Select the refine edge brush tool on the left side of the workspace.
Surface blur photoshop to clean up floor.
Stamp a new merged layer shift cmd ctrl opt alt e and select the gaussian blur radius according to how much you want to smooth out the surrounding background.
A very basic and quick overview of using surface blur and smart sharpen to clean up the quality of gifs for tumblr.
Photoshop is a great program to use for just about everything.
I didn t do it in my example.
The extensive selections of tools in photoshop can be daunting for novice users.
Then drag over the edge of the subject to clean up the mask edge.
Just stick a new floor.
Then select a radius of 15 30 pixels depending on the amount of dirt and grime on the background.
Don t forget to add the same noise to this layer using the steps as before.
That being said go to filters blur surface blur and when the window pops up change the radius to somewhere around 9 and the threshold to 27.
Which as you can guess dodge and burn frequency separation and other techniques used by high.
To further fine tune the image you can have photoshop compute and consider blur traces for multiple regions.
Click filter noise median.
Automatic camera shake reduction takes into account the blur trace for just the default region of the image that photoshop has determined as most suitable for blur estimation.
Being used to cleaning skin with dodge and burn for beauty i tend to do the same with weddings.
As suggested in the comments you got find a similar floor and add it with the right perspective and shadow in photoshop.
You ll need to use the wall s angle to align the planks of the floor.
Select the brush tool on the left check that the plus icon is enabled at the top of the workspace and paint over a hidden area you want to bring into view.
There are a zillion buttons to push and.
You ll probably need to apply some shadows in the corners to make it more realistic.