There are many ways to extract an object out of an image and Photoshop Extract filter is one of them. It works best on images with lots of contrast between the object and background or images with hair or tree branches.

1- Duplicate your layer using Ctrl+J or by dragging the layer to new layer icon in layer palette.

2- Now go to Filter>Extract or press ALT+Ctrl+X

3- Now select  Edge Highlighter tool (B) as shown below and click on zoom button to zoom into the object you want to extract.

4- Now draw an outline around the edges of the object you want to extract. Depending on your image you may want to adjust the brush size. Hold down CTRL to use Smart Highlighting.

5- Once you're done highlighting, select the fill tool and click inside your outline.

6- Click on Preview button to see a preview of your cut-out, If you're not satisfied with the result use use Edge Touchup tool to redraw your edges and then click ok.

7-  You will be back to main Photoshop screen with your extracted image. If you are still not satisfied with your result click on Add mask in your layers panel and select black as your foreground color. Now use brush tool and paint on areas you want to cut-out.

8- Below is our final image.