Xerox Documate 3640 User Guide

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Image Enhancements
Click on the Image Enhancements icon to select options applicable to what type of image processing 
you want applied for the items being scanned.
•
Main panel —this panel contains the most commonly used scan settings. Some of the options in 
this panel may have adjustment options on th e other panels in this section. When the Basic 
source configuration mode is selected, this is the only panel available. Change to the  Advanced 
source configuration mode to enable the other pa nels which are also described in this section.
• Color processing panel —this panel contains advanced options for processing colors in the final 
scans.
• Advanced panel —this panel contains advanced image  enhancement options for improving the 
clarity of the scanned image. 
The  Image enhancements  section when the Basic document source configuration mode is selected.
The  Image enhancements  section when the Advanced document source configuration mode is 
selected. 
						

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Disabled Options in this Section
Some options in the interface may be grayed out an
d cannot be selected. Grayed out options are either 
not appropriate for the current scanner, the software  needed to enable the feature is not installed, 
or 
the feature is dependent on another setting in the  scanner's interface. Hover the mouse cursor over a 
grayed out feature to see information  about why the feature is unavailable.
When you are using a scanner that has multiple sources, such as an ADF with Flatbed combination 
scanner, some options may be disabled based on th e current source displayed in the source list. For 
example when the flatbed source is selected, the manual feed option will be disabled.  
If an option is unavailable, check to see which source is displayed at the top of the source list when in 
the Advanced interface view.
Note that even when  Sources identical is selected, any options that are only available for a specific 
source will be discarded if the scanner scans from the source that does not have those options.
When Flatbed is displayed here, only the 
options that can be used for the flatbed will 
be available in the scanner interface. Click on one of the color modes under the 
source you want to configure.  That source will 
now be displayed at the top of the list, and 
the options for that source will be available in 
the scanner interface. 
						

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Main Panel Options
Some of the options in this panel 
may have advanced adjustment opti ons on a different panel in this 
section. When the  Advanced configuration mode is selected, an icon will appear  next to those features 
which have adjustment options on  another tab. Click on one of the icons to go to the area of the 
interface where the adjustment options are located.
Click on a link below to go to the appropriate page in this section for instructions on adjusting the 
option that is displayed on the  Main tab.
See Advanced Panel Options on page 181
•Despeckle
Brightness
Brightness is the overall lightness of the image. Move  the slider left or right to darken or lighten the 
image. Adjusting the brightness level adjusts the tone  of the pixels, without changing the true color of 
the pixels; such as when adjusting hue. 
Choosing brightness values
Adjusting the brightness level is based on how you  want the image to appear and there is no standard 
to adhere to. Below are some recommended option s for brightness image correction based on the 
original document quality.
• Original documents of good quality - 50%
• Pencil written letters, forms, or drawings - 25% to 40%
• Faded pictures or old documents with faded text - 35% to 45%
• Light colored carbon copy paper, such as yellow or  pale pink or pale green, with light text - 45% to 
55%
• Newspaper or magazine pages - 55% to 70%
• Book pages - 55% to 80%
• Pictures taken inside or in the shade - 60% to 85% 
						

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Brightness
 works in conjunction with  Contrast for image enhancement. When you are adjusting the 
brightness level to improve the scanned image quality, try adjusting the contrast level as well. The 
contrast level is the range between the lightest and  darkest parts of the image. For example, if you 
scanned a document with notes written in pencil, you may have to decrease the brightness level to get 
the handwritten notes to appear in the scanned image. However, when decreasing the brightness, 
white starts to appear gray in the  image. In that case, raise the contrast level to make the differences 
between the lightest and darkest part of the image more defined.
Color image brightness examples
The examples below show the original image at the default setting of 50% brightness level, 25% 
brightness and 75% brightness. Adjusting the bright ness level does not make the image completely 
black nor completely white.
Technical note:
Most monitors have a brightness setting that is  user adjustable. When viewing scanned images on-
screen, versus printing the image,  the brightness setting of the monitor may affect how light or dark 
the scanned image looks when compared to the original . If the scanned image is too different from the 
original image, or if adjusting the scanned brightness level does not modify the image how you want, 
try adjusting the monitor's brightness level. Refe r to the monitor's user guide for adjusting the 
brightness level and see if the manufacturer has any recommended settings.
Black background scanners:
Some scanners have a black background plate. A bl ack background results in more precise cropping 
results and skew detection. However, when scanning  thin paper, such as multipart color forms or ruled 
writing paper, which are less than 18lb paper we ight, the background may “bleed” through into the 
final image and make the image darker than it shou ld be. In that case, try adjusting the brightness 
level between 60% and 80%.
Contrast
Contrast refers to the differences between the light an d dark portions in the image. Move the slider left 
or right to decrease or increase the contrast le vels. Increasing the contrast level emphasizes the 
difference between the lighter and darker portions of the image, decreasing the contrast de-
emphasizes that difference.
Brightness: 25% Brightness: 50% Brightness: 75% 
						

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Choosing contrast values
While 
Brightness  adds the same amount of gray or  white to all pixels in the image, Contrast  adjusts 
the pixels based on the pixel color level. For instance, increasing the contrast level will add white to light 
colored pixels and gray to dark pixels to make the  difference between color levels in the image crisper. 
Decreasing the contrast level will have the opposite  affect, where light colored pixels are modified with 
gray and dark pixels are modified with white to make the transition of colors in the image appear 
smoother.
Adjusting the contrast level is based on how you want the image to appear and there is no standard to 
adhere to. Contrast works in conj unction with brightness for image en hancement, when decreasing the 
brightness level, the overall image becomes darker, in which case you may want to increase the 
contrast level so that the differences between the lighter and darker portions of the image are clearer.
Below are some recommended options for contrast im age correction based on the original document 
quality.
• Original documents of good quality - 50%
• Pencil written letters, forms, or drawings - 55% to 65%
• Faded pictures or old documents with faded text - 60% to 70%
• Light colored carbon copy paper, such as yellow or  pale pink or pale green, with light text - 45% to 
55%
• Newspaper or magazine pages - 55% to 70%
• Book pages - 60% to 75%
• Pictures taken inside or in the shade - 40% to 60%
Color image contrast examples
The examples below show the original image at the default setting of 50% contrast level, 25% 
contrast and 75% contrast.
Technical note:
Most monitors have a contrast setting that is  user adjustable. When viewing scanned images on-
screen, versus printing the image, the contrast se tting of the monitor may affect how clear a scanned 
image looks when compared to the original. If the  scanned image is too different from the original 
image, or if adjusting the scanned contrast level does not modify the image how you want, try 
adjusting the monitor's contrast level. Refer to the  monitor's user guide for adjusting the contrast level 
and see if the manufacturer has any recommended settings.
Contrast: 25% Contrast: 50% Contrast: 75% 
						

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Black background scanners:
Some scanners have a black background plate. A bl
ack background results in more precise cropping 
results and skew detection. However, when scanning  thin paper, such as carbon copy paper or ruled 
writing paper, which are less than 18lb paper we ight, the background may “bleed” through into the 
final image and make the image darker than it shou ld be. In that case, try adjusting the brightness 
level between 40% and 60%, then adjust the contrast level between 60% and 80%. 
Gamma
Gamma is the tone curve and starting point for imag e enhancement. Move the slider left or right to 
darken or lighten the image. As you raise or lower the  Gamma value, the values at which  Brightness 
and  Contrast  affect the image are changed. It is recommended that you keep the default gamma 
value, or adjust this setting before adjusting the other options. 
Choosing gamma values
As the gamma value is adjusted lower, the tone cu rve begins to straighten and the shadows of the 
image are expanded, darkening the shadows without  overall darkening the image with gray as seen 
with lowering the brightness level. This way, th e highlights and shadows in the image are maintained 
by saturating the pixels with darker levels of the  same color rather than adding gray to all colors.
As the gamma value is adjusted higher, the tone  curve bends and the highlights of the image are 
expanded, lightening the highlights without overall lightening the image with white as seen with 
raising the brightness level. This way, the highlights and shadows in the image are maintained by 
saturating the pixels with lighter levels of the same color rather than just adding white.
Adjusting the gamma level is based on how you want  the image to appear and there is no standard to 
adhere to.
Color image gamma examples
The examples below show the original image at the default setting of 1.8 gamma level, then 1.0 
gamma and 2.6 gamma. Adjusting the gamma level does not make the image completely black nor 
completely white.
Gamma: 1.0 Gamma: 1.8 Gamma: 2.6 
						

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Technical note:
Most monitors have a gamma setting that is user adjustable. When viewing scanned images on-screen, 
versus printing the image, the gamma setting of th
e monitor may affect how light or dark the scanned 
image looks when compared to the original. If the  scanned image is too different from the original 
image, or if adjusting the scanned gamma level does not modify the image how you want, try 
adjusting the monitor's gamma level. Refer to the  monitor's user guide for adjusting the gamma level 
and see if the manufacturer has any recommended settings.
Invert Image
The  Invert image  option reverses the color of each pixel in the scanned image. 
When scanning in black and white, each pixel is reversed from black to white and white to black. When 
scanning in grayscale each pixel is reversed to the opposite level of gray. When scanning in color each 
pixel is reversed to the oppo site color in the color wheel.
For example, you might choose this option if you  are scanning pages that have been printed from 
newspaper microfilm. Newspaper microfilm reverses  black and white so that when viewed on a 
monitor, the text is white and the paper is black.
The following example shows the original  grayscale image and the inverted image.
The following example shows the original color image and the inverted image.  
						

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Mirror Image
The 
Mirror image  option flips the image left-to-right.
Bit Depth Reduction
The Bit depth reduction  options are only available when scanning in black and white. Click the drop 
down menu and select an option from the list.
Threshold and Dynamic threshold
Threshold  enables you to set what level of light or dark to look for on a page. When scanning in black 
and white, everything on the page is set to either white pixels or black pixels in the final image. If the 
text on the page is a light color, then the text may be gone in the final image as the scanner will 
change those light colors to white  pixels. The threshold slider lets you set the level of darkness or 
lightness of the text on the page.  Dynamic threshold attempts to evaluate the image and dynamically 
adjust the threshold level. These options work best  for documents that contain only text such as 
business letters, spreadsheets, reports, etc...
• Threshold —move the slider to the left or right to se t the level of lightness or darkness for the 
scanner to leverage from. 
For example, if you are scanning a document with  gray text, such as hand written pencil notes, 
move the slider to the right. This tells the scanner that the level to look for is light, and gray pixels 
are converted to black pixels instead of white. If  the overall tone of the original document is dark, 
such as a colored background that may interfere wi th detecting black, move the slider left. This 
tells the scanner that the level to look for is dark,  only very dark areas such as text are converted to 
black pixels.
If you are scanning documents that are in good condition, with black text on a white background, 
the default threshold option will properly scan the item. This level only needs to be adjusted if the 
scanned image does not have image clarity similar to the original.
• Sensitivity —move the slider left or right to adjust th e sensitivity level for dynamic thresholding. 
This slider is only enabled when  Dynamic threshold is selected in the list. 
						

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Error diffusion, Bayer, and Halftone pattern
Error diffusion
, Bayer , and Halftone patterns  are the intentional applicat ion of noise (dithering) in 
the image to help alleviate banding when scanning in  binary (black and white) mode. For example, if 
you scan a color photo in black and white, the image file will have large blocks of black and white and 
the image barely recognizable. Dithering the image creates a black and white image that is 
recognizable. 
Below is an example of a color scan, a black and white scan without dithering, and a black and white 
scan with dithering. When the image is scaled down, it may look like a grayscale scan. When the image 
is at normal size or enlarged you will be able to  clearly see the dithering pattern, as shown in the close-
up image.
Bayer dither scan - Close up
Fill Margin Holes
Select this option if you are scanning pages with pu nched holes in the margins. This option will fill 
these holes with the detected background color in the final scan.  The scanner will detect and fill the 
holes under the following conditions:
• The size of the hole can be between approximately 4 mm and 12 mm
• The maximum width of the margin is 25.4 mm from the edge of the paper
• The size of the margin is 24.4 mm
Color scan Black and White scan Bayer dither scan 
						

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• The position of the hole cannot be flush to th
e edge of the margin area and it cannot overlap the 
edge of the margin area
Color Processing Panel Options
The options in this panel are for setting how the scanner should process colors in specific color modes.
Color Dropout
Color dropout  tells the scanner and software to remove a specific color from the image. You can 
choose either  Red, Green , or Blue , or define a custom color, to be dropped out of an image. 
To input a custom color us ing its RGB value, select Custom in this list and then input the values for R, G, 
and B in their appropriate boxes, where R, G, and B are numbers from 0 to 255. 
To l e r a n c e —use the slider to adjust the  precision of the color dropout. 
• More precise—this option removes a range of colors clos est to the pure color selected or defined 
in the custom fields. For example, pure red has an R/G/B value of 255/0/0. Selecting Red indicates 
that the scanner should look for a range of RGB reds close to pure red and remove them from the 
image.