Adjusting Individual Brightness Values

Use the Curves command to adjust the individual brightness values of your image. You can change any brightness value on the 0–255 scale. For example, you can change all pixels that have a brightness value of 128 to a value of 150. The Curves command gives you enormous flexibility in changing the brightness of your image.

Important: To apply this command to a selection, the image must be a 16 million (24-bit) color image (otherwise the command is applied to the entire image). In addition, adjustment layers are available for 16 million (24-bit) color or greyscale images only. To increase the color depth of an image, see Increasing the Color Depth of an Image.

To use the Curves command:

To limit the adjustment to a specific area, make a selection in the image. See Using the Selection Tools.
Do one of the following:
To modify the image pixels directly, choose Adjust > Brightness and Contrast > Curves.
To create an adjustment layer, choose Layers > New Adjustment Layer > Curves. For information on adjustment layers, see Using Adjustment Layers.

To reset the settings, in the Presets drop-down list choose Default.
In the Channel drop-down list, select a color channel to edit. Choose RGB to edit the red, green, and blue channels together. Choose Red, Green, or Blue to edit the individual color channels.
Use the points on the graph to adjust the relationship between the input levels (the brightness of the original pixels) and output levels (the brightness of corrected pixels). At the lower left of the chart, both values are zero (black). At the upper right, both values are 255 (white).
To add a point to the graph, move the cursor over the dotted red line until the cursor changes to an arrowhead and displays “+ADD,” then click the line.
To move the line, drag a point or enter values in the Input or Output edit box.
To remove a point, drag it off the graph.

Click OK.

Adjusting Individual Brightness Values

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