Thursday, April 24, 2008


Todays episode was going to be a simple cut-out. I started with a simple shape from an old portfolio picture of mine. A change in background would work well.
I opened the picture in Adobe Photoshop and tried various ways of selecting either the background or the head but neither worked. Of course I could have gone right tound it with the lasso tool - but I find when you get to a corner the lasso generally lassoos itself through a bit you didnt want to go through. The other alternative is the pen tool to make a path that can be converted to a selection. Well- you folk out there don't learn from doing it the easy way so here is how I finally got to cut it out. The first problem I had was that the image was grainy and the edge was not very well defined. To make the edge clearer I chose to use a channel. I opened the channels folder and selected first the blue channel`nd made a copy of it. This wasn't quite right so I made a copy of the red channel - this was good enough. (Unhappily when I set photoshop up I elected to show channels in colour so this is a good reason not to as you can see straight away which channel is going to give the best contrast).
The next step is to enhance the edge of the subject (it isn't really necessary here as the edge is quite clear - but you might need to do this sometime). This takes several steps.
  1. click: Image/Adjustments/Equalise
  2. The next step is click: Filter/Other/HighPass - and choose a radius that gives the best definition

  3. Next: Image/Adjustments/Levels - to give a high contrast
  4. Next you can start erazing the background roughly, not to close and eraze it to white (ie background color white)
  5. For the next step you need to clean up to the subject - I do this at fairly high magnification to see what is happening. For the forehead I used the Lasso tool and for the nose, mouth and chin I used the Pen tool to make a path which I converted to a selection. Just click on your Delete button on your keyboard to clear a selection.
  6. When I had converted the path to a selection I addeed a layer and filled my selection with white. (When you convert a path to a selection you get the opportunity to "feather" curves which I did at 1 pixel). The next thing to do was to select the white backround I did this with the Wand tool. I realised that it was going to crop into the head so I made yet another layer and filled the background with grey (it could have any colour just that I needed to see what was going on.
  7. Finally I re-selected the layer with the mouth etc. and selecting the background inverted my selection then in the top layer with the rest of the background I erazed the area where the main background was overlapping. This was easy to do as I just rubbed out up to the selection dots. To give this result:

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