Creating a depth of field effect using the Extract Filter (Filter > Extract). You may also use the Freeform Pen Tool. Open an rgb image and duplicate the layer.

On the duplicated layer, access Filter > Extract. Check the Smart Highlighting box and use a size 13-15 brush. Trace the outline of the figure, building, etc. that you wish to stand out from the rest of the image.

Use the Paint Bucket tool at the point to paint the areas you wish to blur; everything outside the image you just highlighted.

Layer > Still on the duplicated layer, go to Filter > Blur >Gaussian Blur and use a 4.0 setting to blur everything outside the young lady. You can experiment with various filters, as in Motion Blur for different effects. In this image, we used the Blur Tool to smooth out the edges that didn't quite take to the Blur Filter and evened everything out. Enjoy!