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Adjust a specific color in the tonal range with Curves



The Curves feature provides more precise control over the tonal range than the Levels feature. The Curves feature lets you adjust any color along the tonal range, without affecting other colors.

The grid in the Curves dialog box illustrates two brightness values:

The horizontal axis
Represents the original brightness of the pixels, shown in the Input box

The vertical axis
Represents the new brightness values, shown in the Output box

When you first open the Curves dialog box, the diagonal line indicates that no changes have been made, so the input and output values are the same for all pixels.

  1. Select the image.

  2. Do one of the following to open the Curves dialog box:

    • In the Property inspector, click the Plus (+) button beside the Filters label, and then select Adjust Color > Curves from the Filters pop-up menu.

      Note: If the Property inspector is partially minimized, click the Add Filters button instead of the Plus button.

    • Select Filters > Adjust Color > Curves.

      Curves dialog box

  3. In the Channel pop-up menu, select whether to apply changes to individual color channels or to all colors.

  4. Click a point on the grid's diagonal line and drag it to a new position to adjust the curve.

    • Each point on the curve has its own Input and Output values. When you drag a point, the Input and Output values update.

    • The curve displays brightness values of 0 to 255, with 0 representing the shadows.

      Curve after dragging a point to adjust

      To adjust highlights, midtones, and shadows automatically, click the Auto button in the Curves dialog box.

Delete a point along the curve

 Drag the point off the grid.

Note: You cannot delete the end points of the curve.

Adjust the tonal balance manually

  1. Open the Levels or Curves dialog box, and select a color channel from the Channel pop-up menu.

  2. Select the appropriate eyedropper to reset the tonal values in the image:

    • Click the lightest pixel in the image with the Highlight eyedropper  to reset the highlight value.

    • Click a pixel of neutral color in the image with the Midtone eyedropper to reset the midtone value.

    • Click the darkest pixel in the image with the Shadow eyedropper to reset the shadow value.

  3. Click OK.