Color Removal

The Color Removal image refinement converts images or portions of images to black and white format. Several processes, including OmniPage Zone OCR, are designed to operate on black and white images, so you will get more accurate results if you use Color Removal before using data extraction processes, or before applying other image refinements such as Invert.

The stage of processing where you use Color Removal depends on your overall goals. For example, when configured in Pre-Classification Processing, Color Removal can optimize text for other processes, such as OmniPage Zone OCR, used in Identification or Page Processing. Configured in Page Processing, it will optimize text for other processes used after it within Page Processing. Used as a local image enhancement, it will optimize the text during processing, but will allow you to keep the image in its original color format for storage.

Note: Color Removal was previously known as Dynamic Thresholding.

To use Color Removal

1. In the Session Configuration Pane, select the stage of processing where you want to use Color Removal.
2. In the Tasks Pane, select Color Removal. In the bottom right of the Tasks Pane, you can select Wizard to display more information about each property or Skip Wizard to display the properties all at once without additional information.
3. Page Range: When configuring an image enhancement in Page Processing or Storage Processing, you will be prompted to specify a page range. In other stages, default settings will automatically be applied.

   Tip: A black and white image takes up less disk space than color or grayscale images. A reason to convert the entire page to black and white and store it that way in Laserfiche would be to maximize disk space.

4. Region Selection: Specify the region that will be converted to black and white. You can convert the entire page or a selected region. To define a region, select Region and either drag and resize the zone on the Display Pane or specify coordinates in the Tasks Pane.  

   Tip: You can convert regions containing text to black and white while retaining illustrations on the page in their original color format in order to optimize the text regions for processing and storage without compromising the quality of your illustrations.

5. Shaded Backgrounds: To optimize processing for images with shaded, colored, or non-uniform backgrounds, select Compensate for Shaded Backgrounds. If you do choose this option, select or specify a level of sensitivity to determine how carefully the background color of the image will be calculated and adjusted. The higher the number, the greater the sensitivity.
6. Image Contrast: The Image Contrast setting determines how dramatically the image contrast will be modified. Specify a value or use the slider to adjust the contrast for processed images.
7. Optional: To preview how this enhancement will affect scanned images and OCRed or extracted text, test processes. For the best results, add a custom sample image before testing. Adjust and test until you are satisfied with the results.