|
This lesson demonstrates how to extract backgrounds utilising the Magnetic Lasso
Tool. To work along exactly, you are welcome to download my crystal image Here. Unzip the file and open it onto Photoshop’s workspace.
The Magnetic Lasso tool
The success of the Magnetic Lasso tool largely depends on the contrast between subject (crystal) and its background. When applying the Magnetic Lasso tool, the lasso line adheres to the edges of defined areas in the image (IE the crystal’s edges).
Learn how Channels can make applying the Magnetic Lasso Tool easier, Here.
Undo and Navigation Steps
Two ways of undoing steps are from the top menu, Edit then Step Backwards. Alternatively, click a previous snapshot in the History Palette.
Navigate (zoom in and pan) your image using the Navigator Palette,
or the Zoom Tool. 
Activate The Hand Tool by tapping the Spacebar, keeping the Spacebar pressed, pan your image in the usual way. 
1/
Open your start image onto Photoshop’s workspace.
2/
Then unlock the Background layer by double-left-clicking it, and clicking OK from the subsequent New Layer dialogue box. Your layer will then change to Layer 0.
3/
From the left-side toolbar, activate the Magnetic Lasso Tool.
And set the following attributes into the Options bar.
Note
I am using Photoshop’s default settings and they work with the crystal image, however, experiment with the settings (above) and find what work best for your image. You may need to experiment with the Edge Contrast setting. Feather lets you decide the feather (fade) between the object you are isolating, and its background. Frequency decides how often the anchor points are deposited.
To remove the marquee at any time, from the top menu choose Select then choose Deselect.
Tip
To zoom into your image, from the top menu choose View then choose
Zoom in.
Tip - retracing your steps
Whilst applying lasso line and before the marquee is applied, to go back one step, press (either) the Delete or the Backspace key of your keyboard - press your chosen key for however many steps you want to go back - this is for Windows XP users, I am currently unfamiliar with Mac’s.
4/
Now, somewhere on the edge of the crystal, left-click to begin the magnetic lasso, I am starting as illustrated below.
 |
Move your mouse cursor a few millimetres upwards, tracing the crystal’s contour, and the first anchor point will be automatically applied. There is no need to left-click at this point.
 
Now, slowly and carefully trace the contour of the crystal with your mouse (no left-clicking is necessary) - and anchor points, little white - square - boxes, will be deposited automatically. Alternatively, left-click to apply anchor points where you want them to
be. Be prepared to practise this technique a little. Your aim is to surround the crystal (or your own object) with a lasso line. Take your time, and keep an eye on the contour during the application. If you make a mistake, retrace your steps as mentioned in my Tips above - or start again. To abandon the lasso completely, double left-click.
 |
Tip
The slower you work, the more accurate the lasso line application will be, therefore, for a good result, take your time.
Tip
When the lasso has changed to a marquee; If part of the crystal has been omitted, as demonstrated here. 
From the Magnetic Lasso options palette, ensure the Add to selection tab is active.
And apply the lasso around the missed area (below middle). Left-click, and the lasso will follow the crystal’s contour, (below right).
 
Additionally, if the lasso transcends the crystal, as demonstrated below.
Change the tab to Subtract from selection. 
And draw a lasso around the crystal’s edges, (below left). Now, left-click, and the marquee should follow the contours of the crystal, (below right).
 
5/
When you have fully surrounded your object with a lasso, and mopped away errors, pass your cursor over the exact point where you began.
And left click. Your object will be surrounded by a selection marquee, as shown below. Remember, this technique may take a little practise.
From the top menu, choose Select then choose Inverse.
6/
Now, press the Delete key of your keyboard, and the background will be removed, leaving the following transparent (chessboard) effect.
Tip: If you find the edges are slightly ragged, activate the Blur Tool from the toolbar, set the Opacity to around 5, and gently blur (soften) the edges.
Inverting the selection ensures the crystal is protected from changes, meaning it has been masked. It is time to apply filters to the crystal’s background and there are a plethora of Photoshop filters to play with. First, I am going to make the crystal’s background monochrome, therefore, from the top menu choose, Image then choose Adjustments then choose Desaturate, and just the background has changed to monochrome.
Remove Colour Tutorial Here!
7/
Alternatively, (first, from the top menu choose Edit then choose Step Backwards), then apply a different filter to the background. For example, from the top menu, choose Filter then from the drop-down list choose a filter you like the sound of. I am choosing the (default) Mosaic Tile filter found in the Textures tab.
8/
For the following effect, I applied the Fibres filter (with a high setting), then applied a Perspective Shadow from Eyecandy 5 Impact. Perspective Shadows Tutorials.
9/
Finish by applying a Sharpen filter to the crystal - from the top menu, choose Filter then choose Sharpen and choose a filter - sharpen images lesson - then save your work.
Wendi E M Scarth. Top of Page - Home.
|
|
