Extract Objects - Step by Step
Step 1: Open an image that has the object you want to extract in it. Select the extract option from the filter menu and a large dialog box will pop up.
Step 2: Highlight all of the edges of the object with the highlighter tool leaving no gaps. If your brush is too small or too big, adjust the size of your brush with the brush size tool option. You want to be able to easily highlight the edges with out too much excess highlighting on the object or the background. If your object has well defined lines, you should click the smart highlighting option, this will automatically adjust your brush size and usually works great.
Step 3: Switch to the fill tool (it looks like a paint bucket) and click in the middle of your object. Your object should now be highlighted and filled with a transparent blue color. Now click the preview button, this will show you how your extracted object will look. If you’re happy with the results just click ok.
Step 4: If not try experimenting with the smoothness slider in the options side of the dialog. You will need to hit preview again after you change the slider. Also try experimenting with the edge touchup and cleanup tools found on the left.
Step 5: When you get your object looking just right click ok. Photoshop will extract your object leaving a transparent background. You can now put the object on any kind of background you like.