Xerox® DocuMate® 4799 and 4790 | Performance and Image Quality |
Note
In order to simulate grayscale (8 bits per pixel), the Reference Scanner captures halftone images at 1 bit per pixel (black and white) and renders them using halftone screening at different frequencies (lpi – lines per inch) based on the content of the document (fine or course halftone) versus the Xerox DocuMate 4799, which renders a grayscale image at 8 bits per pixel. As a result, the Xerox DocuMate 4799 is capable of reproducing images that more closely approximate the original document
The captured digital images were then compared to equivalent scans (digital images) obtained from the Reference Scanner, which served as the baseline, or reference for comparison. The results of this comparison have been documented below. All scans were captured independent of applying image enhancement software, which might otherwise improve or enhance the appearance of the images during or
Image Quality Evaluation1
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| Xerox DocuMate 4799 |
| Assessment |
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| Black and White |
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| Better reproduction (clarity) of fine text and | |
| Scans the image bi- |
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| line art compared to the Reference Scanner | |
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| Not suitable for reproducing grayscale or | ||
| tonal, where everything |
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| on the page is either |
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| color graphics | |
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| black or white |
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| Grayscale |
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| Good overall reproduction of shades of | |
| Scans the image using |
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| gray – variations from black at the weakest | |
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| intensity to white at the strongest, and Tonal | ||
| varying shades of gray | |
| Reproduction Curve (TRC) – luminance, or | |
| to reproduce the |
| brightness of the image, compared to the | ||
| document |
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| Reference Scanner | |
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| May experience Moiré (interference pattern |
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| or artifact) in certain images |
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| Color |
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| Acceptable overall reproduction of color | |
| Scans the image in color, |
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| (color depth/balance), especially in highlight | |
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| areas compared to the Reference Scanner | ||
| creating a full color copy |
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| Acceptable Tonal Reproduction Curve (TRC) | |
| of an original document |
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| – graduations of Cyan, Magenta, Yellow or | ||
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| Black (CMYK) from 0 |
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| the Reference Scanner | |
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| Good reproduction (color and clarity) of fine |
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| lines and color text compared to the |
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| Reference Scanner |
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| Light color text on light backgrounds may |
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| appear fuzzy in certain color combinations |
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| Overall |
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Fair Good Very Good
1Compared to equivalent scans from the Reference Scanner
Performance and Image Quality Expectations Guide |
