Replacing Backgrounds Tutorial #1

[TTQ B4U]

I get a lot of questions on what is the best way to replace backgrounds. The answer remains that there is no one single best way as the methods vary with the image. In many cases however, several ways can be used to get to the same results which is an effective and detailed layer mask.

 

A layer mask is much like what you would imagine in say painting a room. It's like masking off the areas you don't want to paint or in this case, change leaving the unmasked area for editing. A layer mask is created by either by drawing white on a black background or black on white background high contrast image. The best thing to do is practice and master each method and learn which applies when.

 

Here's one example I thought I would share. Perhaps over time I'll elaborate on the others too.

 

Photoshop CS5:

 

The Key is to have the following layers:

 

1. Layer Mask (Where you deleted the blue) thus allowing the pink to show through
   
2. New Background (Pink)
   
3. Background (original image)
   

Original Image:

 

 

http://www.pbase.com/timothylauro/image/145466273/original.jpg

 

 

 

Step 1:

Open the image in Photoshop and use the Calculations command (Red and inverted Blue channels with Color Dodge blend mode) to create an alpha channel.

 

http://www.pbase.com/timothylauro/image/145495127/original.jpg

 

Step 2:

 

Load the alpha channel as a selection then used the Refine Edge function to fine tune the selection, especially address the blue color bleed and edge contamination. Saved as a New Layer with mask which automatically knocked out the old blue background.

 

 

http://www.pbase.com/timothylauro/image/145494712/original.jpg

 

Note the amount of detail retained fabric fibers retained by this method. That's a 200% enlargement shown.

 

I know I kept it brief and went quick but feel free to post questions or PM me if you're stuck.