Xerox DocuMate 152i, Scanning Manual

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TWAIN Scanning Guide Document Settings
30 User’s Guide
Compress transfers
Select this option to have the scanner compress the image in Gray and Color scans. This reduces
the file size and allows for faster image transfer from the scanner to the computer. Once the
compressed image is on the computer, the scanner’s driver will then uncompress the image, and
perform any image processing functions that have been selected in the scanning interface. The
uncompressed image is then transferred to the scanning application. With Compress transfers, a
scanning application such as Nuance PDF Converter, will receive the uncompressed image and
save the image in whatever file format it uses. You can use the Quality slider to adjust the level of
compression you want to use.
Quality
You can fine tune the compression level by adjusting the quality slider between high compression
and high quality. When the quality level is set to high compression, the scanner will scan and
transfer images faster than high quality, but the image quality of the output scan will be lower.
Subsampling
The subsampling options allow you to select the encoding ratio between color information and
luminosity. Subsampling works by lowering the resolution of the RGB colors found in an image
without effecting luminescence of the image. This compresses the image to create smaller file
sizes but it can sometimes result in loss of image quality. Depending on the type of image being
scanned, subsampling encoding may not have a noticeable effect in the final image file. You
should try test scans using the different levels of subsampling to make sure you are happy with the
image quality.
• 4:4:4 —no subsampling and the ratio between color and luminosity remains unchanged.
• 4:2:2 —mid-level ratio between color and luminosity.
• 4:1:1 —highest ratio difference between color and luminosity, which results in saving the
smallest file size.
Compression
This option is specific compression for file and memory transfers to an application. It is only
available if the application you are using can accept a compressed image file. For instance, if your
scanning application is set to receive JPEG compressed images, then the
Compression field will
display JPEG . Otherwise, the status for Compression will always be disabled and display
Uncompressed because the scanning application you are using is requesting an uncompressed
image.
When this option is available, it is an advanced user and application option and should not be
adjusted if you are not familiar with the technology. However, if you are certain that you are using
an application that can receive a compressed image, and you want to be able to change the
image compression type, you will need to enable user adjustable compression in the scanning
interface. Please refer to the “Driver Settings” section for instructions.
Please note that if you adjust this setting, and the application cannot actually accept the option
you change, the scanning interface and the application may crash. It is
highly recommended that
you leave the default options and let the application set any image compression.
From the Windows Control Panel
1. Click on the Driver settings tab.