Wednesday, 2 October 2013

Tutorial 5: Refining edges with selection

I would like to place a portrait of my Sister onto a background, but I don't want to simply cut and paste, I want to blend my subject onto the background, and this is where ‘refine edge’ helps to create that effect.



First I start by opening both images in Photoshop, and as the tropical image is going to be the background of the final image, I will need to bring the portrait across to the background document as a new layer. Using the ‘Rectangular Marquee Tool’ found along the toolbar (or press ‘L’), I trace around the border of the portrait image. A moving outline appears around the border meaning the image has been selected.
Next I then select the ‘Move’ tool along the toolbar (or press ‘V’) and I drag the selection to the tropical image document.
My portrait is then added as a new layer atop the background image. I then move the image to where I wish to place the subject within the background.

As I only want my sister in the tropical background and not the grey backdrop behind her, I need to isolate her from the backdrop using one of the selection tools.
To create an accurate trace of the subject without the worry of unsteady tracing, the polygon lasso tool, found in the toolbar (or press ‘L’) allows you to trace from linking lines as the outline. To create a more accurate effect to bring out edge definition in the end result, its best to keep the outline within the subject’s inner edge, so that the edge can be recovered.

Once my subject is outlined, including the area at the edge the image, a selection border appears to show the isolated object. Next I select ‘Refine Edge…’ found along the Polygon lasso toolbar options at the top, this then opens up a window.
Under ‘View mode’ there is a small image of the selection and by clicking on the small image, I can view the image in different ways, as it gives different options to show the selection. I chose the ‘on layers’ option so I can view the subject against the background.

The image currently looks like a cutout, as there are only straight edges viewed of the subject. Under edge detection in the window, the ‘Radius’ dial is used to recover more detail in the outer radius of the selection.  As I drag the dial slightly to the right, this then extends the edge further outward from the outline.

The refine edge effect in Photoshop makes calculations based on the pixel colour values defined along the outline and Photoshop attempts to bring out edge detail in the subject without including the original backdrop. As the radius value is only set as an over all radius value, there is an option that allows you to manually extend the radius, by side clicking on the paintbrush image beside ‘edge detection’ and select ‘Refine radius tool’ give you a paint brush where you can trace the outer edge by dragging the paintbrush. Once you release the clicker, Photoshop then calculates the refine edge.

Once I am happy with as much detail on the edges, my next step is to fix the edge, as it isn’t entirely natural. Under ‘adjust edge’ there are options the manipulate the blend of the edge; ‘Smooth’ adds a blur effect to the edge, ‘feather’ well creates a feathered edge, “contrast’ creates a stronger edge which in this case is not entirely effective. For my image, I used ‘shift edge’ which softly blends the image, with value set to 20%, created a nice, soft effect.
In the case of most images that need to be isolated from the original backdrop, even though there is refined edge, there are still remnants of the original background colour. By selecting the box ‘Decontaminate Colors’ and setting the amount that I want, in this case I have set the amount to 70%, diminishes the colour.

Before clicking ‘OK’ I make sure the Output is set to ‘New layer with layer mask,’ so that when I click OK a new layer is made from the selection and refine edge and a layer mask is also set beside the layer. The original layer is automatically hidden, with the eye icon unselected’, as the layer is not needed anymore.

The mask layer allows you to make further adjustments by using the paintbrush found along the toolbar (or press ‘B’), whether the paintbrush is set to white or black allows you to reveal or hide more of the edge.

As I am happy with my end result, I don’t make any more alterations with the layer mask. The very last adjustment I make to my image is using the blur tool found along the toolbar, to take away detail in the rock beside my subject, as it is in focus. By slightly blurring the rock, it separates the subject from the background and creates a sense of depth in the image.
  
And my end result:

  

Sources:
Tutorial: http://www.photoshopessentials.com/photo-editing/selecting-hair/ All Content © 2013 . Not to be duplicated or redistributed without permission. Photoshop is a trademark of Adobe Systems Inc.




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