About image enhancement

To improve OCR results and the quality of exported images, you can enhance your images before zoning and recognition using the SET tools.

To open the Image  Enhancement window, click the Enhance Image button in the Image toolbar, or click Tools and choose Enhance Image. You can also build Image Enhancement steps into your workflows by choosing the Enhance Images step.

Image types

We distinguish three types of image; the last two take part in image enhancement:

Original image: The image created by your scanner or contained in a file before it enters the program. It can be color, grayscale or black-and-white.

Primary image: The state of the original image after it has been loaded into OmniPage, possibly modified by automatic or manual pre-processing operations, as displayed in the Page Image panel.

OCR image: A black-and-white image derived from the primary image, optimized for good OCR results. This can be seen in the Image Enhancement window whenever a tool is selected that affects the OCR image.

The input for Image Enhancement is either the Primary or the OCR image. Because some tools affect the Primary image, others the OCR image, you must know which image you are editing.

Click the Primary/OCR Image button in the Image Enhancement window, to switch between the primary and the OCR image in the active view.

Saving is always done on the primary image – both when saving images and when graphics are embedded in recognized pages. The OCR image cannot be saved.

The Image Enhancement window

This window has two panels. When you start, the primary image is displayed in the left panel as the starting image. When you make a change, the resulting image is displayed as a preview in the right panel.

Make changes until you are satisfied, then click the Apply button in the History panel to add the change to the top of the history list. The changed image becomes the new input image on the left. Continue changing and applying as desired, then click Page Ready or Document Ready.

The History panel serves for applying or cancelling your current change. It also lets you discard changes after a given step or undo all changes made in the current enhancement session.

Use your mouse wheel to scroll page images. When the zoom tool is selected, the wheel provides a convenient way to zoom in and out on the image.

Finishing pages

To accept all changes to the page and move to the next page:

• Click Page Ready. If there are no further pages, the window is closed.

To accept all changes to the page and finish image enhancement

• Click Document Ready. Any further pages in the document will not be displayed for enhancement.

To discard all changes and return to the starting image for the page:

• Click the Discard All Changes button in the History panel.

To discard all changes to the page and move to the next page:

• Click Cancel Page. If there are no further pages, the window is closed.  

• Image enhancement steps can be saved in an image enhancement template and then can be applied to similar incoming images. 

• Select Enable Warnings from the Tools menu to get advice during your image enhancement. 

• If the program appears to freeze after using the Image Enhancement window, check that you have not unintentionally minimized the window.