DannyRaphael
02-15-2005, 12:32 PM
Image source:
* YOUR CHOICE - pick one from your own collection.
The point of all this:
* Illustrate how black and white relate to selections and masks.
* Using a Threshold adjustment layer to render a BW image.
* Creating a selection from a channel
The result:
* Does NOT have to look all that good... The point is to undertand the concepts and potential of the technique.
How to do it:
1. After opening an image (color or BW)...
Layer > New Adjustment Layer > Threshold.
Adjust the slider... Note: The result is either all black or all white. Click OK when you get something interesting.
If the Channels palette is not visible, Window > Channels.
Important:
Ctrl + click on the RGB (composite) channel.
Note: Since all the channels are exactly the same, in this case you could Ctrl + click on any one of them and the result would be the same. This is called "loading the selection."
Note: You get "marching ants" (a selection). Just so you know, the ants are marching around the white areas.
Go back to the Layers Palette.
2. Turn off (click the eyeball of) the Threshold Adjustment Layer.
Click on the Background.
Layer > New Layer > Copy via Selection (or Ctrl + J).
Note a new layer is created based on the selection.
3. In the example I duplicated the new layer to (hopefully) make the Layers Palette screen shots a little easier to understand, but this isn't necessary.
Turn off the Step 2 layer.
To the duplicate of the Step 2 layer (Step 3) I applied some Layer Style effects.
You can do that -or-
* Apply filters
* Adjustment Layers
* or anything you want to layer Step 3! :)
- - - - - - - - -
So, to summarize:
* A BW layer was created using a Threshold adjustment layer
* From the mask a selection was created by Ctrl + clicking the RGB channel
* A new layer was created based on the selection
* Effects can be applied to the selected area
- - - - - - - - -
Extra credit 1:
1. Turn on Threshold layer
2. Ctrl + click on RGB channel to load the selection
3. Back to the Layers Palette.
4. Turn off Threshold layer
5. Add an adjustment layer of your choice (except Threshold)
* Notice how the mask takes the selection into consideration?
* Experiment with the adjustment layer settings
* Close the adjustment layer dialog
* Ctrl + I to "invert" the selection
How cool is that?
- - - - - - - - -
Extra credit 2:
1. Turn on Threshold layer
2. Ctrl + click on RGB channel to load the selection
3. Select > Save Selection...
Give it a name and save it.
This allows you to preserve (save) a selection for repeated use.
Now try...
1. Select > Load Selection...
2. Chose your newly created selection from the dropdown menu.
Having saved the selection = fewer steps to reused a selection.
- - - - - -
Have fun... Ask questions if any of this doesn't add up.
~Danny~
* YOUR CHOICE - pick one from your own collection.
The point of all this:
* Illustrate how black and white relate to selections and masks.
* Using a Threshold adjustment layer to render a BW image.
* Creating a selection from a channel
The result:
* Does NOT have to look all that good... The point is to undertand the concepts and potential of the technique.
How to do it:
1. After opening an image (color or BW)...
Layer > New Adjustment Layer > Threshold.
Adjust the slider... Note: The result is either all black or all white. Click OK when you get something interesting.
If the Channels palette is not visible, Window > Channels.
Important:
Ctrl + click on the RGB (composite) channel.
Note: Since all the channels are exactly the same, in this case you could Ctrl + click on any one of them and the result would be the same. This is called "loading the selection."
Note: You get "marching ants" (a selection). Just so you know, the ants are marching around the white areas.
Go back to the Layers Palette.
2. Turn off (click the eyeball of) the Threshold Adjustment Layer.
Click on the Background.
Layer > New Layer > Copy via Selection (or Ctrl + J).
Note a new layer is created based on the selection.
3. In the example I duplicated the new layer to (hopefully) make the Layers Palette screen shots a little easier to understand, but this isn't necessary.
Turn off the Step 2 layer.
To the duplicate of the Step 2 layer (Step 3) I applied some Layer Style effects.
You can do that -or-
* Apply filters
* Adjustment Layers
* or anything you want to layer Step 3! :)
- - - - - - - - -
So, to summarize:
* A BW layer was created using a Threshold adjustment layer
* From the mask a selection was created by Ctrl + clicking the RGB channel
* A new layer was created based on the selection
* Effects can be applied to the selected area
- - - - - - - - -
Extra credit 1:
1. Turn on Threshold layer
2. Ctrl + click on RGB channel to load the selection
3. Back to the Layers Palette.
4. Turn off Threshold layer
5. Add an adjustment layer of your choice (except Threshold)
* Notice how the mask takes the selection into consideration?
* Experiment with the adjustment layer settings
* Close the adjustment layer dialog
* Ctrl + I to "invert" the selection
How cool is that?
- - - - - - - - -
Extra credit 2:
1. Turn on Threshold layer
2. Ctrl + click on RGB channel to load the selection
3. Select > Save Selection...
Give it a name and save it.
This allows you to preserve (save) a selection for repeated use.
Now try...
1. Select > Load Selection...
2. Chose your newly created selection from the dropdown menu.
Having saved the selection = fewer steps to reused a selection.
- - - - - -
Have fun... Ask questions if any of this doesn't add up.
~Danny~