Images are edited to correct possible image distortions primarily when processing photos of documents (including from mobile devices) and document scans with complex background that impedes recognition and data extraction (for example, certificates, passports, etc.). This stage allows you to improve recognition results for low-quality images.
Images are processed by means of a special panel in the main window of the program. To open the image enhancement panel, take one of the steps below:
- Click on the image editing tool bar
- Select Enhance Image in the Page main menu
- Select Enhance Image in the context menu of a page
Image enhancement panel
Image enhancement panel allows an Operator to create a sequence of editing actions that will be applied to pages one by one from top to bottom.
To edit an image, proceed as follows:
- In the batch window, select an image to be processed. It will open in an image window.
- Select image editing tools with an on / off toggle to the right from each action on the image enhancement panel.
Image editing tools
- Autoсrop - automatically searches for page boundaries on an image, crops the area that contains data for extraction, corrects skews and distortions. There are three available modes: Generic, Photo, and Scan
- Remove ISO Noise - removes noise from an image
- Remove Motion Blur - removes blur that occurs when moving a document or a camera/scanner
- Photo Correction:
- Whiten Background - whitens the background of an image
- Equalize Brightness - equalizes brightness of an image
- Remove Color Marks - removes all color marks from an image
- Remove marks of specified colors only - removes marks only of the specified color
Note. If this option is not marked, all color marks except gray scale marks will be deleted from an image. For example, if you need to delete blue stamps and leave green headings, mark this option and select a color.
- Deskew:
- Use black separators to correct skew - allows you to correct image skew using black separators
- Use black squares to correct skew - allows you to correct image skew using black squares
Configuring background color at the deskewing stage
You can change the color of the background that appears beyond the edges of the image when you start deskewing it. To do this, set the value of the DeskewColor registry subkey of the [HKEY_CURRENT_USER\Software\ABBYY\ScanStationRS\5.0\Shell\PageView] subkey to the following value: redComp + greenComp*256 + blueComp*256*256. If the value of the subkey is left unspecified or its value is set to 4294967295, the background color will be determined automatically.
- Remove Geometrical Distortions - removes geometrical distortions
Note. The image deskewing functionality is embedded into the Autoсrop tool (see above). Therefore, if you have already selected the Autoсrop tool, this option may be left disabled.
- Remove Scanner Shadow - removes scanner shadow from an image
- Brightness & Contrast - allows you to configure brightness and contrast of an image
- Convert to B\W - converts color and gray images into black and white
- Despeckle - removes small extra elements from an image. This option is applicable only to black and white images.
Important! If source text in images is very light or it includes thin type and if the size of elements to be despeckled is set by a user, it is necessary to make sure that significant elements like punctuation marks and thin letter elements are not deleted when the Despeckle function is enabled.
Note. After any editing action you can always restore the original image.
- Set the sequence of actions. The sequence may be important in certain cases, for example, when you need to configure brightness and contrast of an image before deleting color elements.
Some actions have a fixed position, other can be repositioned. To reposition an action, take one of the following steps:
- Hover you mouse pointer over the vertical ellipsis to the left from the name of the action, click and hold the left mouse button and move the action to a different place
- Select an action from the list, click and hold Shift and move the action by means of up / down buttons on the keyboard
To apply the changes, click Apply. To discard the changes, click Reset.
If you want editing changes to apply automatically on an image when selecting an action, enable the Auto Apply option. Bear in mind that auto-apply of changes takes some time.