Gradient effects reduce the transparency along one or more edges of your Image and Shape frames, allowing them to blend into the background. To add a gradient, select one or more images on your canvas, then click the Gradient & Mask tool.
Enable the gradient effect checkbox.
Choose a shape.
Adjustments may be made to gradients to define where the gradient starts within the image and how the edge appears.
Adjust Softness to affect the amount of translucency on the edge.
Adjust the Midpoint to affect how far the gradient extends into the image.
On edge gradients, adjust the Angle from where the gradient is applied.
On circular, rectangular and diamond shaped gradients, adjust the Centerpoint of the gradient on the x and y axis.
Note that gradient effects work with Shape frames as well. You can create many interesting effects to add visual interest to your pages using shapes with gradients.
Learn about Masks for other image shaping options.