Brightness, contrast, and color balance palette

 

 

An introduction to color

 

 

Click the brightness, contrast, color-balance button in the

 

 

In photography, red, green, and blue are the

 

RED

 

 

primary colors. The secondary colors, cyan,

 

image-correction tab to display the palette.

 

 

 

 

 

 

magenta, and yellow, are made from combin-

 

 

 

 

 

 

 

Drag the brightness, contrast, or color sliders, or enter specific

 

 

ing the primary colors: cyan = blue + green,

MAGENTA

YELLOW

 

 

magenta = blue + red, and yellow = red +

 

 

values in the corresponding text box to make corrections.

 

 

 

 

 

 

green. The primary and secondary colors are

 

 

Dragging each slider to the right or inputting a positive number

 

 

 

 

 

 

grouped in complementary pairs: red and

 

 

in the text box increases the brightness, contrast, and color.

 

 

 

 

 

 

cyan, green and magenta, and blue and yel-

 

 

 

 

 

 

 

Changes are reflected in the displayed image and in the graph

 

 

low.

BLUE

GREEN

 

 

 

at the top of the palette. The horizontal axis of the chart indi-

 

 

Knowing the complementary colors is very

 

 

cates the original image values and the vertical axis the new

 

 

 

 

 

 

important in color balancing. If the image has

 

CYAN

values.

 

 

 

 

 

a specific color cast, either subtracting the

 

 

 

 

 

 

Clicking the auto-setting button corrects the brightness and

 

 

color or adding its complementary color creates a natural looking image. For example, if the

 

 

image is too red, decrease the amount of red; if it is too yellow, increase the amount of blue.

contrast automatically without affecting the color balance. Click

 

 

 

 

 

 

 

the reset button to cancel all changes. Click the close button to

 

 

Adding or subtracting equal parts of red, green, and blue has no affect on the color balance.

close the palette and apply any changes.

 

 

 

 

However, it can change the overall image brightness and contrast. Usually, no more than two

 

 

 

 

 

 

color channels are needed to color balance an image.

 

 

 

 

 

 

 

 

Close button

Color balancing is a skill that develops with practice. While the human eye is extremely sensitive

 

 

 

 

 

 

in making comparative judgements, it is a poor tool when making absolute measurements of

 

 

 

color. Initially, it can be very difficult to distinguish between blue and cyan, and red and magenta.

Is this picture too light? Adjusting brightness and contrast can

 

 

However, adjusting the wrong color channel never improves an image; subtracting blue from an

 

 

image that is too cyan gives a green cast to the image.

 

be more difficult than it looks. The image on the right looks too bright, especially the mountains in the background.

Undoing and redoing image corrections

Simply making everything darker with the brightness controls creates a muddy image - the snow and sky are a dull gray and there are no strong blacks.

By adding contrast to the image, the snow is brightened while the darker trees are accentuated. The extra contrast also gives the image the appearance of being sharper as well as revealing fine details.

The undo, redo, and reset-all buttons only affect tools used in the image-correction tab.

Click the undo button to cancel the last image correction applied to the image. The number of image corrections that can be undone depends on the computer memory capacity.

Click the redo button to reapply the last image correction canceled with the undo button.

Click the reset-all button to cancel all image corrections applied in the image-correction tab.

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Basic image processing

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