Digital Light & Color

Forgive me for asking what probably is so simple, but here goes anyway:
1. How do I change the background of a shot to a single color ... for instance, if I do a portrait, how do I change the background to solid black ... or gray ... etc. My guess is that I have to do a mask of the subject first (right?) ... or is there another way???
2. Assuming I have to do a mask, how do I avoid the sharp edging that occurs with the mask?

Thanx for your help on what probably is digital photography 101 stuff ...

Tom

Tom,

First make an image of a solid background color. Select your foreground image and then use File/New to create a new image. The dialog allows you to choose any color for the image. Then make a mask in the foreground image isolating its foreground from the background. Feather the mask to avoid sharp outlines. Finally use Composite to combine the images. You will find detailed examples in the Picture Window User's Guide, Chapter 11, Combining Images.

Kiril

Hi Tom, you may also want to watch a brief video tutorial I've posted on this subject:

http://www.picturetheweb.com/ptw/video/ ... ks_01.html

...actually I meant to send you to this link:

http://www.picturetheweb.com/ptw/video/ ... sks02.html

... but they both illustrate some helpful tips about making selections.

Mark,

Thanks for providing the video links. I watched them both. Clear, informative and I learned a couple of things!

Mike.

Thank you, MarkT. I learned three things about effective masking of a sky over a mountainous horizon, a face out of an image, etc. that I did not notice in the PWP manual. One, for this task the size of feathering relates to the pixel dimensions of the image. Two, apply feathering several times in succession for a more gradual boundary between mask and unmasked areas. Three, you chose feather over blur for this task.

Great tutorials, Mark ... I'm now going to attempt to apply your lessons to my 'project' ...

Both of the tutorials you sent were very informative ... do you have some others available for review as well ???

Tom

Additional Solid Color Background considerations might include:
(1) As mutual transference [reflected light] remains with a visual object extracted from its original background, it may be advantageous to choose a solid background color whose Hue, Saturation, and Value will be in a +/- 20% range of the average original background tone/colors... at least in the near vicinity of the extracted visual object;
(2) As large image areas of solid color do not normally occur naturally, it may be advantageous to add a 2 to 4% ‘noise’ of choice and/or a slight ‘texture’;
(3) As backgrounds are not uniformly lighted, it may be advantageous to provide a 20% light to dark Value gradient appearing to emanate from the apparent main light source of the extracted visual object; and
(4) To simulate a 3 dimensional effect, it may be advantageous to add a barely discernable ‘drop shadow’ around the extracted visual object.

Alternates to Solid Color Backgrounds might include:
(1) Crop for composition and to eliminate extraneous background elements,… …then strongly darken or strongly lighten a vignette around the extracted object using an appropriate blending gradient so as to avoid objectionable halo/aura transitions; and
(2) Consider retaining the original background if it provides main visual object(s) context(s) or texture(s) but blurred, low contrasted, and de-saturated with the main visual object(s) at preference tone/color/sharpness and possibly secondary visual objects at slightly less than preference tone/color/sharpness…

Just some thoughts…