Kofax vrs4 Manual Do Utilizador

Operating VRS

VRS User’s Manual

For VRS, the Contrast slider affects how the content is enhanced. VRS sees content as 

anything that has an edge. When VRS detects an edge, it is enhanced based upon the 

setting in the Contrast slider. As the Contrast value increases, the content doesn't need 

as much of an edge in order to be enhanced. Fainter content will become more visible. 

At the highest value, VRS may even enhance invisible tape or the grain of the 

document. As the Contrast value decreases, the content needs more of an edge in 

order to be enhanced. Darker content will remain, while faint content will begin to 

disappear. At the lowest value, only content like solid lines, barcodes, and logos will 

be visible.

A Gamma value is a way to manually “sync up” the image you see on the screen with 

what you are supposed to see. In other words, sometimes output devices (such as 

monitors or televisions) do not produce the same image that the input devices (such 

as a scanner) tell them to produce. In VRS, moving the gamma slider to the right will 

remove pixels from the entire image, which will create an overall appearance of 

brightening the image. Moving the slider to the left will do the opposite—adding 

pixels to make the overall image appear more dark, or dense. 

VRS handles this gamma adjustment automatically for you, so even though the 

gamma correction slider is available, you will not need it to adjust images. Gamma 

should be considered as a scanner calibration and the default value should be 

maintained.

Divide and Conquer
Every scanned image has two basic parts: the part you want and the part you do not 

want. One of the major tasks of any image processing software is to separate these 

two entities so that the desired elements are preserved. VRS excels at this task because 

VRS takes advantage of two different technologies: simple thresholding and edge 

detection. 

In simple thresholding, a grayscale image (256 levels of gray) is converted to a binary 

image (two levels: black and white). This is done by first setting a threshold level, 

which acts as a dividing line. Everything (all the pixels) above that number (level of 

gray) becomes white and everything below that number becomes black. Black pixels 

are assigned a value of 1, and white pixels are assigned a value of 0. Because the 

threshold level influences the brightness of the resulting image, we also refer to the 

threshold level as the brightness level. So in VRS, the Brightness slider on its own acts 

as a simple threshold level.