When scanning and opening documents, Readiris applies several Preprocessing options.
To access these options:
On the Readiris menu, click Preferences.
Click the Preprocessing tab.
The options you set here are applied as default to all the documents you'll open or scan. Note that changing these options does not affect the images that are already open in Readiris.
Note that you can also access these options via the Settings menu.
This option is activated by default. It renders grayscale and color images more homogeneous by smoothening out differences in intensity. As a result, a stronger contrast is created between the foreground (text) and background (artwork). Sometimes smoothening is the only way to separate text from a colored background.
This option removes unwanted dither (noise) from black-and-white images.
Select the option Process as 300 dpi when you are processing images of an incorrect or unknown resolution. The images will be processed as if they had a 300 dpi resolution.
To remove vertical lines:
Select Remove vertical lines.
Enter values for the 3 parameters:
Minimum length: minimum length (in pixels) of the lines to remove.
Maximum thickness: maximum thickness (in pixels)of the lines to remove.
Maximum gap: maximum line gap (in pixels) to close, in case of broken, interrupted lines.
To remove horizontal lines:
Select Remove horizontal lines.
The same parameters are available.
Note that lines are only removed to improve the recognition. They are not removed from the output files.
Sometimes documents contain a lot of "noise" - little black spots that occur when scanning low-quality documents or using bad scanner settings.
To remove these little black spots, use the Despeckle slider. The more you move it to the right, the larger the spots that will be removed.
When you are done, close the Preferences window. The settings are saved automatically.