Matthew Roderick - W.C.C.


Threshold Worksheet

 

I. Creating Selections Using Threshold

A. Threshold Adjustment Layer

1) Create a Threshold Adjustment Layer from Adjbtn in the Layers palette.

Original RGB
Layers


2) Adjust the Threshold Level until the appropriate separation occurs between the subject and its background. Click OK.

* This method works great to replicate natural edges such as foliage.

History Palette
Threshold


3) Grab the Magic Wand Wand and click on the area most easily selected in either white or black. Be sure that both colors are definitively separated.

* The Magic Wand easily selects due to the reduction in number of colors.

History Snapshot
Original


4) With the selection still active, Trash Trash the Threshold Layer to regain normal view of your image.

* This method can only be completed with the use of Adjustment Layers.

Layers
Fill with History


5) Double-click the Background Layer and Name accordingly.

* The Background changes from Locked to a New Layer that can be altered.

Layers
Layer


6) With the selection still active, go to Select>Menu>Inverse Selection.

Layer
Fill with History


7) Add a Layer Mask by clicking Layre Button on the Layers palette.

* White reveals and black conceals info on Layer Masks and Alpha Channels.

Layer
Final Image


8) It is now possible to add a new background such as a sky to the image.

Original RGB
Layer


9) Use a Gaussian Blur on the Layer Mask of the image to feather edges.

* This will soften and smooth the edges to enhance transition.

Gaussian
Final Image


10) Lastly, if halos around your selection edges are detected, go to Select>Modify>Contract and reduce the selection edges by a few pixels.

*Repeat these last few steps as needed for final enhancement of imagery.

Select>Modify
Contract


 

© 2007, Matthew Roderick