This item is available on the New Document dialog box and the Select Document dialog box. It selects the method of processing the grayscale data in an image to try to choose the best grayscale level to set as the largest grayscale value which is left unchanged in a grayscale clip or full page image on the image for the top or bottom of the sheet. These values are known as the Top and Bottom Upper Grayscale Filters.
All pixels with values greater than this Upper Grayscale Filter are set to the same value to clean up the background and increase compressibility. The Upper Grayscale Filter is chosen such that the maximum undesirable background is removed while preserving all the good image data.
This Dynamic Threshold type method also governs the way the bitone level is chosen, since the bitone level is referenced from the grayscale level. The method by which the bitone point is referenced is also determined by the Dynamic Threshold type.
|
Top Side Dynamic Threshold Type |
Sets the Dynamic Threshold Type - Document/Sheet Level used on the image for the top of the sheet. |
|
Bottom Side Dynamic Threshold Type |
Sets the Dynamic Threshold Type - Document/Sheet Level used on the image for the bottom of the sheet. |
There are four different possible methods of accomplishing these two things.
Paper Eliminating Dynamic Threshold Standard Deviation allows setting of the value used by the Paper Eliminating Dynamic Threshold Type - Document/Sheet Level to determine how much of the grayscale range representing paper (in 0.1 standard deviation units) to eliminate when setting the Top and/or Bottom Upper Grayscale Filters on the image for the top and/or bottom of the sheet. This control is enabled only when either the top or bottom Dynamic Threshold Type is set to Paper Eliminating. The value set by this control applies to both the top and bottom images.
TIP: Making this value larger will clean up more of the background and achieve better compression but might remove valuable image data. Making this value smaller may help keep light image data but might produce an image with a dirtier background and cause a less compressible image.
|
See Help on Help for additional information on using this help file. See Scantron Technical Support for additional information on technical support and training options. See the ScanTools Suite System Requirements for further details on hardware and software requirements. ScanTools is a suite of products; the specific information you want may appear in the help for a different module. If you don't find what you're looking for here, try one of the following:
|
Scantron Corporation
Customer Service (forms, products, and services): 1-800-SCANTRON (722-6876) Technical Support: 1-800-445-3141 |
|
|
Copyright © 1998-2012 Scantron Corporation. All rights reserved. Use permitted only under license. www.scantron.com. No part of the Help or user guides may be reproduced in any form, or by any means, without express permission from Scantron Corporation. LINKS TO THIRD PARTY SITES This help system may contain links to third party websites ("Linked Sites"). The Linked Sites are not under the control of Scantron and Scantron is not responsible for the content of any Linked Site, including without limitation any link contained in a Linked Site or any changes or modifications to a Linked Site. Scantron is not responsible for web casting or any other form of transmission received from any Linked Site. Scantron provides Users with the ability to link the Assessment System to the Linked Sites as a convenience to you, and the inclusion of any link does not imply endorsement by Scantron of the Linked Site or any association with its operators. |
||
Normal