How to smooth or soften edges in Adobe Photoshop.

Using anti-aliasing

Anti-aliasing gently softens the opacity and color transition between edge pixels and background pixels, preserving the image’s clarity and detail. In plain English, this means that it blends the pixels along the edge of an image to make lines and borders look nice and smooth.

• Choose it:
  In the toolbar, select the Lasso, Polygonal Lasso, Magnetic Lasso, Elliptical Marquee, or Magic Wand tool.
• Check it:
  In the Options bar at the top of the screen, click the checkbox beside the Anti-aliasing option.
• Select it:
  Select the sections of the image you want to smooth.

Using feathering

Another way to smooth the edges of your image is feathering. Feathering basically softens up the edges of your selection by gently fading between the pixels on the border and the pixels in the surrounding area. This blunts any sharp edges, but it also can cause some loss of detail at the feathered edge of the selection.

• Drag it:
  Select the Marquee tool and drag your cursor around the object you want to feather.
• Select it:
  Go to Select › Modify and then choose the Feather tool.
• Feather it:
  Enter a number into the Feather Radius field. This number determines how many pixels away from the edge of your selection the Feather tool will go before it starts smoothing and blending. If you’re not sure, start between 20 and 30 and adjust as needed.

Using the Blur tool

For more experienced users, the Blur tool is an effective way to create a soft edge between two images.

• Zoom it:
  Zoom in close to your image to inspect the harsh edges you want to smooth.
• Resize it:
  Select the Blur tool from the toolbar and press ] or [ to adjust the size of the brush.
• Strengthen it:
  Use the Strength drop-down menu at the top of the screen to select how intense you want the blurring to be. The higher the percentage, the more vivid the blur.
• Blur it:
  Run the Blur tool over the edges you want to smooth.