Image Enhancement and Process Interactions
Image enhancements are designed to improve the appearance of documents and the accuracy of data extraction processes such as Optical Character Recognition (OCR). Which stage of processing image enhancements are used in can have a dramatic effect on the results. For example, image enhancements applied in Pre-Classification Processing will be applied to every page of every process. However, image enhancements applied in First Page Identification will be applied only for the processes used in First Page Identification, image enhancements used in Page Processing will only be applied to the selected pages, and local image enhancements will be applied only within a particular process.
Consider whether you want the enhancements saved with the documents when they are stored in Laserfiche. Permanent image enhancements are applied to the images that are stored in Laserfiche. The image enhancements applied permanently are usually those that will make the images clearer and more readable for users. Enhancements often applied permanently include Deskew, Despeckle, and Page Removal. Local image enhancements are not applied to the images stored in Laserfiche. They are applied temporarily during the Quick Fields session to improve the accuracy of a specific process. Line Removal, Form Extraction, and Smooth are examples of image enhancements that are commonly used locally.
When more than one process is used, the location of the image enhancement in relation to the processes determines whether the image enhancement is applied to each process. If the image enhancement is listed before the process in the Session Configuration Pane, it will be applied before the process is run. If it is a local image enhancement, it will be listed indented under the process it is local to (Color Removal as a local image enhancement of OmniPage Zone OCR).
Image Enhancements and Pre-Classification Processing
Image enhancements can be used in Pre-Classification Processing to optimize the documents for processes that will be used there or later in the session. Image enhancements applied in Pre-Classification Processing will be applied to all pages of all documents scanned in the session and will be permanent unless they are configured as local enhancements under another process.
Example: If you are working with documents that may have been scanned crookedly and have barcodes on them representing different values that will be used to define document classes, you could configure Deskew to improve the results of Barcode, both used in Pre-Classification Processing. You could then use the token from the barcode with Token Identification processes to identify documents as belonging to particular document classes.
You can also configure image enhancements in Pre-Classification Processing to improve the results of processes used later in the session.
Example: If all the documents to be scanned in your session have a lot of extra speckles and pixels, and you want to permanently apply Despeckle to all scanned documents no matter whether they belong to a document class, you can configure Despeckle in Pre-Classification Processing.
Image Enhancements and Identification
Image enhancements used in First Page and Last Page Identification are applied temporarily only in those stages. Changes made by image enhancements in First Page or Last Page Identification will be lost once all identification processes have been performed on a given object. To make a permanent image enhancement, apply it elsewhere in the session. Image enhancements in these two identification stages can help improve the results of processes used there.
Example: Suppose you have a single document class for which documents will be identified by an OmniPage Zone OCR process that looks for the word "INVOICE." If the documents have a lot of stray dots and pixels on them, you can apply Despeckle before OmniPage Zone OCR in First Page Identification to help improve the accuracy of the identification. The Despeckle process will be applied temporarily only within First Page Identification.
Image Enhancements and Page Processing
Image Enhancements can be applied before processes used within Page Processing to improve the results.
Example: The Optical Character Recognition (OCR) process is designed to work for black text on a white background. If the region of the documents that contains that phrase has white text on a black background, you will need to use Invert on that region to reverse the colors to black on white before using OCR.
Image Enhancements used within Page Processing are applied permanently in the order listed in the Session Configuration Pane, and only to the specific pages for which they are configured. They can also be used as local image enhancements of processes.
Image Enhancements and Post-Processing
When configured in Post-Processing, image enhancements can be applied to documents right after they are processed or upon storage in Laserfiche.
Image enhancements applied in Post-Processing will be applied permanently, and only to the specified pages.
Example: You could configure Border Padding to create a white border to the top edge of the first page of a document and Fixed Annotation to apply a stamp with your organization's logo in that added region. If you select When a document is sent to the repository under When should these processes run in the Tasks Pane, you will not see the border or stamp applied when reviewing the documents in Quick Fields, but they will be present when you view the stored documents in the Laserfiche repository.
Local Image Enhancements
A local image enhancement is applied only while another process is running, so it can improve the results of that process. Once the process has been completed, the changes made by the local image enhancement will be discarded. They are temporary and will not actually be visible after the process runs. Image enhancements can be used as local enhancements within other processes in Pre-Classification Processing, First Page Identification, Page Processing, Last Page Identification, or Post-Processing. The pages affected by the local enhancement are those specified for the associated process. Local enhancements are listed in the Session Configuration Pane indented after the process they are assigned to, but during processing they are applied before it. Multiple image enhancements applied to the same process will be applied in the order they are listed under the process.
Note: Image enhancements will always be temporary in First Page and Last Page Identification.
To add a local image enhancement
- Right-click on the process in the Session Configuration Pane, point to Insert Local Enhancement and select the enhancement you want to use.
Example: Earl wants to use OmniPage Zone OCR to extract information from a document that has been scanned in color, but wants to retain the color when the document is stored in Laserfiche. He configures Color Removal as a local enhancement within the OmniPage Zone OCR process to improve the results while retaining the color on the stored document.
Image Enhancements in Different Stages of Processing
The chart below details the properties of image enhancements in various stages of processing.
| Processing Stage | Page Range | Permanent or Temporary |
|---|---|---|
| Pre-Classification Processing | Always Every Page | Permanent |
| First Page Identification | Always Every Page | Temporary |
| Page Processing | Specified Pages | Permanent |
| Last Page Identification | Always Every Page | Temporary |
| Post-Processing | Specified Pages | Permanent |
| Local Image Enhancements | Determined by the associated process | Temporary |
