Sometimes when you scan an image, you scan more than the picture itself. For instance, very often you will notice strange lines over the scanned image or text. Such defects could be considered minor but still they are unpleasant to watch at. Or you will notice that the white background is actually dark yellowish, or that the black text is more grayish than black. If you are not a perfectionist, you can leave the scanned image or text as it is but if you don’t like things done in halves, you won’t leave the image this way. Anyway, since it is possible to make the background not “somehow white” but “perfectly white”, why settle for less?
There are several ways to correct the colors in a scanned image, the easiest of which is to use color replacement. If you are not familiar with digital image processing, color replacement might sound very complicated but actually it isn’t. It is very similar to the Find and Replace command in text processing programs – you tell the software to find all occurrences of a particular color and then to replace this color with something else.
Performing color replacement is very easy. First, you select the scanned images that need repair. Then you pick up the color that is to be corrected. If the color you need to correct appears in many places, it will be replaced in all of them, which is not always what you are looking for. For instance, imagine that the text color is the same as the grayish color of the lines on the background.
Replacing the grayish lines on the background with white will replace the grayish color of the text as well, thus making it unreadable because it will be white text on a white background. Well, this does not happen that often in practice because what looks like the same color is actually a different one but you need to know that when you replace a color in one place, it will get replaced all over the image.
After you have chosen the color to be replaced, enter the replacement color. Depending on the program you use, you might have to enter the name of the color (i.e. blue, green, lavender, etc.), or its hex value (like 000000 for black, FFFFFF for white, etc.), or its RGB value (like 0,0,0 for black, 255,255,255 for white), so you’d better check in advance the value of your preferred replacement color.
Very often you’ll discover that the color you want to replace has several shades. In this case you will have to perform the replacement command for each of the shades. You can replace all the shades with the same color or you can choose shades of the new color to make the match more precise. Put in plain English, this means that if you have 5 shades of dark red you want to replace with light red, you will need 5 shades of light red in order to produce more accurate results.
Color replacement is a very popular option and almost all image processing software has it – under one name or another. But not all programs have an option to perform color replacement on multiple files at once. One of the programs that has such an option is Image Converter Plus, so if you need to correct a color in many scanned images, you may want to download Image Converter Plus and give it a try.
Author: Ada Ivanova