me start off by saying that this selection method works best in images
with high light/shadows or colour contrasts ... but it can be a very
helpful start point for making selections in all kind of pictures.|
Masking the sky in the picture I used for this tutorial seemed an apparently nightmarish task....Not anymore!!!
This is the result I got ....
.... and here are the steps I followed to get there:
1 CREATING THE MASK.
- Open the original image and duplicate the Background Layer.
on the 'Channels' Tab, pick the one with the highest contrast, (usually,
either Red or Blue...here I used the Blue Channel)and, keeping the left
mouse button pressed, drag it onto the 'Create new Channel' Tab to
on the duplicated Blue Channel, press Ctrl+L to open the Levels Dialog
and play with the sliders until you have increased the contrast until
it already looks like a mask!
- Press Ctrl+I to invert the mask.
- Use Filter > Blur > Gaussian Blur to soften the edges of your Mask.
- Keeping the Ctrl Key pressed, click on the Blue Copy Channel ... the 'marching ants' will outline your selection!
back to your Layers Palette, create a New empty Layer just under the BG
Copy, click on the 'Eye'at the left of your background Layer to
remove it, Highlight the BG Copy and click on the 'Add Layer Mask'
button at the bottom of the Layers Palette.
the empty Layer, previously created, with whatever colour or Gradient
.... or paste in that position any Background replacement of your
choice... Now, just sit back and enjoy the pleasure of having achieved
such a good result in a fraction of the time it would have taken
2 REFINING THE MASK.
this point, if you feel that, in the procedure, you have lost too
many 'small details', don't worry, you can get them back....(well
most of them anyway...)
Working on the Layer Mask, press Ctrl+L to open the Levels Dialog and, following Doug Nelson's incredible Tip, ( here), just move the middle slider to refine your mask.
refining your mask, you might not be satisfied with the strong colour
tinge, (from the original background), at the edges of your mask...
There are many ways for correcting that... for this picture, I did the following:
on the 'Create a new Fill or Adjustment Layer' at the bottom of the
Layers Palette and chose Hue/Saturation from the Menu.
- I edited the 'Blues' because this was the 'leftover' tinge in this image.
- With the 'Add to Sample' Colour Picker, I clicked on several bluish spots, trying to get a range that would cover most of them.
- I adjusted Hue, Saturation and Lightness until everything was smoothly blended with the new Background.
...The power of Photoshop never ceases to amaze me ......