Clip Definition - Requirements and Considerations

Image clips require that the ScanTools Plus application definition have the Add Image Header Fields menu item turned on. This must be enabled for any ScanTools Plus application that will use image clipping with ScanTools Plus Link. You must open the ScanTools Plus application, use the Output menu, select Add Image Header Fields, and save the application. If the application has profiles, the profiles must be recreated. For details see: Image Header Fields - ScanTools Plus Application Definition

You can implement image clip definition in one of the following ways:

• ScanTools Plus Application Definition (.sds.StxAppDef file)
• Solution Program – ClipHelper Interface Summary of ScanTools Plus Link provides same control as ScanTools Plus application does, but offers greater flexibility and robustness.
• Combination of the ScanTools Plus application definition and the solution program

Before you determine which method(s) to implement, consider the aspects of an image clip that need to be defined. All the characteristics of a clip can be handled by the ScanTools Plus application definition or the ClipHelper interface with the ClipRegion structure for location and the ClipAttributes structure for characteristics, which also includes a ClipRegion.

• Location – any place on the form vs. timing mark read cell location. The ClipHelper properties allow you to define any place on the form using a ClipRegion structure. The ScanTools Plus application definition limits you to the OMR coordinates of timing marks and read cells ( x and y axis of the scanner).
• Characteristics – physical attributes important for viewing and storing
• Depth – bitone or grayscale

Bitone, additional features of Bitone Edge Contrast Enhancement, Bitone Threshold Type, Manual Bitone Threshold

• Grayscale – additional feature of Background Offset needed, if so Offset number to use
• Compression – ScanTools Plus definition requires compression of some type, ClipHelper allows no compression in addition to the types supported by ScanTools Plus.

NOTE: The ScanTools Plus application definition default values for image clips Depth and Compression is 256 Grayscale with G4Fax compression. This was originally implemented for performance on a 5000i scanner, but is not compatible with most standard image viewers. This means using the ScanTools Plus default values is not optimal. For recommendations see ClipHelper.ClipDepth property

• Rotation – ScanTools Plus definition allows for specifying rotation, but rotation does NOT occur at scan time with ScanTools Plus software; the clip is stored in the ScanTools Plus master TIFF file unrotated. ScanTools Plus image archiving and/or editing is the point when the clip can be viewed as rotated. ClipHelper provides rotation that is implemented as the clip is written to a stream or file.
• Background Form added – similar to rotation, ScanTools Plus software does not combine the background form image for viewing until archiving or post-scan editing occurs. ClipHelper combines the background form as the clip is written to a strem or file. You must specify the background form image TIFF file to use in the ScanTools Application definition Image Clips dialog.

See also

Clip Definition - ScanTools Plus Application

Clip Definition - ClipHelper Interface

Clip Definition - Combining ScanTools Plus Application and ClipHelper

Capture and Access Image Clips to/from the Master TIFF file

Capture Image Clips under Solution Control