Changing an Image’s Brightness, Contrast, and Other Settings
You can change the brightness, contrast, and other settings of images to improve their
quality or to create interesting effects. Adjustments you make don’t affect the original
image; they affect only the image’s appearance in Numbers.
To adjust an image:
1
Select the image.
2
Choose View > Show Adjust Image.
Adjust the contrast of light
and dark tones.
Change the color intensity.
Introduce more warmth
or coolness.
Change the amount of red
or green tones.
Sharpen or soften
the focus.
Adjust shadows and highlights.
Understand the relationship
between shadows and highlights.
Change the levels of dark
and light tones.
Restore original settings.
Adjust the lightness.
Enhance colors
automatically.
3
Use the controls to make adjustments.
Brightness: Changes the amount of white in the image. Dragging to the right
increases the white in the image, making it appear brighter.
Contrast: Changes the difference between the light and dark areas of the image. If you
increase contrast, the light parts get lighter and the darks get darker. If you decrease
contrast, the difference between light and dark decreases. Dragging to the right makes
the edges between light and dark areas more stark and can make a photo appear
more like an illustration.
Saturation: Changes the richness of color in the image. Dragging to the right makes
the colors richer or more vibrant.
Temperature: Changes the warmth or coolness of the image by adjusting the amount
of warm tones (red) or cold tones (blue).
Tint: Changes the overall color cast of the image by adjusting the amount of red or
green tones.
Sharpness: Sharpens or softens (blurs) the focus of the image.
Exposure: Changes the overall lightness or darkness of the entire image. When you
adjust exposure, every part of the image gets lighter or darker. Increasing the exposure
of an image can also reduce its color.
Histogram and Levels: Describes the total color information in the image, from the
darkest shadow on the left, to the brightest highlight on the right. The heights of the
peaks tell you how much color information falls in a given range.
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Chapter 9
Working with Shapes, Graphics, and Other Objects
Chapter 9
Working with Shapes, Graphics, and Other Objects
201
To set the dark level, drag the left slider toward the middle. Dragging the slider to
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the right narrows the range of color and can bring more clarity to the shadows. The
position of the slider determines how much information is in the darkest part of the
image; any information to the left of the slider is omitted from the image. You may
want to drag the slider just to the point that the histogram line shows a noticeable
bump, signifying that detail is available.
To set the light level, drag the right slider toward the middle. Dragging the slider to
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the left narrows the range of color and can bring more clarity to the highlights. The
position of the slider determines how much information is in the lightest part of the
image; any information to the right of the slider is omitted from the image. You may
want to drag the slider just to the point that the histogram line shows a noticeable
bump, signifying that detail is available.
Enhance: Automatically adjusts the image by spreading the red, green, and blue tones
evenly across the histogram.
4
To restore the original settings, click Reset Image.
To save any changes you made, save the document. The settings at the time you save
the document are visible anytime you open the Adjust Image window.