Image -> Adjust -> Brightness/Contrast...
This dialog allows you to change the contrast and brightness of an image. This is a very simple and fast adjustment of the tonal range of the whole image.
As you move the sliders, you can immediately see the results on the original image. The Tone Curve shows you the Input/Output relations as well. On the X axis are the values of original image, the Y axis displays the adjusted values of the result image.
Contrast is the difference between light and dark tones. As you move the Contrast slider up, you will see that the tone curve angle changes and becomes more vertical. This means that more values around the midtones from the original image are mapped into a larger tonal scale (stretched around the gray midtones) on output.
Brightness moves the tonal curve up and down, thus shifting the input image more toward a bright or dark tone.
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 Adjust Contrast |
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