2023

User Guide | 411
Color Balance - To remove unwanted color casts or correct oversaturated or ●
undersaturated colors. This effect changes the overall mixture of colors in a
picture for generalized color correction.
Hue/Saturation - To adjust the overall color intensity and light in a washed-●
out or muted picture, but is generally used as a special effect. The picture’s
current hue (color cast), saturation (intensity), and lightness (degree of white
light) are expressed as zeros by default.
Selective Color - To increase or decrease the amount of process color in ●
each of the primary colors in a picture. For example, if an apple is too purple,
you can take cyan out of the areas that affect red.
Gamma Correction - To adjust the white point. Adjusting the white point ●
controls the brightness of the picture’s display on screen. To use the Gamma
Correction dialog box, adjust the midtones by entering a new value in the
Gamma field or by dragging the slider. A higher value produces a darker
picture, overall.
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Although modifying gamma gives you some control over picture display,
differences between Windows and Mac OS may still cause issues. Windows
uses a higher gamma value (2.2) for display than Mac OS (1.8), so the same
picture will look darker on Windows.
Desaturate - To convert a color picture to a black-and-white picture while ●
leaving the color mode and lightness value of each pixel unchanged. For
example, it assigns equal red, green, and blue values to each pixel in an RGB
picture to make the picture appear grayscale
Invert - To invert the gray values of each channel in a picture. This effect is ●
recommended for 1-bit, grayscale, and RGB pictures. Because CMYK
pictures contain a black channel, this effect is not recommended for CMYK
pictures. The inversion of the black channel usually results in images that
are mostly black or mostly white.
Threshold - To convert color pictures to black and white, without using gray. ●
Enter a value in the Threshold field or drag the slider; all pixels lighter than
the threshold value are converted to white and darker pixels are converted to
black.
Posterize - To modify the tonal levels for each channel in a picture to ●
produce special effects. To use the Posterize dialog box, enter a new value in
the Levels field or drag the slider. For example, choosing five tonal levels in
an RGB image results in 15 colors (five for each of the three primary colors)..