The
Gradient Map filter maps the grayscale range of an image to the
colors of a specified gradient fill.
Using the Gradient Map filter to simulate a sepia tone
Select
an image, layer, or area.
Do one of the following:
Choose Filter > Adjustments >
Gradient Map.
Using the Layers palette or Layer menu, create a
new Gradient Map adjustment layer, or open an existing Gradient
Map adjustment layer.
Specify the gradient fill you want to use:
To choose from a list of gradient fills,
click the triangle to the right of the gradient fill displayed in
the Gradient Map dialog box. Click to select the desired gradient
fill, and then click in a blank area of the dialog box to dismiss
the list.
To edit the gradient fill currently displayed in
the Gradient Map dialog box, click the gradient fill. Then modify
the existing gradient fill or create a new gradient fill.
By default, the shadows, midtones, and highlights
of the image are mapped respectively to the starting (left) color,
midpoint, and ending (right) color of the gradient fill.
Select neither, one, or both of the Gradient Options:
Dither adds random noise to smooth the appearance
of the gradient fill and reduce banding effects.
Reverse switches the direction of the gradient fill, reversing
the gradient map.