About Image Brightness and Color Adjustment Methods
You can adjust the brightness, contrast, color, etc. of images with the row of buttons under [Image Settings] in the [Advanced Mode] sheet.
The items that can be adjusted are explained below.
Brightness/Contrast [
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]Adjusts the brightness and contrast (difference between light parts and dark parts) of images. If you weaken the contrast, the difference between the dark and light parts is reduced and a soft image is produced. Conversely, if you strengthen it, the difference between the dark and light parts increases and a sharper image is produced.
Histogram [
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]The distribution of brightness in the image is displayed as a graph. In the image displayed in the preview, if you select the part you want to be lightest or darkest, with that as the standard, the software can automatically adjust the balance between the light and dark parts of the entire image. Similarly, you can also adjust the balance with the brightness of halftones as the standard.
Also, with parts that you want expressed as uncolored (color like black, gray, and white that have no hue) as a standard, you can readjust color tones in other parts of the image. For example, if there is a blueness in the snowy parts of a photographic image, selecting those parts in order to express them in their true whiteness adjusts the entire image toward colors approaching nature, with the blue removed.
Tone Curve Settings [
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]Changes before and after adjustment of the brightness and contrast of an image are displayed as curves.
You can adjust by selecting a registered tone curve.
If you overexpose, the entire image becomes lighter, and if you underexpose, the entire image becomes darker. If you increase the contrast, the difference between light and dark parts is emphasized, and if you convert the image to negative, the light and dark parts are inverted.
Threshold [
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]Adjusts the threshold of black and white images. Threshold is the value that becomes the border distinguishing black and white, wherein colors of densities below a given standard are distinguished as white, and densities above that standard are distinguished as black.
You can use this function to sharpen text, or to prevent bleedthrough (a phenomenon where text or images on the back of a page are scanned) when scanning newspapers etc.