of-focus
Narrow: Software reliably displays image files
If images do not pass with judicious sharpening, adjust camera focus and remake
Readability: focus (acceptable, unacceptable) Broad: Blurry or soft focus image when viewed with several reliable programs
Narrow: Image is not in-focus
Broad: Not software error - source materials were photographed slightly out-of-focus
Narrow: Software reliably displays image files
If images do not pass with judicious sharpening, adjust camera focus and remake
Readability: focus (acceptable, unacceptable) Broad: Blurry or soft focus image when viewed with several reliable programs
Narrow: Image is not in-focus
Broad: Not software error - source materials were photographed slightly out-of-focus
Narrow: Software reliably displays image files
If images do not pass with judicious sharpening, adjust camera focus and remake
ExamplesDescriptionsAppearancesCausesRemedies
Readability: focus (unacceptable) Broad: Blurry or soft focus image. Film grain appears soft
Narrow: Image is not in-focus
Broad: Imaging setup defect
Narrow: Camera or scanner is out-of-focus
Adjust camera focus or repair scanner and remake
Readability: focus (unacceptable) Broad: Blurry or soft focus image. Film grain appears soft
Narrow: Image is not in-focus
Broad: Imaging setup defect
Narrow: Camera or scanner is out-of-focus
Adjust camera focus or repair scanner and remake
Readability: focus (marginally acceptable) Broad: Blurry or soft focus image. Film grain appears soft
Narrow: Image is not in-focus
Broad: Imaging setup defect
Narrow: Camera or scanner is out-of-focus
If images do not pass with judicious sharpening, adjust camera focus and remake
Readability: focus (unacceptable, acceptable) Broad: Blurry or soft focus image
Narrow: Image is not in-focus
Broad: Imaging setup defect
Narrow: Camera or scanner is out-of-focus
Adjust camera focus or repair scanner and remake
Readability: focus (unacceptable, acceptable) Broad: Blurry or soft focus image
Narrow: Image is not in-focus
Broad: Imaging setup defect
Narrow: Camera or scanner is out-of-focus
Adjust camera focus or repair scanner and remake
ExamplesDescriptionsAppearancesCausesRemedies
Readability: focus (unacceptable, acceptable) Broad: Blurry or soft focus image
Narrow: Image is not in-focus
Broad: Imaging setup defect
Narrow: Camera or scanner is out-of-focus
Adjust camera focus or repair scanner and remake
Readability: focus for microfilm scans (unacceptable, acceptable) Broad: Blurry or soft focus image
Narrow: Image is not in-focus
Broad: Imaging setup defect
Narrow: Scanner is out-of-focus
Adjust camera focus or repair scanner and remake
Readability: insufficient pixels per inch (PPI) (sample frequency) (unacceptable) Broad: Loss of information
Narrow: Fine details appear blurry or are lost (pinstriping in sleeve)
Broad: Imaging setup defect
Narrow: Scanner resolution/PPI set too low (2800PPI)
Adjust and remake at higher PPI (4000PPI)
Readability: insufficient pixels per inch (PPI) (sample frequency) (unacceptable) Broad: Blurry or soft focus image
Narrow: Image is not in-focus
Broad: Imaging setup defect
Narrow: Scanner resolution/PPI set too low
Adjust and remake at higher PPI
Readability: insufficient pixels per inch (PPI) (sample frequency) (unacceptable) Broad: Blurry or soft focus image
Narrow: Image is not in-focus
Broad: Imaging setup defect
Narrow: Scanner resolution/PPI set too low
Adjust and remake at higher PPI
ExamplesDescriptionsAppearancesCausesRemedies
Skew: anamorphosis, lens distortion (unacceptable) Broad: Image distortion
Narrow: Image is rhomboidal or stretched
Broad: Imaging setup defect
Narrow: Source materials were not flat or in-plane with the camera. The wide angle lens also adds barrel distortion. These defects will have a significant impact on OCR accuracy
Although software deskew can improve the image, better results often require re-making after adjusting camera configuration
Skew: keystoning, lens distortion (unacceptable) Broad: Image distortion
Narrow: Image tapers or narrows at one or more sides
Broad: Imaging setup defect
Narrow: Source materials were not flat or in-plane with the camera. The wide angle lens also adds barrel distortion. These defects will have a significant impact on OCR accuracy
Change lens and/or reposition camera and source material and remake
Skew: keystoning, lens distortion (unacceptable) Broad: Image distortion
Narrow: Image tapers or narrows at one or more sides
Broad: Imaging setup defect
Narrow: Source materials were not flat or in-plane with the camera. The wide angle lens also adds barrel distortion. These defects will have a significant impact on OCR accuracy
Change lens and/or reposition camera and source material and remake
Skew: keystoning, lens distortion (unacceptable) Broad: Image distortion
Narrow: Image tapers or narrows at one or more sides
Broad: Imaging setup defect
Narrow: Source materials were not flat or in-plane with the camera. The wide angle lens also adds barrel distortion. These defects will have a significant impact on OCR accuracy
Change lens and/or reposition camera and source material and remake
Skew: scanned microfilm image distortion (unacceptable) Broad: Image distortion
Narrow: Image appears rhomboidal
Broad: Imaging setup defect
Narrow: Microfilm scanner speed settings are too high. These defects will have a significant impact on OCR accuracy
Although software de-skew can improve the image, better results often require re-scanning after adjusting scan speed
ExamplesDescriptionsAppearancesCausesRemedies
Skew/orientation: page not straight (unacceptable) Broad: Content not square with image frame
Narrow: Content not square with image frame
Broad: Imaging setup defect
Narrow: Source materials were not square when imaged
Rotate image in editing program or remake after repositioning the materials
Skew/orientation: page not straight (unacceptable) Broad: Content not square with image frame
Narrow: Content not square with image frame
Broad: Imaging setup defect
Narrow: Source materials were not square when imaged
Rotate image in editing program or remake after repositioning the materials
Skew/orientation: page upside down (unacceptable) Broad: Image appears upside down
Narrow: Image in wrong orientation
Broad: Imaging setup defect
Narrow: Original imaged in wrong orientation
Rotate image in editing program or remake after repositioning the materials
Sharpening: over-sharpened (unacceptable) Broad: Halos and/or exaggerated contrast
Narrow: Image artificially over-sharpened
Broad: Imaging system defect
Narrow: Raw file processing error or excessive post-processing (unsharp masking)
Adjust processing or editing settings and remake from RAW
Sharpening: over-sharpened (unacceptable) Broad: Halos and/or exaggerated contrast
Narrow: Image artificially over-sharpened
Broad: Imaging system defect
Narrow: Raw file processing error or excessive post-processing (unsharp masking)
Adjust processing or editing settings and remake from RAW
ExamplesDescriptionsAppearancesCausesRemedies
Sharpening: over-sharpened (unacceptable) Broad: Halos and/or exaggerated contrast
Narrow: Image artificially over-sharpened
Broad: Imaging system defect
Narrow: Raw file processing error or excessive post-processing (unsharp masking)
Adjust processing or editing settings and remake from RAW
Stitching defects: folds and misalignment in source material (acceptable) Broad: Defect on a line or a small number of lines
Narrow: Misalignment of line or text features
Broad: Feature of original item (not a defect)
Narrow: Feature of original item (not a defect)
This is generally acceptable if it accurately represents the source material
Stitching defects: tile misalignments (unacceptable) Broad: Defect on a line or a small number of lines
Narrow: Misalignment of line, edge, or text features
Broad: Imaging setup defect
Narrow: Post-processing error (stitching) caused by photographic distortions or excessive or insufficient tile overlap
Change lens, and/or level sensor, lens, and object planes, and remake tile images with sufficient overlap
Stitching defects: tile misalignments (unacceptable) Broad: Defect on a line or a small number of lines
Narrow: Misalignment of line, edge, or text features
Broad: Imaging setup defect
Narrow: Post-processing error (stitching) caused by photographic distortions or excessive or insufficient tile overlap
Change lens, and/or level sensor, lens, and object planes, and remake tile images with sufficient overlap
Stitching defects: tile misalignments (unacceptable) Broad: Defect on a line or a small number of lines
Narrow: Misalignment of line, edge, or text features
Broad: Imaging setup defect
Narrow: Post-processing error (stitching) caused by photographic distortions or excessive or insufficient tile overlap
Change lens, and/or level sensor, lens, and object planes, and remake tile images with sufficient overlap
ExamplesDescriptionsAppearancesCausesRemedies
Tonality: too much contrast, channel clipping (unacceptable, acceptable) Broad: High contrast image; loss of information in dark values
Narrow: Poor tonal mapping and loss of information in low and/or high values
Broad: Imaging setup defect
Narrow: Poor lighting or RAW processing
Diagnose and calibrate the imaging and/or processing system before remaking the image file
Tonality: too much contrast, channel clipping (unacceptable, acceptable) Broad: High contrast image; loss of information in dark values
Narrow: Poor tonal mapping and loss of information in low and/or high values
Broad: Imaging setup defect
Narrow: Poor lighting or RAW processing
Diagnose and calibrate the imaging and/or processing system before remaking the image file
Tonality: too much contrast, channel clipping (unacceptable, acceptable) Broad: High contrast image; loss of information in dark values
Narrow: Poor tonal mapping and loss of information in low and/or high values
Broad: Imaging setup defect
Narrow: Poor lighting or RAW processing
Diagnose and calibrate the imaging and/or processing system before remaking the image file
Tonality: over-exposure, clipping (unacceptable, acceptable) Broad: Light image. Faded typography; loss of information in light values
Narrow: Image overexposed or incorrectly processed
Broad: Imaging system defect
Narrow: Incorrect exposure settings used, raw file processing error or poorly made gain or LCC file
Diagnose and tune the processing system or re-create the gain file before remaking the image file
Tonality: over-exposure, clipping (unacceptable) Broad: High contrast image. Faded details and blocked dark tones; loss of information in light values
Narrow: Image incorectly processed
Broad: Imaging system defect
Narrow: Incorrect exposure settings used, raw file processing error or poorly made gain or LCC file
Diagnose and tune the processing system or re-create the gain file before remaking the image file
ExamplesDescriptionsAppearancesCausesRemedies
Tonality: under-exposure, posterization (unacceptable, acceptable) Broad: Abrupt changes in or exaggerated color or tonal gradation. Loss of information in light or dark values
Narrow: Banding, color or tonal posterization
Broad: Imaging system defect
Narrow: Raw file processing error or poorly made gain or LCC file
Diagnose and tune the processing system or re-create the gain file before remaking the image file
Tonality: under-exposure, posterization (unacceptable, acceptable) Broad: Abrupt changes in or exaggerated color or tonal gradation. Loss of information in light or dark values
Narrow: Banding, color or tonal posterization
Broad: Imaging system defect
Narrow: Raw file processing error or poorly made gain or LCC file
Diagnose and tune the processing system or re-create the gain file before remaking the image file
Tonality: under-exposure, clipping (unacceptable, acceptable) Broad: Dark image; loss of information in dark values
Narrow: Image underexposed or incorrectly processed
Broad: Imaging system defect
Narrow: Incorrect exposure settings used, raw file processing error or poorly made gain or LCC file
Diagnose and tune the processing system or re-create the gain file before remaking the image file

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