Image Archiving Overview
for Image Scanner Implementation Only

During scanning, image scanners running with ScanTools Plus can capture image clips of OMR grids, bar codes, grayboxes, and whole sheet sides. These image clips can be viewed during post-scan editing of the data record and, optionally, they can be archived for later access by your image archiving system. In ScanTools:

• Archiving can be performed as either a scan-time or post-scan process.
• Archiving is configured as part of your application definition process.
• Either .tif or .jpg image files can be archived. You can control image characteristics such as resolution and format during application definition.
• Flexible archive file and directory naming and index generation are available to use with your image archiving system, when using iNAME.
• You can merge scanned images with a "background form image" to restore the text, lines, and boxes that are "dropped out" to facilitate data collection during scanning. This process restores the original formatting you will need in post-scan editing and in image archive system use.

Archiving Methods

Archiving of images can be performed as either a scan-time or post-scan process:

Scan-Time Archiving

Scan-time archiving is performed automatically during scanning using the iNAME image archiving function. iNAME provides flexible file and directory naming and index generation, enabling easy access to archived images. It can be conveniently configured as part of your application definition process.

If you perform scan-time archiving, additional processes are available during post-scan processing:

• Background form images can be merged with image clips during post-scan processing. This can be configured to run automatically or manually, after scanning is complete.
• Image clips can be rotated for better viewing during post-scan processing.
• Though online editing can be used with scan-time archiving, online edit correction cannot. Correction of scanned data can be performed as a post-scan process.

For details, see iNAME Image Archive Overview, Application Definition for Scan-Time Archiving with iNAME, Scanning with iNAME Scan-Time Image Archiving, and Using iNAME Merge.

Post-Scan Archiving

Post-scan archiving is performed manually, after scanning, using the data file and corresponding clip file (.tif) generated during scanning.

• Online edit correction is compatible with post-scan archiving.
• Background form images can be merged with image clips.

For details, see Application Definition for Post-Scan Archiving and Using iNAME Merge.

Application Definition

Archiving must be configured as part of your application definition, before scanning is performed. You must decide which method of archiving you will use when you are defining the application. For additional information, see Application Definition for Scan-Time Archiving with iNAME and Application Definition for Post-Scan Archiving.

Archiving Output

Archiving produces image clip and index files:

Clip Files

Each image of a grid and/or whole sheet can generate its own image file. Scan-time archiving allows a greater choice of assigning file names. Post-scan archiving uses the six-digit document serial number assigned during scanning, plus the suffix defined in the application definition. The archive clips have a .tif file extension for Packbits RLE, CCITT G3 Fax, and CCITT G4 Fax compression. They have a .jpg file extension for JPEG compression.

Archive clips can be written in any of the supported compression formats and bit depths. If a background form .tif file is not used, the clip file is written with the same bit depth as defined in the ScanTools Plus application.

When a background form .tif file is used, the depth of the clip determines the bit depth of the final archived image, as follows:

• Bitone clip: The background form is converted to a bitone image and a single bitone image is written to disk.
• 4-bit clip (only supported with RLE compression): The background form is mapped into 16 gray tones, resulting in a 4-bit grayscale .tif file.
• 8-bit non-JPEG clip: 240 palette entries are reserved for grayscale data from the clip, and 16 palette entries are reserved for the most popular colors from the form, resulting in an 8-bit palleted color .tif file.
• JPEG clip: The clip file is a 24-bit color JPG file.

For details, see Application Settings, Image Clips, and Clip Attributes.

Index Files

The archiving process generates an index file for the archived image files. The index file is not used by ScanTools Plus, but is for the image retrieval system that will be used to store and access the image files. You specify the format you want for the index file. For post-scan archiving, you specify where the index file will reside. For iNAME scan-time archiving, the index file is written to the same location as the data file.

For details, see Archive Index Files and iNAME Configuration - Paths and Indexes Screen.

Background Form Images

During scanning of forms that are printed in "dropout" colors, much of the data "formatting" provided by the titles, captions, lines, and boxes on the form is electronically removed to facilitate data collection speed and accuracy. Since this same data formatting provides context to the information on archived form images, ScanTools software provides for optional merging of the data on the image clip with a background form image. This is a .tif file that should be supplied by the vendor who designed your form. It usually contains just the parts of the image that drop out during scanning.

Background form images are also used during application definition. They appear in the grid definition area of the Application Module to make it easier for you to locate and define grids.

For details, see Using iNAME Merge, Post-Scan Image Archiving, Horizontal Adjustment, Add/Replace Background Form Images for Sheet # dialog, and Image Clips dialog.